DESIGNING TRIANIONIC PINCER AND PINCER-TYPE LIGANDS …

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DESIGNING TRIANIONIC PINCER AND PINCER-TYPE LIGANDS FOR APPLICATIONS IN AEROBIC OXIDATION, C−H BOND ACTIVATION, AND ALKYNE

METATHESIS

By

MATTHEW ELIJAH O’REILLY

A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT

OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY

UNIVERSITY OF FLORIDA

2013

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© 2013 Matthew E. O’Reilly

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To my family

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ACKNOWLEDGMENTS

Upon realizing this accomplishment, I am deeply grateful for those who

developed me as a person and as a chemist. First, I thank my mother and father for

their unconditional love and support throughout these years. I am thankful to my five

brothers, who instilled in me a competive spirit. In particular, my little brother Thomas,

who is far more intelligent than me, used sibling rivalry to push me to study at an early

age.

I thank Lee University for providing a reasonably priced education that my

parents could afford and some of my most influental mentors. One of those mentors is

my organic chemistry professor, Edward Brown, who fostered my passion for chemistry.

Additionaly, I am also grateful for the opportunities to work as a REU student in the

research laboratories of Prof. Gunnoe and Prof. Braunstein.

I am thankful for my good friend and research mentor, Roberto Pattacini, who

taught me many synthetic skills. I thank my advisor, Adam S. Veige, for his constant

guidance and advice, and the Veige group who have been supportive colleagues and

good friends. Also, I wish to thank and acknowledge two undergraduate students,

Joseph Falkowski and Trevor del Castillo, who have contributed to the work presented

here.

I want to thank three people who deserve special recognition. My brother

Thomas mentioned earlier. My lovely wife Olivia, you have given me the greatest

happiness. You have provided an unwavering support and taught me to discipline my

life and my passion for chemistry. I thank God for you and look forward to life’s

adventures together. My grandfather John Galiger, you taught me to be content, to

forgive, and to strive, because “the cream always rises to the top.” Finally I want to

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thank the Big Man upstairs, who has given me the ability to understand his masterwork

and has provided all these opportunities.

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TABLE OF CONTENTS page

ACKNOWLEDGMENTS .................................................................................................. 4

LIST OF TABLES .......................................................................................................... 11

LIST OF FIGURES ........................................................................................................ 15

LIST OF ABBREVIATIONS ........................................................................................... 29

ABSTRACT ................................................................................................................... 33

CHAPTER

1 INTRODUCTION INTO TRIANIONIC PINCER AND PINCER-TYPE LIGANDS .... 35

1.1 Pincer and Pincer-Type Ligands ....................................................................... 35

1.2 Developing Trianionic Pincer and Pincer-Type Ligands .................................... 35 1.2.1 Pincer Ligands for High Oxidation State Metals ...................................... 35 1.2.2 Versatility of the Trianionic Pincer and Pincer-type Ligand ...................... 36

1.3 Rational Approaches to Create Reactive Complexes ....................................... 38 1.3.1 Confined Medional Geometry with Early Transition Metals ..................... 38

1.3.2 Constrained Bite Angles of Trianionic Pincer Ligands ............................. 39 1.3.3 Open Coordination Site ........................................................................... 40

1.3.4 Insertion of Unsaturated Substrate into Central Pincer M-C Bond .......... 41 1.3.5 Electronically Unsaturated Metal Centers ................................................ 41 1.3.6 Constrained Donor Atom Orientation....................................................... 41

1.3.7 Support High Oxidation State Metals....................................................... 42 1.3.8 Redox-active Pincer Ligands ................................................................... 42

1.4 Designing Trianionic Pincer and Pincer-type Ligands for Applications in Aerobic Oxidation, C−H Bond Activation, and Alkyne Metathesis. ...................... 43

2 AEROBIC OXIDATION CATALYST FEATURING BY A TRIANIONIC PINCER CrIII/CrV COUPLE AVOIDING COMMON CATALYST DEACTIVATION PATHWAYS ............................................................................................................ 49

2.1 Introduction ....................................................................................................... 49 2.2 Results and Discussion ..................................................................................... 51

2.2.1 Synthesis of [tBuOCO]HK2•1.5 THF (1) and [tBuOCO]CrIII(THF)3 (2) ...... 51 2.2.2 Synthesis of [tBuOCO]Cr(≡O)(THF) (3) ................................................... 53 2.2.3 Aerobic Oxidation of PPh3 Catalyzed by [tBuOCO]Cr(≡O)(THF) (2) ........ 55

2.2.4 Prelude to the Kinetic Investigation into the Mechanism O2 Activation by 2 ............................................................................................................... 55

2.2.5 UV-vis Measurements for the Rate of O2 Activation by 2 ........................ 56 2.2.6 O2 Cleavage Rate Dependence on [2], [O2], [THF], and Temperature .... 56

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2.2.7 Characterization of the Autocatalytic Intermediate: the Chromium(IV) μ-oxo Dimer {[tBuOCO]CrIV(THF)}2(μ-O) (4) .................................................. 58

2.2.8 Electron Paramagnetic Resonance Measurements of 4 .......................... 60

2.2.9 Proposed Mechanism of O2 Activation .................................................... 62 2.2.10 Kinetic Simulations ................................................................................ 63 2.2.11 Product Inhibition Studies ...................................................................... 65 2.2.12 Isolation of a Catalytic Intermediate [tBuOCO]Cr(OPPh3)2 (5) ............... 65

2.2.13 Cyclic Voltametry of 2, 4, and 5 ............................................................. 66

2.3 Conclusions ...................................................................................................... 67 2.4 Experimental Section ........................................................................................ 68

2.4.1 General Considerations ........................................................................... 68 2.4.2 Analytical Techniques .............................................................................. 69 2.4.3 Calculations ............................................................................................. 70 2.4.4 Synthesis of [tBuOCO]K2▪1.5THF (1) ...................................................... 71 2.4.5 Synthesis of [tBuOCO]CrIII(THF)3 (2) ....................................................... 71

2.4.6 Synthesis of [tBuOCO]CrV≡O(THF) (3) .................................................... 72 2.4.7 Synthesis of {[tBuOCO]CrIV(THF)}2(μ-O) (4) ............................................ 73

2.4.8 Synthesis of [tBuOCO]CrIII(OPPh3)2 (5) ................................................... 73

2.4.9 General Procedure for the Catalytic Oxidation of PPh3 with O2 by 2 ....... 73

2.4.10 General Procedure for the Catalytic Oxidation of PPh3 with air by 2 ..... 74 2.4.11 Stoichiometric 18O2 Catalytic PPh3 Oxidation Reaction ......................... 74

2.4.12 General Sample Preparation for Kinetic Measurements ........................ 74 2.4.13 Kinetic Simulations ................................................................................ 75

2.4.14 [2] vs time: Oxidation of 2 with O2 in THF .............................................. 75 2.4.15 Variable Temperature: Oxidation of 2 with O2 in THF ............................ 76

3 THE INFLUENCE OF REVERSIBLE TRIANIONIC PINCER OCO3- μ-OXO CrIV DIMER FORMATION ([CrIV]2(μ-O)) AND DONOR LIGANDS IN OXYGEN-ATOM-TRANSFER (OAT) ...................................................................................... 96

3.1 Introduction ....................................................................................................... 96 3.2 Results and Discussion ..................................................................................... 98

3.2.1 Identity of the Active OAT Agent in THF .................................................. 98 3.2.2 Mechanism of OAT from Mononuclear 3 and 3a ..................................... 99 3.2.3 [PPh3] Dependence ............................................................................... 100 3.2.4 Variable Temperature Studies and Eyring Plot ...................................... 100 3.2.5 PR3 Size Rate Dependence .................................................................. 100

3.2.6 Role of Donor Ligands on OAT ............................................................. 101 3.2.7 Synthesis and Characterization of [tBuOCO]CrV(O)(CH2PPh3) (6) ........ 102 3.2.8 Role of Dinuclear μ-oxo Dimer {[tBuOCO]CrIV(THF)}2(μ-O) (4) in OAT .. 103

3.3 Conclusions .................................................................................................... 107 3.4 Experimental Section ...................................................................................... 109

3.4.1 General Considerations ......................................................................... 109

3.4.2 Analytical Techniques ............................................................................ 110 3.4.3 Synthesis of [tBuOCO]CrVO(CH2PPh3) (6) ............................................ 111 3.4.4 [PPh3] vs. kobs. [

tBuOCO]CrV(O)(THF) (3) in THF .................................. 112 3.4.5 [OPPh3] vs. kobs. [

tBuOCO]CrV(O)(THF) (3) in THF ................................ 112

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3.4.6 Variable Temperature. [tBuOCO]CrV(O)(THF) in THF ........................... 112

3.4.7 Solvent Effects. OAT in MeCN, CH2Cl2, and THF ................................. 113 3.4.8 Substrate Effects. OAT to PMe3, PPh3, and PtBu3 ................................ 113

3.4.9 [PPh3] vs kobs: OAT from {[tBuOCO]CrIV(THF)}2(μ-O ) (4) to PPh3 in CH2Cl2 ......................................................................................................... 114

4 REACTIONS OF AN ONO3- TRIANIONIC PINCER-TYPE TUNGSTEN ALKYLIDYNE WITH ALKYNES AND NITRILES: PROBING AN UNUSUALLY STABLE TUNGSTENABUTADIENE..................................................................... 126

4.1 Introduction ..................................................................................................... 126

4.2 Results and Discussion ................................................................................... 129

4.2.1 Synthesis and Characterization of [CF3-ONO]H3 (8) .............................. 129 4.2.2 Synthesis and Characterization of [CF3-ONO]W=CH(tBu)(OtBu) (9) ..... 129

4.2.3 Synthesis and Characterization of {[CF3-ONO]W≡C(tBu)(OtBu)}{MePPh3} (10) ......................................................... 130

4.2.4 In-situ Synthesis of {CH3PPh3}{[CF3-ONO]W≡CtBu(OTf)} (11) and [CF3-ONO]W≡C(tBu)(OEt2) (12) .................................................................. 130

4.2.5 Synthesis and Characterization of [CF3-ONO]W[κ2-C(tBu)C(Me)C(Ph)] (13) .............................................................................................................. 132

4.2.6 Synthesis and Characterization of [CF3-ONO]W[κ2-C(tBu)C(Me)C(tBu)] (14) .............................................................................. 134

4.2.7 Synthesis and Characterization of [CF3-ONO]W[κ2-C(tBu)C(CH2(CH2)4CH2)C] (15) ................................................................... 135

4.2.8 Computational Studies .......................................................................... 137

4.2.9 15N NMR Studies ................................................................................... 139 4.2.10 Electronic Factors Contributing to an Irreversible [2+2]-Cycloaddition 140 4.2.11 Nitrile-Alkyne Cross Metathesis ........................................................... 141

4.3 Conclusion ...................................................................................................... 142 4.4 Experimental ................................................................................................... 144

4.4.1 General Considerations ......................................................................... 144 4.4.2 Analytical Techniques ............................................................................ 144

4.4.3 Calculations ........................................................................................... 144 4.5.4 Synthesis of 2,2'-(azanediylbis(3-methyl-6,1-

phenylene))bis(1,1,1,3,3,3-hexafluoropropan-2-ol) (8) ................................ 145 4.4.5 Synthesis of [CF3-ONO]W=CHtBu(OtBu) (9) ......................................... 146 4.4.6 Synthesis of {CH3Ph3P}{[CF3-ONO]W≡CtBu(OtBu)} (10)....................... 147

4.4.7 Synthesis of {CH3PPh3}{[CF3-ONO]W≡CtBu(OTf)}•0.5 {CH3PPh3}{OTf} (11) .............................................................................................................. 148

4.4.8 Synthesis of [CF3-ONO]W(≡CtBu)(OEt2) (12) ........................................ 148 4.4.9 Synthesis of [CF3-ONO]W[κ2-C(tBu)C(Me)C(Ph)] (13) .......................... 149 4.4.10 Synthesis of [CF3-ONO]W[κ2-C(tBu)C(Me)C(tBu)] (14) ........................ 150

4.4.11 Synthesis of [CF3-ONO]W[κ2-C(tBu)C(CH2(CH2)4CH2)C] (15) ............. 151

5 AN ONO3- TRIANIONIC PINCER-TYPE LIGAND FOR GENERATING HIGHLY NUCLEOPHILIC METAL-CARBON MULTIPLE BONDS: AN INORGANIC ENAMINE ............................................................................................................. 164

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5.1 Introduction ..................................................................................................... 164 5.2 Results ............................................................................................................ 168

5.2.2 Synthesis and Characterization of [CF3-ONO]W=CH(Et)(OtBu) (16) ..... 168

5.2.3 Synthesis and Characterization of {[CF3-ONO]W≡C(Et)(OtBu)}{MePPh3} (17) ........................................................... 170

5.2.4 Reactivity Studies, Nucleophilic at Carbon ............................................ 170 5.2.5 Isobutylene Expulsion from 17 .............................................................. 171 5.2.6 Catalytic Isobutylene Expulsion from 16 ................................................ 171

5.2.7 Computational Results .......................................................................... 172 5.3 Discussion ...................................................................................................... 174

5.3.1 An Enhanced Nucleophilic Reactivity from 17 ....................................... 174 5.3.2 Single Point DFT Calculations of 17 ...................................................... 174 5.3.3 Isobutylene Expulsion from 10 .............................................................. 175 5.3.4 Isobutylene Expulsion from 16 .............................................................. 177

5.4 Conclusion ...................................................................................................... 178

5.5 Experimental ................................................................................................... 179

5.5.1 General Considerations ......................................................................... 179 5.5.2 Analytical Techniques ............................................................................ 179 5.5.3 Calculations ........................................................................................... 179 5.5.5 Synthesis of [CF3-ONO]W=CH(Et)(OtBu) (16) ....................................... 180 5.5.6 Synthesis of {[CF3-ONO]W≡C(Et)(OtBu)}{MePPh3} (17) ....................... 181

5.5.7 Preparation of [CF3-ONO]W=C(CH3)(Et)(OtBu) (18) ............................ 181

5.5.8 Preparation of [CF3-ONO]W=CH(Et)(OSiMe3) (19) ............................... 182 5.5.9 Synthesis of [CF3-ONO]W(O)(nPr) (20) ................................................. 183

6 FUTURE WORK TOWARDS AN ACTIVE ALKYNE METATHESIS CATALYST FEATURING A NEW TRIANIONIC ONO PINCER-TYPE LIGAND. ..................... 195

6.1 Introduction ..................................................................................................... 195 6.2 Results and Discussion ................................................................................... 195

6.2.1 Progess towards the Synthesis of [pyr-ONO]H3 .................................... 195 6.3 Experimental ................................................................................................... 197

6.3.1 General Considerations ......................................................................... 197 6.3.2 Analytical Techniques ............................................................................ 197 6.3.3 Synthesis of 2,5-bis(3-(tert-butyl)-2-methoxyphenyl)-1H-pyrrole ........... 197

APPENDIX: SUPPORTING INFORMATION .............................................................. 202

A.1 NMR Data ....................................................................................................... 202

A.2 IR Data ........................................................................................................... 282 A.3 UV-Vis Data .................................................................................................... 286 A.4 MS Data ......................................................................................................... 287 A.5 EPR Data ....................................................................................................... 289

A.6 CV Data .......................................................................................................... 290

A.7 X-Ray Crystallographic Data .......................................................................... 291 A.8 DFT Calculations ............................................................................................ 363

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LIST OF REFERENCES ............................................................................................. 379

BIOGRAPHICAL SKETCH .......................................................................................... 401

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LIST OF TABLES

Table page 2-1 Average calculated rate constants for the oxidation of 2 (1.84 x10-4 M) with

O2 (1.66 x10-3 M) in THF at 25 °C, 20 °C, and 0 °C. .......................................... 92

3-1 Rate constants for OAT of 3a (0.30 mM) to PMe3, PPh3, and PtBu3 (0.77 mM) in THF at 15°C. –d[3a]/dt = kobs[3a] where kobs (s

-1) = k1[phosphine]. ............... 118

3-2 Rate constants for OAT of 3 (2.97 x10-4 M) to PPh3 (7.70 x10-4 M) at 22 °C. –d[3]/dt = kobs[3] where kobs = k1[PPh3]. ............................................................ 119

3-3 Simulated k1 (s-1) and k-1 (M

-1s-1) values obtained from the simulation of the [3] vs time plots. (CH2Cl2, 22°C) ....................................................................... 124

4-1 Selected metric parameters for the WC3 rings of 19, 20, and 21. ..................... 158

4-2 Selected metric parameters for the WC3 rings of 19, 20, and 21. ..................... 158

4-3 15N NMR chemical shifts of 9-15. ..................................................................... 162

5-1 Selected bond lengths (Å) for the single crystal X-ray structure of 9 and DFT geometry optimized structures of 16', 16-Me', and 17'. .................................... 189

A-1 1H, 13C, 19F and 15N chemical shifts in compounds 8-15. ................................. 209

A-2 1H, 13C, 19F and 15N chemical shifts in compounds 8,16-20 in C6D6. ................ 245

A-3 Crystal data, structure solution and refinement for 1. ....................................... 293

A-4 Atomic coordinates ( x 104) and equivalent isotropic displacement

parameters (Å2x 103) for 1.. ............................................................................. 294

A-5 Bond lengths (in Å) for 1. .................................................................................. 295

A-6 Bond angles (°) for 1. ........................................................................................ 295

A-7 Anisotropic displacement parameters (Å2x 103) for 1. .................................... 298

A-8 Crystal data and structure refinement for 2. ..................................................... 300


parameters (Å2x 103) for 2. .............................................................................. 301

A-10 Bond lengths [Å] for 2. ...................................................................................... 302

A-11 Bond angles [°] for 2. ........................................................................................ 303

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A-15 Bond length [Å] for 3. ........................................................................................ 308

A-16 Bond angles [°] for 3. ........................................................................................ 309


A-18 X-ray crystallographic structure parameters and refinement data for 4. ........... 312

A-19 Atomic coordinates (x 104) and equivalent isotropic displacement



A-21 Bond angles [°] for 4. ........................................................................................ 314






A-26 Bond angles [°] for 5. ........................................................................................ 320






A-31 Bond angles [°] for 6. ........................................................................................ 327


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A-33 Crystal data and structure refinement for 12. ................................................... 331


parameters (Å2x 103) for 12.. ........................................................................... 332

A-35 Bond angles [°] for 12. ...................................................................................... 333

A-36 Bond lengths [Å] for 12. .................................................................................... 334

A-37 Anisotropic displacement parameters (Å2x 103) for 12. .................................. 334





A-41 Bond angles [°] for13. ....................................................................................... 339






A-46 Bond angles [°] for 14. ...................................................................................... 345



A-49 Atomic coordinates ( x 104) and equivalent isotropic displacement parameters (Å2x 103) for 15.. ........................................................................... 349


A-51 Bond angles [°] for 15. ...................................................................................... 351



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A-56 Bond angles [°] for 16. ...................................................................................... 356






A-61 Bond angles [°] for 20. ...................................................................................... 361


A-63 Atomic coordinates for the geometry optimized structure of 12. ....................... 363

A-64 Atomic coordinates for the geometry optimized structure of 13. ....................... 364

A-65 Atomic coordinates for the geometry optimized structure of [CF3-ONO]W≡N(OEt2). ............................................................................................. 366

A-66 Atomic coordinates of the geometry optimization calculation for 16’. ............... 369

A-67 Atomic coordinates of the geometry optimization calculation for 16-Me’. ......... 371



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LIST OF FIGURES

Figure page 1- 1 The original PCP pincer ligand (A) by Shaw,1 and PNP pincer-type ligand

(B) by Ozerov.2 ............................................................................................... 45

1- 2 A coordinately-saturated high valent metal (M) featuring a pincer ligand A and a low-coordinate high valent metal with a trianionic pincer ligand B. ....... 45

1- 3 Current library of demonstrated trianionic pincer ligands; and pincer-type ligands. ........................................................................................................... 46

1- 4 Coordination geometry changes upon imposing a trianionic pincer ligand on a tetrahedral metal center. ......................................................................... 47

1- 5 Bite angles and linker spacing. ....................................................................... 47

1- 6 Creating open coordination sites. ................................................................... 47

1- 7 Insertion into the OCO pincer C-M bond.. ...................................................... 48

1- 8 Constrained amido orientation using trianionic pincer-type ligand. ................. 48

1- 9 Potential redox states of a non-innocent pincer-type ligand. .......................... 48

2- 1 General mechanism for substrate oxidation including catalyst deactivation pathways of product inhibition and reversible formation of a M-O-M intermediate. ................................................................................................... 77

2- 2 Additional coordination site provided by a trianionic pincer ligand over tetradentate ligands. ....................................................................................... 77

2- 3 Synthesis of 1. ................................................................................................ 77

2- 4 Synthesis of 2. ................................................................................................ 78

2- 5 Molecular structure of 2 with ellipsoids at 50% probability. ............................. 78

2- 6 Activation of O2 by 2 to yield complex 3. ........................................................ 79

2- 7 Molecular structure of 3 with ellipsoids at 50% probability. ............................. 79

2- 8 Plot of the α-SOMO (A) and α-LUMO (B) of model complex 3′, contour level 0.03 a.u.. ................................................................................................ 80

2- 9 Aerobic oxidation of PPh3 catalyzed by complex 2. ........................................ 80

2- 10 UV-vis spectral change of 2 in THF upon addition of O2 (25 °C). ................... 81

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2- 11 Concentration vs time (s) for the oxidation of 2 by O2 in THF; within 1st 80% (blue), after 80% (red) (25 °C). ............................................................... 81

2- 12 Concentration (2) vs time (s) for the oxidation of 2 (0.55 – 1.65 (x10-4) M) with O2 (1.66 x10-3 M) in THF (25 °C). ............................................................ 82

2- 13 Plot of -Δ[2]/Δt vs [2] ([2] = 0.55 – 1.65 x10-4 M; [O2] = 1.66 x10-3 M (THF, 25 °C). ............................................................................................................ 82

2- 14 Concentration (2) vs time (s) for the oxidation of 2 (1.10 x10-4 M) with O2

(1.66 - 6.66 (x10-3) M) in THF (25 °C). ............................................................ 83

2- 15 Plot of rate -Δ[2]/Δt vs [O2] ([2] = 1.10 x10-4 M; [O2] = 1.66 - 6.66 (x10-4) M) in THF (25 °C). ............................................................................................... 83

2- 16 Plot of rate –Δ[1]/Δt vs XTHF ([2] = 1.10 x10-4 M; [O2] =1.66 x10-3 M; THF/hexane (mL:mL) = 2.5:0.5, 2.0:1.0, 1.5:1.5) at 25 °C. ............................ 84

2- 17 Concentration of 2 (1.84 x10-4 M) vs time in THF upon addition of O2 (1.66 x10-3 M) at 40 °C (red), 20 °C (yellow), 10 °C (light blue), and 0 °C (dark blue). .............................................................................................................. 84

2- 18 Concentration of 2 vs time (s) for the oxidation of 2 (1.10 x10-4 M) by O2 (1.66 x10-3 M) with increasing [3] (0, 5.5 x10-5, and 1.10 x10-5 M) in THF (25 °C). ........................................................................................................... 85

2- 19 Plot of Δ[2]/Δt for the oxidation of 2 (1.10 x10-4 M) by O2 (1.66 x10-3 M) with increasing [3] (0, 0.55 x10-4, and 1.10 x10-4 M) in THF (25 °C). .............. 85

2- 20 Equilibrium between 2 and 3 and the dimer adduct 5. .................................... 86

2- 21 Molecular structure of {[tBuOCO]CrIV(THF)}2O (5) with ellipsoids drawn at the 50% probability level.. ............................................................................... 86

2- 22 The π-bonding MO and ligand field splitting diagram of the CrIV ion in 5. ....... 87

2- 23 Variable temperature high frequency (240 GHz) powder EPR spectra of major 5 and minor 2. ....................................................................................... 87

2- 24 Simulated (a) and experimental (b) powder EPR spectra of 5 and 2 at 240 GHz and 4.5 K. ............................................................................................... 88

2- 25 Molecular structure of {[tBuOCO]CrIV(THF)}2O (5) with ellipsoids drawn at the 50% probability level. ................................................................................ 89

2- 26 Proposed mechanism for O2 activation by 2. .................................................. 90

2- 27 Simulated [2] (0.55 - 1.65 x10-4 M) vs time (s) at [O2] = 1.66 x10-3 M.. ........... 91

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2- 28 Simulated [2] (1.10 x10-4 M) vs time (s) at different concentrations of [O2] (1.66 – 6.66 x10-3 M).. .................................................................................... 91

2- 29 Simulated [2] vs time for the oxidation of 2 (1.65 x10-4 M and 1.84 x10-4 M) with O2 (1.66 x10-3 M) using the average calculated rate constants from Table 1. .......................................................................................................... 92

2- 30 A plot of [2] vs time with increasing [OPPh3] (0 – 0.1 M). [O2] = 1.66 x10-3

M and [2] = 1.10 x10-4 M (THF, 25 °C). .......................................................... 93

2- 31 Synthesis of 4. ................................................................................................ 93

2- 32 Molecular structure of 4 with ellipsoids at 50% probability. Hydrogen atoms and CH2Cl2 removed for clarity. ...................................................................... 94

2- 33 New general mechanism for substrate oxidation featuring . ........................... 95

3- 1 General mechanism for substrate oxidation that includes reversible formation of a M-O-M intermediate. .............................................................. 115

3- 2 EPR spectra (23 °C) of recrystallized [tBuOCO]CrV(O)(THF) (3) in toluene (blue, 1.29 mM) and 50:50 THF/CH2Cl2 (orange, 1.5 mM). .......................... 115

3- 3 Equilibrium between 3 and 3a. ..................................................................... 115

3- 4 Normalized EPR spectra (23 °C) of 3 in toluene (red), with 1 μL THF (green), and with 2 μL THF (blue). ............................................................... 116

3- 5 Oxygen-atom transfer reaction from 3a to PPh3. .......................................... 116

3- 6 UV-vis spectral change of 3a in THF upon addition of PPh3 and a plot of [3a] (0.11 mM) vs time (s) upon addition of PPh3 (1.1 mM) in THF. ............. 116

3- 7 A plot of ln[3a] vs time. ................................................................................. 117

3- 8 Plot depicting first-order dependency in [PPh3] (0.71 – 2.14 mM) for the OAT from 3a (0.11 mM) at 15 °C.. ................................................................ 117

3- 9 Eyring plot for the OAT from 3a (0.186 mM) to PPh3 (1.59 mM) in THF

between 0 – 40 ⁰C (R2 = 0.9875). ................................................................. 118

3- 10 Proposed mechanism for OAT. .................................................................... 118

3- 11 Zero-order dependency on [OPPh3] (0 - 1.31 mM) in the OAT from 3a (0.163 mM) to PPh3 (1.59 mM) in THF at 22 °C. .......................................... 119

3- 12 Synthesis of complex 6. ................................................................................ 119

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3- 13 Cyclic voltammograms of 3 in CH2Cl2 (red), and 6 in CH2Cl2 (blue) in 0.1 M TBAH/CH2Cl2 at 100 mVs-1; glassy carbon working and Ag/Ag+ reference electrodes. .................................................................................................... 120

3- 14 Solution EPR spectrum of 6 in hexanes (black) and simulated spectrum using EasySpin.3.1.6.. .................................................................................. 120

3- 15 Molecular structure of [tBuOCO]CrVO(CH2PPh3) (6) drawn in two perspectives.. ............................................................................................... 121

3- 16 UV-vis spectral change of 4 (purple) in CH2Cl2 upon addition of PPh3 (for reference the UV-vis spectra of 2 (green) and 3 (red) in THF are included). 121

3- 17 A plot of [4] (0.16 mM) vs time (s) and ln[4] vs time upon addition of PPh3 (1.10 mM) in CH2Cl2 (22°C). ......................................................................... 122

3- 18 A plot of 4 (1.56 x10-4 M) vs time upon the addition of PPh3 (1.10 – 4.42 x10-3 M) in CH2Cl2 (22 °C). ........................................................................... 122

3- 19 Proposed mechanism of OAT from 43- 19 to PPh3. ..................................... 123

3- 20 A plot of [4] (3.11, 1.56, and 0.78 x10-4 M) vs time (s) upon the addition of PPh3 (1.10 x10-3 M) in CH2Cl2. ..................................................................... 124

3- 21 The average 2[4] – [Cr]tot ln[4] vs time for the addition of PPh3 (1.1 x10-3 M) into a 3.31 x10-4 M solution of 4 in CH2Cl2. ............................................. 124

3- 22 Simulated (solid lines) and experimental (dotted lines) of [4] vs time at different concentration of 4 (0.78, 1.56, and 3.11 x10-4 M). .......................... 125

3- 23 Absorption spectrum of 3 (2.36 x10-4 M) in CH2Cl2 (red) and after (9.1 s) addition of PPh3 (1.87 x10-3 M) to form 4 (red). ............................................ 125

4- 1 Ancillary ligand rearrangement during alkyne metathesis. ........................... 153

4- 2 Delicate balance of lowering activation energy while keeping the alkylidyne and metallacyclobutadiene thermoneutral. ................................................... 153

4- 3 The push-pull electronic effect of the [CF3-ONO] pincer-type ligand and the inorganic enamine bonding structure. ........................................................... 153

4- 4 Initial proposed synthesis of an [CF3-ONO] ligand. ...................................... 154

4- 5 Synthesis of 8. .............................................................................................. 154

4- 6 Synthesis of 9. .............................................................................................. 154

4- 7 Synthesis of 10. ............................................................................................ 154

19

4- 8 Synthesis of 11 and 12. ................................................................................ 155

4- 9 Molecular structure of [CF3-ONO]W(≡CtBu)(OEt2) (12) with ellipsoids drawn at 50% Probability level, with hydrogens removed for clarity. ............ 155

4- 10 Synthesis of tungstenacyclobutadienes 13, 14, and 15. ............................... 156

4- 11 Molecular structure of [CF3-ONO]W[κ2-C(tBu)C(Me)C(Ph)] (19) with ellipsoids drawn at 50% probability level. ..................................................... 157

4- 12 Reported X-ray crystallographic bond length and angles of tungstenacyclobutadiene complexes. ........................................................... 157

4- 13 Fluxional WC3 ring conformations. ............................................................... 158

4- 14 Molecular structure of [CF3-ONO]W[C(tBu)C(Me)C(tBu)] (14) with ellipsoids drawn at 50% probability level.. .................................................... 159

4- 15 Molecular structure of [CF3-ONO]W[C(tBu)C(CH2)6C] (15) with ellipsoids drawn at 50% probability level. ..................................................................... 159

4- 16 DFT geometry optimized structures of 12 and 13 with calculated bond lengths (red) and crystallographic determined lengths (black). .................... 160

4- 17 Truncated MO diagram of 12 and 13. (isovalues = 0.051687). ..................... 161

4- 18 Amido lone pair orientation for varying ligand systems of tungsten alkylidyne and tungstenacyclobutadiene complexes (I, II,304, 305 and III304). .. 162

4- 19 Reaction progress vs free energy diagram for retro-[2+2]-cycloaddition. ..... 163

4- 20 Nitrile-alkyne cross metathesis upon treating 18 with MeCN. ....................... 163

5- 1 Amido p-orbital aligned with dxy and amido p-orbital rotated out of alignment. ..................................................................................................... 185

5- 2 Two possible resonance contributions for an enamine and amidoalkylidene. ........................................................................................... 185

5- 3 Truncated qualitative orbital diagram of the bonding analogy between enamines374 and amidoalkylidenes. .............................................................. 185

5- 4 Push-pull synergetic effect of the [CF3-ONO]3- pincer-type ligand. ............... 186

5- 5 Synthesis of 16. ............................................................................................ 186

5- 6 Molecular structure of [CF3-ONO]W=CH(Et)(OtBu) (16) with ellipsoids drawn at the 50% probability level. ............................................................... 186

20

5- 7 Synthesis of 17. ............................................................................................ 187

5- 8 Methylation of 17 to form 18. ........................................................................ 187

5- 9 Isobutylene expulsion from 17 to form 19. .................................................... 187

5- 10 Lewis acid catalyzed isobutylene expulsion from 16 to form 20. .................. 188

5- 11 Molecular structure of [CF3-ONO]W(O) nPr (20) with ellipsoids drawn at the 50% probability level. .................................................................................... 188

5- 12 Geometry optimized structures for 16', 16-Me', and 17'. ............................... 189

5- 13 The HOMO, HOMO(-1), and HOMO(-2) orbitals of 17' (Isovalue = 0.051687). .................................................................................................... 190

5- 14 The HOMO, HOMO(-1), and HOMO(-2) orbitals of 17'; and the HOMO, HOMO(-1), and HOMO(-2) orbitals of 21' (Isovalue = 0.051687). ................ 191

5- 15 Proposed mechanism for isobutylene expulsion from 17. ............................ 192

5- 16 Proposed mechanism for isobutylene expulsion from 16 (LA = Me+, Me3Si+, and B(C6F5)3. ................................................................................... 193

5- 17 Truncated X-ray structure of 16 and geometry optimized structure 16-Me' illustrating the 77° rotation of the W=C bond. ............................................... 193

5- 18 The HOMO, HOMO(-1), and HOMO(-5) orbitals of 16-Me' (Isovalue = 0.051687). .................................................................................................... 194

6- 1 Proposed alkyne metathesis catalyst featuring a trianionic [pyr-ONO] pincer-type ligand. ........................................................................................ 200

6- 2 Proposed synthesis of [pyr-ONO] pincer-type ligand (red arrows) and actual outcome. ............................................................................................ 200

6- 3 Proposed synthesis of [pyr-ONO] pincer-type ligand (red arrows) and actual outcome. ............................................................................................ 201

A- 1 1H NMR Spectra of 1 obtained in THF-d8. .................................................... 202

A- 2 13C{1H} NMR Spectra of 1 obtained in THF-d8 .............................................. 202

A- 3 1H NMR spectrum of 2 in C6D6. .................................................................... 203



21

A- 6 1H NMR of 5 in C6D6. .................................................................................... 206

A- 7 1H NMR of 5 dissolved in THF-d8 to form 2 (characteristic peaks = 8.20, -7.44, -13.23 ppm) and 3. .............................................................................. 206

A- 8 1H NMR of 6 in C6D6 with 0.01 mL THF-d8. .................................................. 207

A- 9 1H NMR of 5 (2.43 x10-5 mol) in C6D6 (red) and with OPPh3 (5.82 x10-5) in C6D6 (blue). .................................................................................................. 207

A- 10 Labelling scheme for 1H and 13C NMR peaks. .............................................. 208

A- 11 1H NMR (CDCl3, 300 MHz) spectrum of 8. .................................................... 212

A- 12 Variable Temperature 19F{1H} NMR (CDCl3, 300 MHz) spectrum of 8 at 25 °C (blue), 35 °C (green), 45 °C (gray), and 55 °C (red). ............................... 212

A- 13 13C{1H} NMR (CDCl3, 300 MHz) spectrum of 8. ............................................ 213

A- 14 13C{19F} NMR (CDCl3, 300 MHz) spectrum of 8. ........................................... 213

A- 15 1H-13C gHMBC (C6D6, 500 MHz) spectrum of 8. ........................................... 214

A- 16 1H-13C gHMBC (C6D6, 500 MHz) spectrum of 8, expanded. ......................... 214

A- 17 1H-15N gHMBC (C6D6, 500 MHz) spectrum of 8. ........................................... 215

A- 18 19F-13C gHSQC (C6D6, 500 MHz) spectrum of 8. .......................................... 215


A- 20 19F{1H} NMR spectrum of 9 in C6D6. ............................................................. 216

A- 21 1H{13C} gHSQC NMR spectrum of 9 in C6D6. ............................................... 217

A- 22 1H{13C} gHMBC NMR spectrum of 9 in C6D6. ............................................... 217

A- 23 1H{15N} gHMBC NMR spectrum of 9 in C6D6. ............................................... 218

A- 24 19F{1H} NMR spectra of 9 in C6D6 (bottom) and with selective decoupling (top). ............................................................................................................. 218

A- 25 19F{13C} gHMBC NMR spectrum of 9 in C6D6, expanded. ............................ 219

A- 26 19F{13C} gHSQC NMR spectrum of 9 in C6D6, expanded. ............................. 219

A- 27 19F{13C} gHSQC NMR spectrum of 9 in C6D6, expanded. ............................. 220

A- 28 1H NMR spectrum of 10 in C6D6. .................................................................. 220

22

A- 29 19F{1H} NMR spectrum of 10 in C6D6. ........................................................... 221

A- 30 31P{1H} NMR spectrum of 10 in C6D6. ........................................................... 221

A- 31 1H{13C} gHSQC NMR spectrum of 10 in C6D6. ............................................. 222

A- 32 1H{13C} gHMBC NMR spectrum of 10 in C6D6. The signals at 278.5 and 16.0 in f1 are 8.5 and 286.0, foled. ............................................................... 222

A- 33 1H{15N} gHMBC NMR spectrum of 10 in C6D6. ............................................. 223


A- 35 19F{13C} gHMBC NMR spectrum of 10 in C6D6, expanded. .......................... 224



A- 38 31P{1H} NMR spectrum of 11 in C6D6. ........................................................... 225

A- 39 1H{13C} gHMBC NMR spectrum of 11 in C6D6. ............................................. 226

A- 40 1H{13C} gHMBC NMR spectrum of 11 in C6D6, expanded. ........................... 226



A- 43 1H{15N} gHMBC NMR spectrum of 11 in C6D6, expanded. ........................... 228

A- 44 19F{13C} gHMBC NMR spectrum of 11 in C6D6, expanded. .......................... 228

A- 45 19F{13C} gHSQC NMR spectrum of 11 in C6D6. ............................................ 229








23

A- 53 1H{15N} gHMBC NMR spectrum of 12 in C6D6, expanded. ........................... 233


A- 55 19F{13C} gHMBC NMR spectrum of 12 in C6D6. ............................................ 234




A- 59 13C{1H} NMR spectrum of 13 in C6D6............................................................ 236














A- 73 19F{13C} gHMBC NMR spectrum of 15 in C6D6. ............................................ 243


A- 75 1H NMR spectrum of 12 in C6D6 and 15 equiv. of MeCN. (tBuCCMe = 1.54 and 1.20 ppm; 14 = 3.13 and 1.18 ppm). ..................................................... 244

24

A- 76 19F{1H} NMR spectrum of 12 in C6D6 and 15 equiv. of MeCN (blue) along with 19F{1H} NMR spectrum of 14 (red) ......................................................... 244

A- 77 Labelling scheme for 1H and 13C NMR peaks. .............................................. 245

A- 78 1H NMR (C6D6, 300 MHz) spectrum of 16. ................................................... 248

A- 79 19F{1H} NMR (C6D6, 300 MHz) spectrum of 16. ............................................ 248

A- 80 19F{1H} NMR (C6D6, 300 MHz) spectrum of 16 with selective decoupling at 73.9 ppm. ..................................................................................................... 249

A- 81 13C{1H} NMR (C6D6, 300 MHz) spectrum of 16. ............................................ 249

A- 82 1H-1H gDQFCOSY (C6D6, 500 MHz) spectrum of 16, expanded. ................. 250

A- 83 1H-1H gDQFCOSY (C6D6, 500 MHz) spectrum of 16, full. ............................ 250

A- 84 1H-13C gHSQC (C6D6, 500 MHz) spectrum of 16, expanded. ....................... 251


A- 86 1H-13C gHMBC (C6D6, 500 MHz) spectrum of 16, full. .................................. 252

A- 87 1H-13C gHMBC (C6D6, 500 MHz) spectrum of 16, expanded. ....................... 252



A- 90 1H-15N gHMBC (C6D6, 500 MHz) spectrum of 16. ........................................ 254

A- 91 19F-13C gHSQC (C6D6, 500 MHz) spectrum of 16, expanded. ...................... 254


A- 93 19F-13C gHMBC (C6D6, 500 MHz) spectrum of 16, expanded. ...................... 255



A- 96 31P{1H} NMR (C6D6, 300 MHz) spectrum of 17. ............................................ 257

A- 97 1H-13C gHSQC (C6D6, 500 MHz) spectrum of 17. ......................................... 257

A- 98 1H-13C gHMBC (C6D6, 500 MHz) spectrum of 17. ........................................ 258


25







A- 106 19F-13C gHMBC (C6D6, 500 MHz) spectrum of 17, expanded. ...................... 262


A- 108 1H-1H gDQFCOSY (C6D6, 500 MHz) spectrum of 18. ................................... 263

A- 109 1H-1H gDQFCOSY (C6D6, 500 MHz) spectrum of 18, expanded. ................. 263






A- 115 19F-19F gDQFCOSY (C6D6, 500 MHz) spectrum of 18. ................................. 266





A- 120 1H-1H gDQCOSY (C6D6, 500 MHz) spectrum of 19. ..................................... 269

A- 121 1H-13C gHSQCAD (C6D6, 500 MHz) spectrum of 19, expanded. .................. 269

A- 122 1H-13C gHSQCAD (C6D6, 500 MHz) spectrum of 19, expanded. .................. 270

A- 123 1H-13C gHMBCAD (C6D6, 500 MHz) spectrum of 19..................................... 270

A- 124 1H-13C gHMBCAD (C6D6, 500 MHz) spectrum of 19, expanded. .................. 271

26



A- 127 1H-15N gHMBCAD (C6D6, 500 MHz) spectrum of 19, expanded. .................. 272


A- 129 19F-19F gDQCOSY (C6D6, 500 MHz) spectrum of 19. ................................... 273

A- 130 19F-13C gHSQCAD (C6D6, 500 MHz) spectrum of 19, expanded. ................. 274




A- 134 19F NMR (C6D6, 300 MHz) spectrum of 20. .................................................. 276

A- 135 13C{1H} NMR (C6D6, 300 MHz) spectrum of 20. ............................................ 276

A- 136 1H -13C gHMBC (C6D6, 500 MHz) spectrum of 20, expanded. .................. 277

A- 137 1H -13C gHMBC (C6D6, 500 MHz) spectrum of 20, expanded. ...................... 277



A- 140 1H -15N gHMBC (C6D6, 500 MHz) spectrum of 20. ........................................ 279

A- 141 19F{1H} NMR (C6D6, 500 MHz) spectrum of 20 (bottom) and spectra with selective homonuclear decoupling (top). ...................................................... 279

A- 142 1H NMR (CDCl3, 500 MHz) spectrum of 22................................................... 280

A- 143 13C{1H} NMR (CDCl3, 500 MHz) spectrum of 22. .......................................... 280



A- 146 IR spectrum of 2 (thin film). ........................................................................... 282

A- 147 IR spectrum of 3 (thin film). .......................................................................... 282



27



A- 152 IR spectrum of 16 (thin film). ........................................................................ 285

A- 153 IR spectrum of 17 (thin film). ........................................................................ 285

A- 154 UV-vis spectra of 5 in toluene (1.79 and 8.94 x10-5 M) ................................. 286

A- 155 UV-vis of 6 in THF (0.057 mM, red; 0.113 mM, blue). .................................. 286

A- 156 DART mass spectroscopy spectra of 18OPPh3. ............................................ 287

A- 157 ESI-TOF mass spectroscopy spectra of 8. ................................................... 287

A- 158 GC-CI mass spectroscopy spectra of 22. ..................................................... 288

A- 159 ESI mass spectroscopy spectra of 23. ......................................................... 288

A- 160 EPR spectrum of 3 (10 mM solution, toluene) at T = 298 K.......................... 289

A- 161 Individually simulated spectra of an S = 2 (a) and an S = 1.5 (b) systems are added together to get the total spectrum (c) corresponding to the mixture of the dimer (4) and monomer (2). ................................................... 289

A- 162 Solution EPR of a mixture of 3 and 3a (5.0 x10-3 M) in toluene (blue) and a 3 and 3a solution (1.6 x10-3 M) in toluene (blue) with the addition of 6 equiv. MeCN (red). ....................................................................................... 290

A- 163 Cyclic voltammograms of 5 x10-3 M solution of 2, 4, and 5 in 0.1 M TBAH/CH2Cl2 at 100 mVs-1; glassy carbon working and Ag/Ag+ reference electrodes. .................................................................................................... 290

A- 164 Molecular structure of 1. Hydrogen atoms are omitted for clarity................. 291

A- 165 Molecular structure of 2 with ellipsoids drawn at the 50% probability level. .. 299

A- 166 X-ray structure of 3 with ellipsoids drawn at the 50% probability level. ......... 306

A- 167 Molecular structure of 4 with ellipsoids drawn at the 50% probability level. .. 311

A- 168 X-ray structure of 5. ...................................................................................... 316

A- 169 Molecular Structure of 6. .............................................................................. 323

A- 170 Molecular Structure of 12. ............................................................................ 330


28





A- 176 Truncated molecular orbital diagram of [CF3-ONO]W≡N(OEt2). ................... 368

A- 177 Labeling Scheme of the geometry optimization structure for 16’. ................. 369

A- 178 Guassian optimized IR spectrum for 16’. ...................................................... 369

A- 179 Labelling Scheme of the geometry optimization calculation for 16-Me’. ....... 370

A- 180 Guassian optimizated IR spectrum calculation for 16-Me’. ........................... 371

A- 181 Labeling Scheme of the geometry optimization calculation for 17’. .............. 372

A- 182 Guassian optimizated IR spectrum calculation for 17’. ................................. 372

A- 183 Labeling Scheme of the geometry optimization calculation for 21’. .............. 374

A- 184 Guassian optimizated IR spectrum calculation for 21’. ................................. 374

A- 185 Molecular Orbital Diagram of 16-Me’ containing LUMO – HOMO(-5). (Isovalue = 0.051687) . ................................................................................. 376

A- 186 Molecular Orbital Diagram of 17’ containing LUMO – HOMO(-5). (Isovalue = 0.051687) . ................................................................................................ 377

A- 187 Molecular Orbital Diagram of 21’ containing LUMO – HOMO(-5). (Isovalue = 0.051687) . ................................................................................................ 378

29

LIST OF ABBREVIATIONS

AU

Hartree atomic units

C6D6

benzene-d6

C6H6

benzene

CF3-ONO 2,2'-(azanediylbis(3-methyl-6,1-phenylene))bis(1,1,1,3,3,3-hexafluoropropan-2-ol)

CH2Cl2 Dichloromethane

CV cyclic voltammetry

DFT differential fourier transform

DPPH 2,2-diphenyl-1-picrylhydrazyl

EPR

electron paramagnetic resonance

ESI-TOF

electron spray ionization-time of flight

Et2O

diethyl ether

FT-IR

fourier transform infrared

g

gram

gDQF-COSY

gradient double quantum filtered COSY

gHMBC

gradient heteronuclear multiple bond coherence

gHMBCAD

gradient heteronuclear multiple bond correlation with adiabatic pulse

gHSQC

gradient heteronuclear single quantum coherence

gHSQCAD

gradient heteronuclear single quantum correlation with adiabatic pulse

GHz

gigahertz

h

hours

30

HCl

hydrochloric Acid

HOMO

highest occupied molecular orbital

Hz

hertz

IR

infrared

K

rate constant

KCl

potassium chloride

Keq

equilibrium constant

kobs

observed rate constant

Ln

natural log

LUMO

lowest unoccupied molecular orbital

M

Molar

M—C

metal-carbon

Me

methyl

Me3SiOTf

trimethylsilyl triflate

MeCN

acetonitrile

MeOTf

methyl triflate

mg

milligram

min

minute

mmol

millimol

MO

molecular orbital

mol

mol

MS

mass spectrometry

NACM

nitrile-alkyne cross metathesis

31

n-BuLi

n-butylithium

nJ

coupling constant from n bonds away

NMR

nuclear magnetic resonance

OAT

oxygen-atom transfer

OPPh3

triphenylphosphine oxide

OTf

trifalte

P4O10

phosphorus pentoxide

Ph

phenyl

Ph3P=CH2

methylene(triphenyl)phosphorane

Ph3PCH3

methyltriphenyl)phosphonium

PPh3

triphenylphosphine

R

majority-spin

S

spin multiplicity

s

seconds

SOMO

singly occupied molecular orbital

t time

tbp

trigonal bipyramidal

tBu

tert-butyl

tBuOCO 3,3”-di-tert-butyl-[1,1’:3’,1”-terphenyl]-2,2”-diol

THF tetrahydrofuran

TOF

turnover frequency

TON

turnover number

UV vis

ultraviolet and visible light

32

WC3

tungstenabutadiene ring

X

molar ratio

Δ

difference in …

ΔH‡

enthalpy of activation

ΔS‡

entropy of activation

μL

Microliter

μmol

Micromole

ν1/2

width-at-half-height

33

Abstract of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy

DESIGNING TRIANIONIC PINCER AND PINCER-TYPE LIGANDS FOR

APPLICATIONS IN AEROBIC OXIDATION, C−H BOND ACTIVATION, AND ALKYNE METATHESIS

By

Matthew E. O’Reilly

August 2013

Chair: Adam S. Veige Major: Chemistry

Trianionic pincer and pincer-type ligands are an emerging class of multianionic

pincer ligands suited for high oxidation state metals (Mn+, n= 3-6). A defining feature of

trianionic pincer and pincer-type ligands is the rigid meridional coordination geometry,

which provides an open metal coordination site trans to the central pincer donor atom

that can be exploited for catalysis. These ligands are easily modified though the

selection of anionic donor atoms (e.g. C, O, N) and the ligand scaffold design. As such,

each trianionic pincer/pincer-type ligand imparts a unique reactivity to the metal center.

In this thesis, we explore the unique reactivity imparted by rationally designed trianionic

pincer/pincer-type ligands to (1) a chromium oxidation catalyst supported by a [tBuOCO]

ligand and (2) a tungsten alkylidyne featuring an [CF3-ONO] ligand for the applications

of alkyne metathesis and C−H bond activation.

[tBuOCO]CrIII(THF)3 (2) catalyzes the aerobic oxidation of PPh3 with an

exceptionally high turn-over number (TON). A kinetic investigation reveals that complex

2 avoids typical deactivation pathways. Complex 2 becomes more reactive toward O2

activation upon comproportionation with [tBuOCO]CrV(O)(THF) (3), yielding a unique

34

autocatalytic O2 activation mechanism. Probing product inhibition with OPPh3, the rate

of O2 activation by 2 surprisingly accelerates with higher concentrations of OPPh3.

The synthesis of an isolable CrVO and (CrIV)(μ-oxo) species presents interesting

models to investigate oxygen-atom transfer (OAT) reactions to phosphines. We present

the first kinetic investigation of OAT directly from a (CrIV)(μ-oxo) species and conclude a

unique role that the donor ligand plays during OAT.

A [CF3-ONO] trianionic pincer-type ligand supported tungsten alkylidyne (12)

reacts with alkynes to form exceptionally stable tungstenacyclobutadiene complexes

that do not undergo retro-[2+2]-cycloaddition. Contributing to the reactions’

irreversibility, complex 12 was found to be exceptionally destabilized by an unusual

orientation of the amido donor within the [CF3-ONO] trianionic pincer-type ligand. The

amido lone pair of electrons forms an inorganic version of an enamine within the metal

coordination sphere, enhancing the nucleophilicity of the W≡C bond. In Chapter 6, we

demonstrate the enhanced nucleophilicty with the tungsten alkylidene (16) and an

anionic tungsten alkylidyne (17) that activate the C−H bond of –OtBu to release

isobutylene.

35

CHAPTER 1 INTRODUCTION INTO TRIANIONIC PINCER AND PINCER-TYPE LIGANDS

1.1 Pincer and Pincer-Type Ligands

Trianionic pincer and pincer-type ligands are an emerging class of multianionic

tridentate ligands inspired from the traditional pincer ligand design.1 The quintessential

pincer design developed by Shaw et al.1 contains an anionic carbon donor between two

pendant arms bearing neutral phosphine donors (Figure 1-1), while pincer-type ligands

replace the central anionic carbon atom donor with an anionic heteratom (Figure 1-1).2

A defining feature of all pincer and pincer-type ligands is their confined meridional

coordination geometry of the tridentate ligand. Moreover, by virtue of the simplistic

design, pincer and pincer-type ligands are easily modified for specific applications.

Hence, slight changes to the pendant arms, the central donor atom, the chelate ring

size, and pincer framework allow for fine control over the electronic and steric

components imparted to the metal fragment.3 These relatively facile modifications make

pincer and pincer-type ligands a highly versatile ligand platform that can be engineered

for specific applications in catalysis, molecular sensing, switches, and materials; which

have been extensively reviewed.4-26

1.2 Developing Trianionic Pincer and Pincer-Type Ligands

1.2.1 Pincer Ligands for High Oxidation State Metals

Traditional pincer and pincer-type ligands are monoanionic and arguably suited

for low oxidation state metals. Expanding the rich chemistry of these ligands to high

oxidation state metals (Mn+, n>3) for the purposes of catalysis and exploring

fundamental chemical transformations is problematic however. As illustrated in Figure

1-2, a pincer ligated complex may be accompanied by n-1 anionic ligands as well,

36

producing a coordinatively saturated metal ion; which can limit the applications

especially in catalysis due to the lack of an open coordination site for the substrate to

enter.

Avoiding a coordinately saturated metal ion requires a modification to the original

pincer ligand design. By incorporating the anionic ligands into the pincer ligand

framework, or more concisely, replacing the pendant’s neutral donor atoms with anionic

donors, the new trianionic pincer ligand liberates two additional coordination sites to

direct reactants to the metal center (Figure 1-2).

1.2.2 Versatility of the Trianionic Pincer and Pincer-type Ligand

Similar to traditional pincer and pincer-type ligands, the trianionic version is an

equally versatile ligand platform. Figure 1-3 depicts the current library of demonstrated

trianionic pincer27-43 and pincer-type44-58 ligands presented in the literature. Simple

modifications to the ligand design offer an easy approach to control the electronic and

steric properties of the ligand. Thus, a particular trianionic pincer/pincer-type ligand can

be engineered to alter the reactivity at a metal center or to induce completely new

reactivity. The result is a multifarious ligand class, with each trianionic pincer/pincer-type

ligand imparting a potentially novel reactivity to the metal center. As such, the rigid

meridional tridentate ligand class is ideally suited to explore a wide variety of high valent

metal catalysis and chemical transformations. Evidence for their multifarious nature is

the diverse applications that now include catalyzed aerobic oxidation,36 alkene

isomerization,28 alkene27 and alkyne31, 59 polymerization, nitrene45, 46 and carbene51

group transfer, and fundamental transformations such as oxygen-atom transfer,32

nitrogen-atom transfer,60 O2 activation,33 C−H bond activation,53 and disulfide

reduction.48

37

Work in the Veige group focuses on exploring the reactivity imparted to the metal

center by each trianionic pincer/pincer-type ligand. Our approach has been two-fold.

The first is designing trianionic pincer and pincer-type ligands that can potentially

improve a specific catalysis, and the second is exploratory by examining the reactivity

through fundamental transformations. Also contributing in this endeavor is Heyduk and

coworkers,45-52, 55, 58 who are investigating redox-active pincer-type ligands that feature

the trianionic property.

In achieving our goal to unearth the potential of trianionic pincer and pincer-type

ligands with high oxidation state metals, multiple ligand designs that accentuate novel

reactivity at the metal center are needed to explore a wide variety of chemical

transformation. This brief overview provides a glimpse of the (1) different reactions

influenced by trianionic pincer and pincer-type ligand design, and (2) current

approaches to create reative metal fragments. By analyzing the different subgroups of

pincer and pincer-type ligands, some interesting trends emerge. This introduction will

serve to to summarizing current work in this field and be a useful reference for

researchers to rationally design trianionic pincer and pincer-type ligands for specific

applications. As research with trianionic pincer and pincer-type ligands continue to

expand, we are confident that more applications and strategies for creating reactive

metal complexes featuring trianionic pincer and pincer-type ligand will be appended to

the growing list.

38

1.3 Rational Approaches to Create Reactive Complexes

Though trianionic pincer and pincer-type ligands are easily modified, the task of

designing a trianionic pincer and pincer-type ligand for a specific application can be

quite complicated. From a simple perspective, the selection of the anionic donor atoms,

the chelate ring size, and steric groups on the pendant arms must be compatible with

the desired application. For instance, the steric groups on the pendant arms provide a

valuable protection to avoid dimerization or higher order clusters..30 Here we provide a

more informed list on how trianionic pincer and pincer-type ligands may influences a

metal’s reactivity.

1. Confined meridional geometry with early transition metals 2. Restricted bite angle of pincer pendant arms 3. Open coordination site for catalysis 4. Insertion of unsaturated substrate into central pincer M-C bond 5. Electronically unsaturated metal centers 6. Constrained donor atom orientation 7. Support high oxidation state to promote inert bond activation 8. Redox active pincer ligands to mediate oxidation/reductions

1.3.1 Confined Medional Geometry with Early Transition Metals

Traditional pincer ligands offer little-to-no disturbance to many late transition

metal’s favored coordination geometry. More specifically, the square planar or

octahedral geometries, which are prolific among late d6 and d8 transitions metals,

naturally do not experience any significant distortion upon ligating with a meridional

tridentate ligand.

However, for early transition metals, the coordination geometries are more

diverse and include tetrahedral, trigonal bipyramidal, square pyramidal, and octahedral

geometries. For heavier transition metals, 7- and 8-coordinate complexes are not

39

uncommon.61 Coordinating a trianionic pincer ligand to early transition metals exerts a

preference on the coordination environment about the metal. For example, the

tetrahedral geometry, common for Group(IV) metals (Ti, Zr, and Hf), is obliged to adopt

a square planar/seesaw geometry upon ligating with a trianionic pincer/pincer-type

ligand (Figure 1-4). Additionally, similar restrictions on the ligand arrangement can be

imagined with 5- and 6-coordinate complexes.

The fixed coordindation geometry provided by a trianionic pincer/pincer-type

ligand presents a unique opportunity to investigate the role of ligand fluxionality62-66

within high valent metal catalysts. During a catalytic cycle, a set of coordinated ligands

may exchange positions, dissociate, or adopt different coordination geometries between

intermediates. Hemilabile ligands67-74 are an exemplary ligand class with late transitions

metals that promote ligand fluxionality to lower the energetic barrier between catalytic

intermediates. Thus, employing a rigid meridional tridentate ligand provides an

informative model to investigate the effect of ligand fluxionality by restricting the

movement of otherwise freely-moving ancillary ligands. The simple experiment design

directly assesses the role of ligand fluxionality in altering the energetic landscape for the

transformation between catalytic intermediates, and possibly may lead to enhanced

catalytic results. This thesis includes an investigation into alkyne metathesis presented

in Chapters 4 and 6 that explores the fluxionality of the ancillary ligand during catalysis.

1.3.2 Constrained Bite Angles of Trianionic Pincer Ligands

Controlling the bite angle of the pendant pincer arms is also a strategy that can

be used to generate reactive complexes ideal for catalysis (Figure 1-5). Ideally, the

pendant donor arms span 180°, but the pincer framework may prevent the donor atoms

from achieving this angle. The constrained bite angle depends on the linker spacing

40

within the pincer scaffold and the size of the coordinated metal ion. The bite angle

influences both the electronics of the metal center by the angular overlap75 of atomic

orbitals and the steric influence imparted by the pendant arm. The bite angle and its

consequence on catalytic reactivity has been well documented for bis-phosphine

ligands.76-84 Notable examples featuring trianionic pincer ligands are the NCN pincer

ligated hafnium complexes developed by Veige and coworkers that exhibit a

constrained pincer bite angle of ~140°.29, 30 The considerable difficulty in synthesizing

trianionic pincer/pincer-type complexes with acute bite-angles however has limited the

investigation into their reactivity.

1.3.3 Open Coordination Site

A significant challenge in catalysis is to provide a substrate with easy access to

the metal center, especially when a substrate is poorly coordinating or too large to

approach the metal center. A key motivation to use trianionic pincer ligands is to provide

an unhindered metal coordination site for the substrate to access. Figure 1-6 highlights

two possible scenarios where a trianionic pincer/pincer-type ligand opens up a metal’s

coordination environment. Case A: Trianionic pincer and pincer-type ligands confine

what would be a trigonal arrangement of anionic donors (X) into a T-shape geometry

creating a vacant coordination site. Case B: Replacing a macrocyclic tetradentate ligand

(e.g. salen, porphyrin, and corrole) with a tridentate pincer ligand exposes an additional

coordination site as well. Also, trianionic pincer ligands containing a central metal-

carbon bond impart a strong trans-influence that weakens the potential ligand bonding

at the new coordination site, thus enhancing the lability of the trans-coordination site.

41

1.3.4 Insertion of Unsaturated Substrate into Central Pincer M-C Bond

More specific to the chemistry of OCO trianionic pincer ligands, unsaturated

hydrocarbons such as alkynes insert into the pincer carbon-metal bond (Figure 1-7).34, 39

More recently, the Veige group has demonstrated that the Cα of a tungsten alkylidyne

reversibly inserts into a pincer C—W bond to form a tetraanionic pincer ligand.59 The

resulting complex displays remarkable activity as a catalyst for alkyne polymerization

(Figure 1-7).31, 59

1.3.5 Electronically Unsaturated Metal Centers

In addition to the metal center being coordinately unsaturated, trianionic pincer

and pincer-type ligands can produce electronically unsaturated metal complexes useful

for catalysis. The low electron count of early and high valent transition metals induces

an electrophilic metal center. Trianionic pincer and pincer-type ligands with few

available π-donating electrons can serve to starve the metal electronically. A notable

example is a trianionic NCN supported CrIV methide that is formally a 14-electron

complex and an active catalyst for ethylene polymerization.27

1.3.6 Constrained Donor Atom Orientation

Pincer and pincer-type ligands by nature of their rigid multidentate scaffold can

constrain the orientation of a lone pair of electrons on a sp2 hybridized donor atom (e.g.

amido) with respect to a metal center (Figure 1-8). For instance, nearly all trianionic

pincer ligands, containing an amido donor (NCN, NNN, ONO,SNS), lock the orientation

of the amido lone pair in a specific orientation with the metal ion (Figure 1-3). Hence,

the amido lone pair is unable to freely rotate often precluding the most suitable bonding

interaction with a metal center. As a result, a bonding combination between the metal

42

and the N-atom lone pair may provide interesting electronic50 and geometric44

consequences that may generate a reactive metal fragment.53, 54

1.3.7 Support High Oxidation State Metals

Trianionic pincer and pincer-type ligands by nature of their basic anionic donors

support high oxidation state metals similar to tetradentate porphyrin and corrole

ligands,85-88 but only occupy three coordination sites. The strongly reducing coordination

environment provided by the trianionic ligand facilitates the coordinated metal center

(Mn+) in activating X—X multiple bonds such as O2 or N2 by stabilizing the resulting

high oxidation state metal (M(n+m)+—X). However, the challenge in oxygenase catalysis

or dinitrogen functionalization is balancing the electron requirements for activating X—X

multiple bonds and then mediating X-atom transfer to an organic substrate. In contrast

to porphyrin and corrole ligand architectures, trianionic pincer and pincer-type ligands

are easily modified by selection of pendant donor groups to fine tune the electronic and

steric requirements to support high oxidation state metal ions for bond activation

processes.

1.3.8 Redox-active Pincer Ligands

Trianionic pincer-type ligands with continuous π-conjugation among the three

donor sites can undergo multiple oxidation state changes. These are defined as redox-

active pincer-type ligands. As a result of this conjugation, the trianionic pincer-type

ligand can access a dianionic and monoanionic oxidation state (Figure 1-9) in a similar

fashion to catecholate, semiquinolate, and quinone oxidation states.

A two electron redox cycle of a trianionic pincer-type ligand is a valuable

transformation to achieve multiple electron processes at a metal center. In particular,

when a metal center becomes inert to further oxidation, the pincer-type ligand may

43

provide two additional electrons to reduce the substrate within the metal coordination

sphere. Essentially, redox-active trianionic pincer ligands serve as an electron reservoir

for a metal center and can mediate oxidative and reductive transformations. The

research by Alan F. Heyduk45-52, 55, 58 focuses on incorporating redox chemistry typically

associated with late transition metals to the highly polarized metal-ligand bonds of d0

transition metals through the use of redox active pincer ligands.

Using redox-active trianionic pincer ligands are advantageous over traditional

bidentate catecholate-type ligands. Upon fully oxidizing bidentate catecholate-type

ligands to the quinone form, the neutral ligand weakly coordinates to the metal center

and readily dissociates.46 In constrast, a two electron oxidation of a trianionic pincer-

type ligand yields a monoanionic tridentate ligand that does not easily dissociate from

the metal center.

1.4 Designing Trianionic Pincer and Pincer-type Ligands for Applications in Aerobic Oxidation, C−H Bond Activation, and Alkyne Metathesis.

The work presented here in this thesis serves to demonstrate how trianionic

pincer and pincer-type ligands can be designed for specific applications. Chapters 2 and

4 focus on improving the catalyst design for aerobic oxidation and alkyne metathesis,

while Chapters 3 and 5 present an investigation into the fundamental transformations of

oxygen-atom transfer (OAT) and C−H bond activation. The introductions for each

chapter highlight the problems encountered in that field and how a rationally designed

trianionic pincer/pincer-type ligand may contribute to a solution. (Section 1.3)..

For the chromium-based aerobic oxidation catalyst presented in Chapter 2, the

appropriate selection of the donor atoms plays a crucial role in directing the metal’s

reactivity. The trianionic OCO ligand provides the appropriate electronic requirements to

44

mediate O2 activation and then transfer the oxygen atom to phosphines. Additionally, by

employing a central anionic carbon donor within a fixed meridional tridentate ligand, the

strong trans influence of the Cr−C bond creates a labile/open coordination site that

ensures O2 access to the metal center and avoids typical catalyst deactivation

pathways. Chapter 3 again utilizes the delicate electronic requirements provided by the

trianionic OCO pincer ligand to investigate the oxygen-atom transfer reaction from high

valent chromium-oxo complexes.

Chapter 4 focuses on improving alkyne metathesis catalysts by using a trianionic

ONO pincer-type ligand. The basic strategy is that the trianionic pincer/pincer-type

ligands confine the otherwise fluxional ancillary ligands into a T-shape geometry and

provides an open coordination site for substrate to enter. As intended, a swift

cycloaddition of sterically large alkynes occurs, but the electronic features of the ONO

ligand in addition to the poor steric pressure from the pendant arm prevent a necessary

retro-[2+2]-cycloaddition for further alkyne metathesis from occurring.

A unique electronic feature of the trianionic ONO pincer-type ligand is the

constrained orientation of an amido lone pair of electrons. The rigid ligand framework

constrains the nitrogen lone pair to align colinearly with the W−C π-bond, creating an

inorganic version of an enamine. In Chapter 5, this unique bonding interaction is used to

enhance the nucleophilicity of the W−C π-bond and promote an unusual C−H bond

activation via releasing isobutylene.

45

Figure 1- 1. The original PCP pincer ligand (A) by Shaw,1 and PNP pincer-type ligand (B) by Ozerov.2

Figure 1- 2. A coordinately-saturated high valent metal (M) featuring a pincer ligand A and a low-coordinate high valent metal with a trianionic pincer ligand B.

46

Figure 1- 3. Current library of demonstrated trianionic pincer A,27-30 B{(tBu, H),31-38 (tBu,

tBu),39, 40 (tBu, Me),41, 42 and (Ad, Me)42} and C43 ligands; and pincer-type D,44 E{(SiMe3, H)44 and (iPr,OMe)45-47}, F,46, 48-52, 58 G,53, 54 H,55 I,56 and J57 ligands.

47

Figure 1- 4. Coordination geometry changes upon imposing a trianionic pincer ligand on a tetrahedral metal center.

Figure 1- 5. Bite angles and linker spacing.

Figure 1- 6. Creating open coordination sites. A) Confining arrangement of donor ligand. B) Replacing tetradentate macrocycle ligand with tridentate pincer.

48

Figure 1- 7. Insertion into the OCO pincer C-M bond. A) Insertion of unsaturated substrate. B) Insertion of an alkylidyne α-carbon into OCO pincer C-W bond to form a highly active alkyne polymerization catalyst featuring a tetraanionic pincer ligand.

Figure 1- 8. Constrained amido orientation using trianionic pincer-type ligand.

Figure 1- 9. Potential redox states of a non-innocent pincer-type ligand.

49

CHAPTER 2 AEROBIC OXIDATION CATALYST FEATURING BY A TRIANIONIC PINCER CrIII/CrV

COUPLE AVOIDING COMMON CATALYST DEACTIVATION PATHWAYS

2.1 Introduction

The vast majority of oxidation reactions are performed to make commercial

chemicals from crude oil89-91. Even after crude refinement, multiple selective oxidation

steps are required to transform the starting materials into useful reagents for further

upstream derivation and application.91-93

Oxidation reactions present a significant challenge and danger to accomplish on

an industrial scale.93 The oxidant must be both easily available and powerful, while

ensuring security. Dioxygen, O2, is an ideal oxidant source due to its atom-economy,

selectivity, environmental, and monetary considerations.94, 95 Though the direct

oxidation of organic substrates with O2 is thermodynamically favorable, the reaction is

spin forbidden creating a high kinetic barrier.96, 97 As result, autooxidation reactions

require heating at high temperatures and are inherently unselective.

Transition metal complexes94, 95, 98 can selectively mediate several types of

oxidation reactions using dioxygen as the oxidant source, avoiding the high kinetic

barrier for the spin forbidden reaction. A simple classification of oxidation reactions are

oxidase, monooxygenase, and dioxygenase. Oxidase99-110 reactions oxidize the

substrate without incorporating oxygen atom into the product, whereas

Reprinted/adapted with permission from M. O'Reilly, J. M. Falkowski, V. Ramachandran, M. Pati, K. A. Abboud, N. S. Dalal, T. G. Gray and A. S. Veige, Inorg. Chem., 2009, 48, 10901-10903. Copyright 2009

American Chemical Society.

Reprinted/adapted with permission from M. E. O'Reilly, T. J. Del Castillo, J. M. Falkowski, V.

Ramachandran, M. Pati, M. C. Correia, K. A. Abboud, N. S. Dalal, D. E. Richardson and A. S. Veige, J. Am. Chem. Soc., 2011, 133, 13661-13673. Copyright 20011 American Chemical Society.

50

monooxygenase94, 111-116 and dioxygenase94, 112, 117 deliver one and both oxygen atoms

to the substrate, respectively.

Homogeneous transition metal complexes excel at mediating oxygen-atom

transfer118-122 and catalyze oxidation reactions using a mild O-atom source,94, 95, 98 but

relatively few utilize molecular oxygen.98, 117, 123-135 Aerobic oxygenase catalysts face a

unique challenge.136 The ligand design must appropriately balance the electronic

requirements needed by the metal center. A metal catalyst must be reducing enough to

activate O2, yet the resulting metal-oxo complex must be sufficiently oxidizing to transfer

the O-atom to substrate.137, 138 For practical applications, maximizing the rate of O2

cleavage is important, but not at the cost of creating inert metal-oxo intermediates.139

Oxygenase catalysis presents a second substantial difficulty, in addition to the

sensitive electronic requirements. The supporting ligand must avoid catalyst

deactivation pathways presented in Figure 2-1. Product inhibition is the most salient

deactivation mechanism, where the oxidized substrate binds to the catalyst to produce a

coordinately saturated metal ion. A second deactivation mechanism is the

comproportionation of Mn+ and M(n+2)+=O species to yield thermodynamically stable

dinuclear μ-oxo complexes that do not partipate in catalytic turnover.122, 137, 140-142 M-O-

M species are known for iron,135, 143-153 chromium,141, 154-160 and manganese142, 161-175

oxidation catalysts. Of that group, formation of (P)FeIII-O-FeIII(P) (P = porphyrin)176

permanently deactivate the catalyst,135, 143-145 whereas Cr-O-Cr and Mn-O-Mn

complexes form reversibly during catalytic turnover. In both cases, the product inhibition

and μ-oxo dimer formation impede the re-oxidation of the catalyst by the oxidant.

51

Oxygenase catalysts featuring tetradentate ancillary ligands (e.g. porphyrin,

corrole, and salen) are susceptible to catalyst deactivation by product inhibition. An

exemplary system by Gray and co-workers128 features a corrole-ligated85, 177-179

CrIII/CrVO cycle. This system catalyzes the aerobic oxidation of triphenylphosphine

(PPh3), but product inhibition and catalyst decomposition limit the turnover number

(TON; mol product/mol catalyst) to 33. Similary, the catalytic oxidation of thiophenol to

diphenylsulfide yields a TON of 55 and a turnover frequency of ~3 h-1 (TOF; mol

product/mol catalyst 3 h).

Our approach to improve the overall catalyst performance is to replace

tetradentate ligands with a tridentate trianionc pincer ligand. Similar to corroles,

trianionic pincer ligands can stabilize high oxidation states needed for dioxygen

activation,85 yet only bind three sites. We envisioned that a catalyst containing more

open or labile sites will exhibit improved catalytic properties. More specifically, the

trianionic OCO pincer ligand purposely exploits the Cr-C bond trans-influence to

weaken bonds to the newly created coordination site (Figure 2-2).

Here, we present the synthesis of an aerobic oxidation catalyst featuring a

trianionic OCO3- pincer ligand supported chromium complex. The catalyst displays

remarkable activity for the oxidation of PPh3. Moreover, we conclusively demonstrate

that the trianionic pincer ligand avoids typical deactivation pathways enabling

remarkably swift O2 activation.

2.2 Results and Discussion

2.2.1 Synthesis of [tBuOCO]HK2•1.5 THF (1) and [tBuOCO]CrIII(THF)3 (2)

We sought a mild metalation strategy that combines double salt metathesis with

C-H bond activation. Thus, we synthesized the dipotassium derivative [tBuOCO]HK2•1.5

52

THF (1) by treating [tBuOCO]H3 with potassium hydride (KH) in THF (Figure 2-3). Upon

the addition of 1 to MeCrCl2(THF)3 in THF, the solution instantly darkens from lime

green to dark green (Figure 2-4). After 5 h, solvent removal provides a green solid. The

product is extracted into toluene, and KCl is removed by filtration. After removing the

toluene in vacuo, the residue is dissolved in minimal THF and cooled to -35° C to induce

crystallization and produce analytically pure 2 in 44% yield.

The 1H NMR spectrum of 2 reveals paramagnetically shifted and broadened

resonances. The signals appear at 8.20 (ν1/2= 518), 1.45 (ν1/ 2=1035; tBu),-7.44 (ν1/2

=645), -13.23 (ν1/2 = 750), and -22.71 (ν1/2 = 2520) ppm. No resonances are observed in

the 13C{1H} NMR spectrum of 2. Although the 1H NMR spectrum is not useful for

confirming the identity of 2, there is enough information available (location of

resonances and ν1/2) to determine if subsequent reactions lead to new chromium-

containing products.

Single crystals grow by cooling a concentrated solution of 2 in THF to -35 °C.

Exemplifying the reactivity of 2 toward O2, crystals of 2 immersed in Paratone 8277 oil

(Exxon) darken within minutes and must be cooled with dry ice prior to crystal selection

for X-ray analysis. Figure 2-5 depicts the molecular structure of 2, which consists of a

distorted octahedral CrIII ion coordinated by the OCO3- pincer and three THF ligands.

The mutually trans-THF ligands and two lattice THF molecules (not shown) are

disordered. The OCO pincer ligand adopts a pseudo C2-symmetric orientation. A strong

trans influence from the Cr-C1 bond (d(Cr1-C1)= 2.011(3) Å) causes a 0.14 Å

elongation in the Cr1-O3 bond length (d(Cr1-O3) = 2.1939(18) Å) compared to Cr1-O4

(d(Cr1-O4) = 2.0624(18) Å) and Cr1-O5 (d(Cr1-O5) = 2.0566(18) Å). As expected,

53

shorter bonds form between the CrIII ion and the alkoxide attachments (d(Cr1-

O1)=1.9227(17) Å and d(Cr1-O2)=1.9248(17) Å).

2.2.2 Synthesis of [tBuOCO]Cr(≡O)(THF) (3)

When treating 2 with an excess of O2 (1 atm) in toluene, the CrVO complex

[tBuOCO]CrV(≡O)(THF) (3) forms immediately (Figure 2-6), and the solution color

changes from bright green to red-brown. The 1H NMR spectrum of 3 exhibits several

broad paramagnetically shifted resonances at 11.4 (ν1/2= 117), 9.0 (ν1/2= 201), 4.3 (ν1/2=

225), 2.4 (ν1/2= 363), and 1.2 (ν1/2= 45) ppm. The addition of THF to the NMR tube

causes the signal at 1.2 ppm to grow and is attributable to a bound THF capable of

rapid exchange with free THF. In the solid state, 3 is brown, and the CrV≡O stretch

appears as a strong absorption at 988 cm-1 and shifts to 943 cm-1 for the CrV≡18O

derivative.36, 57, 180-189

An EPR spectrum (Appendix) of a 10 mmol solution of 3 in toluene exhibits a

strong resonance at giso=1.9770. The central absorption corresponds to the S=1/2

electron spin transition from the 52Cr isotope (I=0), and four weak satellite peaks,

spaced 19 G (1.9 mT) apart, arise from hyperfine splitting with the 53Cr (I=3/2) nucleus,

consistent with a CrV ion.190 The UV-vis spectrum of 3 reveals ligand-to-metal charge

transfer absorptions in the UV region at 250 nm and at 285 nm and a weak d-d

transition at 500 nm.

Figure 2-7 shows the molecular structure of the CrV≡O complex 3 obtained by

single-crystal X-ray analysis and confirms the presence of an oxo ligand. Complex 3

consists of a CrV ion in a distorted trigonal bypyramidal (tbp) geometry that consists of

the OCO trianionic pincer, the oxo, and a THF molecule in one of the axial positions.

The oxo ligand occupies an equatorial position with a typical Cr-O bond length of

54

1.5683(18) Å.36, 57, 180-189 The C1-Cr-O3 angle of 165.27(8)° is significantly distorted

from linearity, caused in part by the strain of the terphenyl ligand and the short Cr≡O

bond. The equatorial atoms create angles of 116.73(9)°, 115.82(9)°, and 126.89(8)°,

signifying a coordination geometry closer to tbp than to square pyramidal. This is the

first example of a tbp Cr(V)-oxo complex.36, 57, 180-189

Spin-unrestricted density-functional theory calculations were performed on 3’, an

analogue of 3 having methyl groups in place of t-butyl. Full geometry optimization

converged on a potential-energy minimum, as confirmed by a harmonic vibrational

frequency calculation. The optimized structure captures the trigonal bipyramidal

geometry about chromium. The computed bond distances agree well with

crystallographic values: the calculated (experimental) chromium-oxo oxygen bond

length is 1.569 Å (1.5683(18) Å); the Cr-Opincer distances are 1.819 Å (1.8166(17) Å)

and 1.815 Å (1.8098(17) Å), and that to the THF oxygen atom is 2.243 Å (2.1781(17)

Å). The calculated Cr-Cpincer bond length is 1.992 Å (2.009(2) Å, experimental). The

calculated g factor agrees well with the experimental data (1.9970 exptl/1.969 calcd).

The short distance between chromium and the oxo ligand suggests multiple-bond

character, and the Wiberg bond order is 2.15.191 Corresponding Cr-O bond orders to the

pincer ligand oxygen atoms are 1.00 and 1.04. The THF ligand is weakly held, with a

Cr-O bond order of 0.27.

The unpaired electron (S=1/2) resides in an orbital of mixed Cr-pincer ligand

parentage (Figure 2-8). The highest occupied and lowest unoccupied Kohn-Sham

orbitals are majority-spin (R) functions. A Mulliken population analysis192 assigns 21% of

the R-HOMO (HOMO = highest occupied molecular orbital) density to Cr and 79% to

55

the anionic pincer. The R-LUMO (LUMO=lowest unoccupied molecular orbital) is

primarily a Cr-O π* combination, with 62% Cr, 26% oxo, 2.6% pincer ligand, and 9.4%

THF character. The Cr-O π* orbital is a reasonable point of attack by external

nucleophiles such as PPh3.

2.2.3 Aerobic Oxidation of PPh3 Catalyzed by [tBuOCO]Cr(≡O)(THF) (2)

Indeed, in the presence of 1 atm of O2, the reduced CrIII complex 2 catalytically

oxidizes PPh3 to O=PPh3 with a TON of 195 (Figure 2- 9). The catalysis works on a bulk

scale. Within 3 h, 0.68 g of O=PPh3 (2.44 mmol) forms with only 8 mg (0.0125 mmol) of

the catalyst. In an NMR tube reaction, consumption of 10 equiv of PPh3 occurs before

obtaining the first spectrum (∼5 min), which correlates to a minimum turnover frequency

of 100 h-1. In the presence of excess O2, after consumption of all of the PPh3, the red-

brown color of the CrVO persists, but upon reintroduction of more substrate, the

catalysis resumes. Catalytic turnover with 2 also occurs when air is the source of O2.

To confirm a dioxygenase model, treating 2 with a stoichiometric amount of 18O2

and PPh3 provides >98% 18O≡PPh3 quantitatively. During the catalytic reaction, a broad

resonance appears in the 31P{1H} NMR spectrum at 26.18 ppm, and as more product

builds, the resonance migrates to the position of free O≡PPh3 at 30.11 ppm, This is

attributable to a phosphineoxide bound CrIII complex in exchange with free O≡PPh3.

2.2.4 Prelude to the Kinetic Investigation into the Mechanism O2 Activation by 2

The trianionic OCO pincer ligand creates a sufficiently reducing environment

within complex 2 that is needed to activate O2 to form a high oxidation state CrV≡O

complex. Complex 3 is thermodynamically competent to transfer the oxo ligand to PPh3,

but is unable to transfer the oxygen atom to other substrates, such as sulfides and

56

olefins. The catalytic aerobic oxidation of PPh3 by complex 2 is impressive (TON =195)

relative to the corrole system (TON = 33), suggesting that the additional pincer ligand

may be responsible. However, a complete kinetic investigation is required to probe the

mechanism of O2 activation and possible catalyst deactivation pathways that would

inhibit reoxidation of the catalyst. Presented in the next sectionis that study.

2.2.5 UV-vis Measurements for the Rate of O2 Activation by 2

A color change from green to reddish brown occurs when 2 reacts with O2 to

form the CrV(O) complex [tBuOCO]CrV(O)(THF) (3). UV-visible spectrophotometry is a

suitable method for studying the reaction of [tBuOCO]CrIII(THF)3 (2) with O2. Figure 2-10

depicts the time-dependent changes in absorption upon exposure of a 1 x10-4 M

solution of 1 to 1.66 x10-3 M O2. Controlling the O2 concentration requires injection of a

known quantity of an O2-saturated THF solution (9.90 x10-3 M at 25 °C).193 Changes in

the UV-vis spectrum displays isosbestic points at 318 and 385 nm, and measuring the

changes in the absorption at 341 nm generates a plot of the concentration of 2 vs time

(Figure 2-11).

The complete oxidation of 2 occurs within approximately three minutes. Plots of

concentration vs time reveal a linear segment within the first ~80% of the reaction,

followed by a gradual curvature in the remainder of the reaction until completion (Figure

2-11). The plot of [2] vs time does not fit first-order or second-order kinetics.

2.2.6 O2 Cleavage Rate Dependence on [2], [O2], [THF], and Temperature

Solutions of 2, between 0.55 – 1.65 (x10-4) M, were allowed to react with a

known quantity of O2 to produce the concentration versus time plots in Figure 2-12. The

initial rates can be determined from the initial values of Δ[2]/Δt. Figure 2-13 shows the

57

linear dependence of the average rate, Δ[2]/Δt, on the [2]. The linear plot indicates a

first-order dependence in [2].

Determination of the order in O2 requires addition of known quantities of O2-

saturated THF solutions to 2. The concentration of O2 in a saturated THF solution is

9.90 x10-3 M.193 Four independent reactions that vary in O2 concentration from 1.66 to

6.66 mM (Figure 2-14) result in a linear plot of initial rate Δ[2]/Δt versus [O2] (Figure 2-

15). The linear dependence indicates a first-order O2 relationship.

The oxidation of 2 with O2 in non-coordinating solvents proceeds rapidly. The

complete oxidation of 2 in hexanes occurs within ~3 s, thus preventing the

measurement of a reliable reaction rate. Introduction of THF between 50% and 100%

(v/v) into a hexanes solution of 2 slows the reaction enough to permit the determination

of Δ[2]/Δt, and thus the solvents role. Plotting the -Δ[2]/Δt vs XTHF yields a parabolic

curve (Figure 3- 16) consistent with an inverse order in [THF], but the changes in the

dielectric constant of the solvent mixture could produce a similar effect. Most likely, the

parabolic relation between -Δ[2]/Δt vs THF results from the mechanistic dissociation of

one or two THF molecules in addition to dielectric constant changes.

Lowering the temperature of the reaction provides more insight into the unusual

non-first-order kinetic profile by resolving the shape of the decay plot of [2] vs time.

Figure 2-17 depicts the [2] vs time plot at 40, 20, 10, and 0 °C. The kinetic trial at 0 °C

yields a sigmoidal plot of [2] vs time, which is consistent with an autocatalytic

mechanism.

If the oxidation of 2 is catalyzed by 3, then increasing the initial [3] should

accelerate O2 activation. Figure 3- 18 and Figure 3- 19 depict an increasing rate of

58

oxidation of 2 with an increasing initial [3] and confirms the product-catalyzed oxidation

of 2.

We propose that the oxidation of 1 by O2 occurs via an autocatalytic mechanism.

Initially, the oxidation of 1 to 2 is slow. However, upon accumulation of 2 in solution, a

faster autocatalytic pathway, in which the product 2 catalyzes the oxidation of 1 to 2,

becomes predominant (vide infra).

2.2.7 Characterization of the Autocatalytic Intermediate: the Chromium(IV) μ-oxo Dimer {[tBuOCO]CrIV(THF)}2(μ-O) (4)

How does [tBuOCO]Cr(O)(THF) (3) catalyze O2 activation by 2? One possibility

is the formation of a CrIV-O-CrIV adduct that reacts more rapidly than 2 with O2. An

attempt to form the adduct by stoichiometric addition of 3 to 2 in THF failed. Adding a

green solution of 2 and a red solution of 3 in THF yields a brown solution. The 1H NMR

spectrum of the reaction mixture reveals only signals attributable to 2 and 3, and at -35

°C, only green crystals of 2 precipitate. When 2 is oxidized to 3 in toluene, however, a

bright purple intermediate species forms and then converts to the deep red color of 3.

Considering this observation, stoichiometric addition of 2 to 3 in toluene indeed yields a

bright purple solution consisting of a small concentration of starting reagents and the

major product, postulated to be the dimer {[tBuOCO]CrIV(THF)}2(μ-O) (4) (Figure 2-20).

The 1H NMR spectrum of the reaction mixture (C6D6) contains new paramagnetic

resonances distinct from 2 and 3 at 28.70 (ν1/2 = 570 Hz), 16.89 (ν1/2 = 675 Hz), and -

30.57 (ν1/2 = 540 Hz) ppm. The characteristic 1H NMR signals for 4 disappear upon

addition of THF indicating an equilibrium exists between CrIII (2) and CrV(O) (3) and 4.

The formation of 4 evidently requires a non-coordinating solvent.

59

Purple hexagonal-plate single crystals of 4 form at -35 °C from concentrated

diethyl ether solutions of the mixture. Since 2 is present in the equilibrium mixture,

several crystals of 2 also deposit, as a result isolation of pure 4, except as a single

crystal is not possible. Subjecting the purple crystals to a single crystal X-ray analysis

experiment provides the molecular structure of 4. In the solid state, complex 4 is C2

symmetric and contains two [tBuOCO]Cr fragments bridged by oxygen (Figure 2-21).

The asymmetric unit consists of one half of the molecule and the O atom resides on a

C2 axis that generates the second half of the molecule, thus rendering the Cr ions

equidistant from the µ-oxo by 1.7497(6) Å and creates a 158.69(14)° Cr-O-Cr angle

across the bridge. As a consequence, the Cr-O bond lengths do not provide insight to

ascertain the Cr oxidation state. The geometry of the CrIV ion is distorted trigonal

bipyramidal (tbp) with an Addison parameter of τ = 0.77.194 Each Cr coordinates to a

trianionic OCO3- pincer, the µ-oxo bridge, and a THF molecule. The equatorial sites

consist of the alkoxide attachments, and the µ-oxo bridge, whereas the Cr-Cpincer bond

and THF occupy axial positions. Consistent with a higher oxidation state CrIV ion, the

Cr-Opincer (d(Cr1Opincer)avg = 1.8046(2) Å) bonds are shorter than in 2 by 0.113(3) Å,

and the Cr-Cpincer (d(Cr1C1) = 1.983(2) Å) is shorter by 0.028(4) Å.

An interesting structural feature is the ~82° twist between the two Cr ion

coordination environments. Figure 12 provides an electronic argument for the

approximate 90° twist and the near linearity of the Cr-O-Cr bonds. The sp hybridized

oxygen forms two σ bonds between the Cr ions. The additional four electrons on oxygen

π-donate into Cr d-orbitals. From Figure 2-22, assigning the Cpincer-Cr-THF as the z-axis

and Cr-O-Cr as the x-axis, the dxz and dxy are two available d-orbitals with appropriate

60

symmetry for accepting π-electrons from oxygen. Since the dxy orbital participates in

bonding with the two-alkoxide ligands, it is high in energy and relatively inaccessible. In

contrast, the dxz orbital is a low-lying energy orbital available for π-bonding with oxygen.

The most favorable π-donating interaction is into the dxz of each respective Cr ion, thus

adopting a ~90° twist to accommodate the two orthogonal lone pairs on the oxygen.

Figure 12 also depicts a ligand field splitting diagram that corresponds to this bonding

and electronic interaction. Assigning two d-electrons to the dxz and dyz orbitals of each

Cr center allows for the maximum number of unpaired electrons. A similar assignment

was made for an isoelectronic VIII-O-VIII dimer.195 The resulting d2 configuration for

each Cr ion supports an oxidation state of +4 for each ion. Despite the smaller CrIV ion,

the Cr-THF distance is 0.043(2) Å longer than that in 2, due to the stronger trans

influence of the Cr-Cpincer bond in 4, and a more congested coordination sphere due to

the mutually adjacent [tBuOCO]CrIV fragment.

2.2.8 Electron Paramagnetic Resonance Measurements of 4

Though the above X-ray and NMR results indicated that 4 is a new paramagnetic

Cr-O-Cr dimer, additional data were needed to directly characterize its electronic

structure. Figure 2-23 depicts the 240 GHz EPR spectra of a powder sample of 4. The

resonances indicate the presence of Cr(III) (weak signals) and a S = 2 dimer (4).

Reducing the temperature lowers the thermal Boltzmann population of electronic states,

and the resonances intensify. The program SPIN196 simulates the EPR spectrum at 4.5

K, and, for comparison, Figure 2-24 depicts both the simulated spectrum and

experimental data. Simulating the CrIV-O-CrIV species alone did not reproduce all the

resonances. Considering that 5 is in equilibrium with the mononuclear complexes 2 and

3 (Scheme 3), complex 4 was included in the simulation. However, complex 3 is difficult

61

to distinguish among resonances 5, 6, and 7 of Figure 2-24. The approximate amount of

complex 3 is less than 10% and therefore is not included in the simulation.

The resonances arise from the predominant (~70 %) S = 2 (CrIV-O-CrIV, 4) and

the minor component S = 1.5 (CrIII, 2). For the dinuclear complex 4, the two

paramagnetic fragments, with spins S1 and S2, can be described by the following

standard Spin Hamiltonian (Equation 2- 1),197-199

H =

222

213

)1(yxz SSE

SSSDSgHSJS H hyp (2- 1)

where J is the spin-exchange coupling constant, β is the Bohr magneton, g is the

Lande g-tensor, S is the total spin = S1 + S2; with components Sx, Sy and Sz, with z

being taken to be the direction along which the Zeeman field H is applied. Hhyp is the

electron-nuclear hyperfine interaction. The EPR spectrum reveals no hyperfine splitting

from the 53Cr isotope (9.5% abundant) with I = 3/2, so Hhyp can be omitted. The Spin

Hamiltonian parameters for S = 2 (CrIV-O-CrIV) are giso = 1.976, D =2400 G (Gauss), and

E = 750 G; and for S = 1.5 (CrIII) are giso = 1.976, D =10500 G (Gauss), and E = 3000 G

(Figure 14). The good fit of the simulation to the experimental spectrum permits

conclusive assignment of a +4 (d2) oxidation state for each Cr ion in 4. The individual

simulations for the CrIV-O-CrIV dimer and CrIII species are in the Appendix.

Figure 2-25 depicts a simulated 240 GHz energy level diagram of 2 (top panel)

and 4 (bottom panel) at 4.5 K. The vertical red bars mark the possible spin transitions

while the dotted lines point to the relevant peaks corresponding to molecular z-

orientation (z1 and z1’; z2 and z2’) in the simulated spectrum (center panel). The

asterisks denote the spin forbidden transitions.

62

2.2.9 Proposed Mechanism of O2 Activation

The reaction orders in [2], [O2], [3] and [THF] are consistent with the proposed

mechanism in Figure 2-26. During the initial stages of the reaction, the oxidation of 2

follows pathway A. The first step involves the dissociation of THF followed by O2

coordination to generate an intermediate species 2b. A single crystal X-ray structural

analysis of 2 suggests preferential dissociation of the THF trans to the Cr-Cpincer bond.

Inspection of the three Cr-THF bond lengths in 2 reveals the Cr-THFtrans (Cr1-O3 =

2.1939(18) Å) is ~ 0.14 Å longer than the two Cr-THFcis bonds (Cr1-O4 = 2.0624(18) Å

and Cr1-O5 = 2.0566(18) Å).

It is proposed that intermediate species 2b then reacts with 2 to generate a

second intermediate 2c before the O-O bond cleaves in the final step to yield 3. The

first-order dependence on [2] suggests the formation of 2b is the rate-determining step.

The high rate of oxidation precludes definitive assignment for the structure of

intermediates 2b and 2c. There are precedents for both end-on and side-on dioxygen-

chromium complexes.200-213

To be autocatalytic, a product-catalyzed pathway has to accelerate the formation

of 2b to increase the overall rate of the oxidation. Pathway B in Figure 2-26 illustrates

the product-catalyzed oxidation of 2. The formation of dimer 4 from 3 and 2 provides a

low-coordinate species that allows O2 access to the metal. The coordination of O2 to 5

results in the cleavage of the dimer to yield 2b and regenerates 3, which can re-enter

Pathway B. Pathway B is faster than pathway A because pathway A requires the slow

dissociation of THF prior to O2 coordination thus, autocatalytic conditions establish as

the concentration of 3 increases.

63

2.2.10 Kinetic Simulations

Strong evidence exists for the autocatalytic pathway B; for example, the shape of

the decay plots for the oxidation of 2 and foremost, the isolation and characterization of

dimer 4. However, during the oxidation of 2, dimer 4 is a steady state intermediate and

no experiment directly probes its formation. To complement the kinetic studies and to

support the proposed mechanism, numerical simulations were performed using the

computer program Kinetica. Equation 2- 2 describes the stoichiometric reaction

between 2 and O2 to provide 3, and Equations 2- 3 to 2-7 show the elementary reaction

steps from the proposed mechanism used in the simulations.

(2- 2)

(2- 3)

(2- 4)

(2- 5)

(2- 6)

(2- 7)

The elementary steps involving the addition or dissociation of THF are excluded

from the simulation. Since [O2] is in ten-fold excess, k1[O2] and k5[O2] are pseudo first-

order rate constants.

64

(2-8)

Equation 2-8 is the derived rate law for the set of Equations 2- (3-7) and the

proposed mechanism in Figure 2-26. At each concentration of 2 (0.55, 1.10, and 1.65

(x10-4) M) and O2 (1.66, 3.33, 4.99, and 6.66 (x10-3) M), three independent

concentration versus time profiles were recorded. Using average concentration versus

time data from the kinetic trials at each initial [2] and [O2], the conjugate gradient

optimization provides the best fit rate constants. The rate constants k2 and k3 rate

constants are indeterminable since they occur after the rate determining step, and their

values were fixed > 1.00 x106. The averaged estimated rate constants (k1, k4, k-4/k5) are

2.6(±0.6) s-1, 396.8(±0.7) M-1s-1, and 6.0(±2.3) x10-3, respectively (THF, 25°C). Data

fitting only permits the calculation of k-4/k5 as a ratio for the proposed mechanism. The

rate constants were used to simulate individual concentration versus time profiles for

kinetic runs that vary in the initial concentration of 2 and O2. Figure 2-27 and Figure 2-

28 illustrate the simulated kinetic profile, and the experimental data, for concentration

versus time profiles of 2 at different initial concentrations of 2 and O2. The simulated

kinetic profiles match the profiles obtained experimentally.

For the kinetic profiles varying in temperature, new rate constants were

calculated for each temperature and are presented in Table 2-1. Figure 2-29 depicts

the simulated and experimental concentration versus time profile for the oxidation of 2

with O2 at different temperatures. An important feature exhibited in this set of data is the

curvature of the profile at early reaction times. In particular, at 0 °C the reaction slows

enough to detect the onset of the autocatalytic pathway B. The simulated data fits the

65

experimental data well during this stage of the reaction. At 40 °C, the reaction is too

fast (only three data points within 10 sec, >90 % conversion) to obtain reliable data.

2.2.11 Product Inhibition Studies

Product inhibition occurs when a strong coordinating ligand/product binds to the

metal center preventing further O2 activation. In the case of Cr-corroles, the product

OPPh3 binds to the two axial positions thus inhibiting further oxidation.128 To probe a

similar deaction pathway for complex 2, the rate of O2 activation was measured with

increasing [OPPh3]. With higher concentration of OPPh3, the rate of O2 activation is

expected to decelerate or stop completely. Uniquely for the trianionic pincer complex 2,

the opposite occurs; an increasing concentration of OPPh3 accelerates O2 activation.

Figure 2-30 contains a plot of the change in concentration of 2 versus time during the

O2 oxidation in the presence varying [OPPh3] (0 to 0.10 M). The rate of oxidation of 2

accelerates upon addition of OPPh3, and at 1000 equivalents of OPPh3 (0.10 M) the

rate cannot be measured within our experimental setup.

2.2.12 Isolation of a Catalytic Intermediate [tBuOCO]Cr(OPPh3)2 (5)

The unusual rate acceleration caused by the addition of OPPh3 prompts us to

isolate the reactive species prior to the addition of O2. Treating a solution of 2 with five-

fold excess OPPh3, forms a deep green solution (Figure 2-31). Single crystals of the

resulting complex form in supersaturated CH2Cl2 solutions, and an X-ray analysis

provides the molecular structure of complex 5 (Figure 2-32).

Complex [tBuOCO]CrIII(OPPh3)2 (5) is square-pyramidal with C2v symmetry in

which the pincer-carbon atom is apical and the two Cr-O alkoxides and O=PPh3 fulfill

the basal positions. The pyramidal base is distorted along the trans-O=PPh3 ligands

(O3-Cr-O4 = 157.38(5)°) but nearly linear across the trans-alkoxides (O1-Cr-O2 =

66

175.28(5)°). The defining feature of 5 is the open coordination site opposite the Cr-C1

bond. Consequently, of the three compounds within this study, 5 presents the shortest

Cr-Cpincer bond of 1.9761(17) Å. Hence, the pincer architecture exploits the strong trans-

effect of the chromium-carbon bond to a labile coordination site. By weakening possible

dative bonding interaction, complex 5 obviates catalyst deactivation by product inhibition

and provides an accessible binding site for O2 to facilitate activation.

The role of OPPh3 in facilitating O2 activation by 2 is similar to the role of complex

3 in the formation of the dimer 4. Excess OPPh3 provides the coordinatively unsaturated

complex [tBuOCO]CrIII(OPPh3)2 (5) (Scheme 5). The solid state structure36 indicates

only two OPPh3 ligands coordinating to the CrIII ion despite excess OPPh3 being present

in solution. Complex 5 provides an unobstructed coordination site for O2 coordination

allowing for faster oxidation.

The increased rate of O2 activation by adding OPPh3 suggests an equilibrium

between 2 and 5 exists in THF. As more OPPh3 is added, the equilibrium shifts towards

5 until it is the dominant species. Attempts to directly monitor the rate of O2 activation

with 5 failed because the reaction is too fast.

2.2.13 Cyclic Voltametry of 2, 4, and 5

Both dimer 4 and complex 5 have an open coordination site compared to 2. As a

consequence, the rate of O2 activation is faster for 4 and 5. However, the increased

oxidation rate may be a consequence of a more reducing metal ion caused by the

coordination of 3 in the dimer 4 and OPPh3 in complex 5. To examine this possibility,

complexes 2, 4, and 5 were subjected to cyclic voltammetry experiments to determine

their electrode potentials. Complexes 2, 4, and 5 display irreversible first oxidation

peaks at 0.732 V, 0.298 V, and 0.012 V respectively. Though the lower oxidation

67

potentials appear to correlate with the faster rate of O2 activation, the irreversibility of

the CV spectra prevents a definitive conclusion from being drawn.

2.3 Conclusions

The trianionic OCO pincer ligand offers a balanced electronic environment for

oxygenase catalysis. Consistent with our initial presumption, trianionic pincer ligands

support high-oxidation state metals. This is most evident in the activation of O2 to form

complex 3. Additionally, the NCN trianionic pincer chromium(III) complex activates

dioxygen.28 Yet, the trianionic OCO ligand is not too reducing, or the resulting CrV≡O is

not too stabilized to prevent OAT to PPh3, as in the case of [NCN]CrV≡O.28 However,

the inability of complex 2 to aerobically oxidize sulfides and olefins illustrates the

delicate balance, and further work to fine tune the electronic properties is needed to

expand the substrate scope. Even so, complex 2 is a suitable model system to

understand the advantages that a trianionic pincer ligand can bring to oxygenase

catalysis.

Trianionic pincer ligands offer two distinct advantages over traditional meridional-

tetradentate ligands. Catalysts supported by meridional-tetradentate ligands are

susceptible to deactivation pathways as product inhibition and μ-O dimerization. Here,

we are able to demonstrate that complex 2 featuring a trianionic OCO pincer ligand

doesn’t deactivate by either product inhibition (5) or formation of μ-oxo dimers (4)

(Figure 2-33). Rather, coordinating the oxidized substrate (OPPh3) to 2 or formation of

μ-oxo dimers renders the metal center more reactive towards O2.

Supporting this claim, the kinetic results for the oxidation of 2 reveal an

unprecedented autocatalytic mechanism, where product 3 accelerates O2 activation by

forming a μ-oxo dimer, complex 4. We now also conclude that M-O-M species can

68

directly react with oxidant.214, 215 Additionally, complex 4 is the first crystallographically

characterized dinuclear CrIV-O-CrIV complex and the EPR data (peak postiions, and the

g, D, and E parameters) provides a characteristic fingerprint to identify d2-d2, CrIV-O-CrIV

species that may enhance other researchers seeking to identify the presence of (CrIV)2(

μ-O) in their catalytic systems.

Simulating conditions for product inhibition, OPPh3 was added to the kinetic

oxidation trials and was found to increases the rate of O2 activation by 2. To further

understand the role of OPPh3 in facilitating O2 activation by 2, excess OPPh3 was

added to 2, which yielded 5. The single-crystal X-ray structure of 5 reveals a square

pyramidal geometry consisting of two OPPh3 ligands, one above and one below the

plane of the tBuOCO-3 pincer ligand.36 Complex 5 is more reactive towards O2 than

complex 2 due to the open coordination site trans to the Cr-Cpincer bond, which affords

O2 easier access to the metal center. This result clearly illustrates the advantage of

trianionic pincer ligand design. By occupying only three coordination sites, the fourth

coordination site trans to the central carbon donor becomes kinetically labile allowing

oxidant (O2) continued access and avoids product inhibition.

2.4 Experimental Section

2.4.1 General Considerations

Unless specified otherwise, all manipulations were preformed under an inert

atmosphere using standard Schlenk or glovebox techniques. Pentane, hexanes,

toluene, diethyl ether (Et2O), tetrahydrofuran (THF), and 1,2-dimethoxyethane (DME)

were dried using a GlassContour drying column. Benzene-d6 (Cambridge Isotopes) was

dried over sodium-benzophenone ketyl, distilled or vacuum transferred, and stored over

69

4 Å molecular sieves. CrCl2Me(THF)3 was prepared according to published

procedures.216 All other reagents were purchased from commercial vendors and

used without further purification.

2.4.2 Analytical Techniques

NMR Techniques: NMR spectra were obtained on, Varian Gemini 300 MHz,

Varian Mercury Broad Band 300 MHz, or Varian Mercury 300 MHz spectrometers.

Chemical shifts are reported in δ (ppm). For 1H and 13C{1H} NMR spectra, the solvent

peak was referenced as an internal reference.

IR Techniques: Infrared spectra were obtained on a Thermo scientific Nicolet

6700 FT-IR. Spectra of solids were measured as KBr discs.

EPR Techniques: (Vasanth Ramachandran, Mekhala Pati, and Naresh S. Dalal)

EPR measurements were conducted using a Bruker Elexsys-500 Spectrometer, at the

X-band, microwave frequency ~9.4 GHz in the temperature range of 4 to 300 K. The

microwave frequency was measured with a built-in digital counter and the magnetic field

was calibrated using 2,2-diphenyl-1-picrylhydrazyl (DPPH; g = 2.0037). The

temperature was controlled using an Oxford Instruments cryostat, to accuracy within

±0.1 K. Modulation amplitude and microwave power were optimized for high signal-to-

noise ratio and narrow peaks.

Elemental Analysis: Combustion analyses were performed at Complete

Analysis Laboratory Inc., Parsippany, New Jersey.

UV-Vis Techniques: UV-vis spectra were acquired on a Hewlett Packard 8453

spectrometer and variable temperature was maintained using Fisher Scientific Isotemp

10065.

70

Electrochemical Cyclic Voltammograms Techniques: (Marie C.Correia)

Electrochemical experiments were performed at ambient temperature in a glove box

using an EG&G PAR model 263A potentiostat/galvanostat and a three-compartment H-

cell separated by a medium porosity sintered glass frit. Electrolytic solutions consisted

of 0.1 M tetrabutylammonium hexafluorophosphate (TBAH) dissolved in either CH2Cl2

or THF. Cyclic voltammograms (CV) were recorded at 100 mVs-1 in 4 mL electrolytic

solution with 5 x10-3 M complex concentration. A glassy carbon electrode (3 mm

diameter) was used as the working electrode and a platinum flag as the counter

electrode. All potentials are reported versus SCE and referenced to Ag/Ag+. The

reference electrode consisted of a silver wire immersed in a freshly prepared acetonitrile

solution of 0.01 M AgNO3 and 0.1 M TBAH encased in a 75 mm glass tube with a fitted

Vycor tip. The Eo values for the Fc+/Fc couple in CH2Cl2 and THF were +0.47 V and

+0.58 V versus SCE respectively.217

2.4.3 Calculations

(Thomas G. Gray) Spin-unrestricted density-functional theory computations were

executed in Gaussisn03.218 Calculations employed Becke’s nonlocal exchange

functional219 along with the correlation functional of Perdew.220, 221 Full geometry

optimization was carried out using the standard 6-31G(d,p) basis set222-224 on all atoms;

a harmonic vibrational frequency calculation returned all-real frequencies and confirmed

the converged structure to be a local minimum of the potential-energy hypersurface.

Frequencies were calculated analytically. A single-point calculation on the optimized

structure was run using the TZVP basis set of Godbelt, Andzelm, and collaborators.225

Percentage compositions of molecular orbitals, overlap populations, and bond orders

between fragments were calculated using the AOMix program.226, 227 The g-tensor was

71

calculated using gauge-invariant atomic orbitals (GIAO).228, 229 All calculations are gas-

phase.

2.4.4 Synthesis of [tBuOCO]K2▪1.5THF (1)

(Joseph M. Falkowski) In a nitrogen filled glovebox, 597 mg (1.59 mmol) of

[tBuOCO]H3 was dissolved in 5 mL of THF. In a separate vial 128 mg (2.01 eq, 3.20

mmol) of potassium hydride was suspended in 2 mL of THF. The solution containing

[tBuOCO]H3 was added to the potassium hydride suspension and stirred vigorously at

room temperature for 4 h. The solution was then filtered and all volatiles removed in

vacuo to provide a colorless oil. The oil was triturated with pentane (3 x 1 ml) to yield 1

as a white powder (705 mg, 75%). 1H NMR (300 MHz, THF-d8, δ): 7.98 ppm (s, 1H, Ar-

H), 7.28 ppm (t, 3J = 7.79 Hz, 1H, Ar-H), 6.96 ppm (dd, 3J = 7.33 Hz, 4J = 1.83 Hz, 2H,

Ar-H), 6.89 ppm (dd,3J= 7.79 Hz, 4J = 2.29 Hz, 2H, H8,8'), 6.86 ppm (dd, 3J = 7.33 Hz,

4J = 2.29 Hz, 2H, H6,6'), 5.99 ppm (dd, J = 37.33, 3J = 7.33 Hz, 2H, H7,7'), 1.45 ppm

(s, 18H, H12,12'). 13C{1H} NMR (75 MHz, THF-d8, δ): 169.6 ppm (C10,10'), 144.7

ppm(C2,2'), 137.2 ppm (C9,9'), 134.5 ppm (C1), 132.19 ppm (C5,5'), 128.55 ppm (C4),

128.07 ppm (C6,6'), 126.43 ppm (C3,3'), 125.67 ppm (C8,8'), 108.17 ppm (C7,7'),

35.79ppm (C11,11'), 30.75 ppm (C12,12'). Anal. Calcd for C30H36CrK2O3; C: 68.92%;

H: 6.94%, Found; C: 68.53%; H 7.43%.

2.4.5 Synthesis of [tBuOCO]CrIII(THF)3 (2)

(Joseph M. Falkowski) In a nitrogen filled glove box (368mg, 1.04 mmol) of

CrCl2Me(THF)3 was dissolved in 20 mL of THF. In a separate vial 542 mg (1.04 mmol)

of 1 was dissolved in 20 mL of THF. The solution of 1 was then added dropwise to the

CrCl2Me(THF)3 solution with stirring at room temperature and stirred for 5 h. All volatiles

72

were removed in vacuo. Toluene was added and the solution was filtered. The filtrate

was evaporated to dryness to provide an oil that was dissolved in a minimal amount of

THF and cooled to -35 °C to yield 292 mg of 2 as a green crystalline solid (44% yield).

1H NMR (300 MHz, benzene-d6, δ): 8.23 ppm (br s), 4.90 ppm (br s), 1.45 ppm (br s), -

7.48 ppm (br s), -13.30 ppm (br s). μeff = 4.54 μB.11 Selected IR data of 3 (neat film): ν

(cm-1) 1390 (s), 1250 (s), 1260 (w), 1125 (w), 1063 (m), 1010 (m), 850 (s), 840 (w), 812

(w). Anal. Calcd for C38H48CrO5; C: 71.67%; H: 7.60%, Found; C: 71.24%; H 8.16%.

2.4.6 Synthesis of [tBuOCO]CrV≡O(THF) (3)

In a nitrogen filled glove box, 89 mg (0.140 mmol) of 2 was dissolved in 15 mL of

toluene. The reaction vessel was fitted with a y-adapter and attached to a Schlenck line.

The solution was degassed and then O2 gas was admitted (1 atm). The solution quickly

turned purple then over the course of 2 h turned red brown. The solution was degassed

and the volatiles removed in vacuo yielding 58 mg of 3 as brown powder. The solid can

be recrystallized by dissolving the brown powder in a minimal amount of toluene and

cooling the solution to -35°C (41% yield). Note: epr spectra of various samples of 3

routinely indicate the presence (2%) of a CrVCrV dinuclear complex. 1H NMR (300 MHz,

benzene-d6, δ) 11.4 ppm (br s), 9.0 ppm (br s), 7.29 (br s) 4.2 ppm (br s), 2.4 ppm (br

s), 1.2 (br s). μeff = 1.99 μB.11 Selected IR data of 3 (neat film): ν (cm-1) 1577 (w), 1549

(w), 1471 (w), 1410 (s), 1359 (w), 1320 (w), 1242 (m), 1193 (m), 1110 (w), 1054 (w),

988 (s), 875 (m), 858 (w), 838 (w). Anal. Calcd for C30H35CrO4; C: 70.43%; H: 6.90%,

Found; C: 70.61%; H 6.78%.

73

2.4.7 Synthesis of {[tBuOCO]CrIV(THF)}2(μ-O) (4)

Complex 2 (0.210 g, 3.28 x10-4 mol) was dissolved in 5 mL of toluene. One-half

of the solution (2.5 mL) was placed in a separate Schlenk flask and stirred under an

atmosphere of anhydrous O2 for 1 h to form 3 as a red solution. The solution of 3 was

evaporated to provide a red powder, which was brought into a glove box. The toluene

solutions of 2 and 3 were combined yielding a deep purple color and then the solvent

was evaporated to yield a purple powder. 1H NMR (300 MHz, C6D6): δ = 28.70 (ν1/2 =

570 Hz), 16.89 (ν1/2 = 675 Hz), 13.38, 1.79, and -30.57 (ν1/2 = 540 Hz) ppm. The powder

was dissolved in minimal Et2O and cooled to -35 °C yielding purple crystals of 4 and a

few green crystals of 2 (Joseph M. Falkowski).

2.4.8 Synthesis of [tBuOCO]CrIII(OPPh3)2 (5)

Solid triphenylphosphine oxide (0.158 g, 0.603 mmol) was added to a solution of 2

(0.193 g, 0.302 mmol) in toluene (20 mL) and stirred for 0.5 h. The solvent was

removed by vacuum and the solid was dissolved in a minimal amount of CH2Cl2 (5 mL)

then layered with hexane to yield 237 mg of dark green crystalline 5 (73% yield).

31P{1H} NMR (121.5 MHz, C6D6): not observed; 1H NMR ( 300 MHz,C6D6): δ = 7.62

(br), 6.67 (br), 4.28 (s, CH2Cl2), 1.46 (s), 1.24 (s), 0.88 (s), -3.35 (br), -6.91 (br), and -

13.20 (br) ppm. μeff = 4.62 μB.11 Selected IR bands: 1437, 1406, 1277, 1266, 1185,

1169, 1121,1111, 721, and 719 cm-1. Anal. Calcd. for C62H57O4CrP2 • CH2Cl2; C: 71.05;

H: 5.58. Found; C: 71.00; H, 5.63.

2.4.9 General Procedure for the Catalytic Oxidation of PPh3 with O2 by 2

Triphenylphosphine (0.962 g, 3.67 mmol) and 2 (8 mg, 0.012 mmol) was dissolved in

hexanes (40 mL). 1 atm of O2 (g) was admitted and the solution was stirred for 3 hrs.

74

Triphenylphosphineoxide precipitated from solution and was filtered. The identity of the

product and purity was verified by comparison of its 31P{1H} and 1H NMR spectra to an

authentic sample (yield = 66%, 0.676 g, 2.25 mmol).

2.4.10 General Procedure for the Catalytic Oxidation of PPh3 with air by 2

Triphenylphosphine (14 mg, 0.053 mmol) and 2 (5 mg, 0.007 mmol) was

dissolved in C6D6 (0.6 mL) and transferred to a NMR tube. The solution was exposed to

flowing air and shaken. The light green solution turned dark upon shaking and gradually

turned green, characteristic of [tBuOCO]CrIII(OPPh3)2 (5). The reaction progress was

monitored by 31P{1H} NMR until completion.

2.4.11 Stoichiometric 18O2 Catalytic PPh3 Oxidation Reaction

Triphenylphosphine (9.3 mg, 0.036 mmol) and 2 (3 mg, 0.005 mmol) was

dissolved in C6D6 (0.6 mL) and transferred to a J-Young NMR tube. The volume of the

headspace in the J-Young tube was determined to have a volume of 2.85 mL. The J-

Young tube was then attached to a Schlenk line, the solution was frozen, and the

headspace evacuated. Half equivalent of 18O2 (0.01777 mmol, 146 Torr, 2.25 mL) was

admitted to the headspace and the tube sealed. The solution was thawed and the

reaction was monitored by 31P{1H} NMR. When complete all volatiles were removed in

vacua and an ESI-MS of the resulting powder showed >96% of labelled 18O=Ph3.

2.4.12 General Sample Preparation for Kinetic Measurements

Oxygenated solvents were prepared by bubbling O2 through the solvent for 30

minutes and stored under an atmosphere of O2 for 6 hrs before use. The concentration

of O2 was taken to be the accepted literature value.193 The reference absorbance was

used as the initial concentration absorbance prior to reagent injection. A trend line was

75

fitted to the first 80% of the reaction progress and then used to extrapolate the observed

rate. Spectra were acquired in quartz cuvettes with septum caps.

2.4.13 Kinetic Simulations

Kinetic simulations were fitted using Kinetica version 1.0.17. The simulated rate

constants were obtained by fitting the experimental trials using a conjugate gradient

optimization with default convergence criterion of 0.01 and a dampening factor for

simplex of 0.9.

2.4.14 [2] vs time: Oxidation of 2 with O2 in THF

A 50 mL stock solution of 2 (21.2 mg, 3.31 x10-5 mol) in THF was prepared.

[2] variation:

In the sample cells, 0.25, 0.5, and 0.75 mL of stock solution of 2 was diluted with

2.25, 2.0, and 1.75 mL of THF, respectively. Oxygenated THF (0.5 mL) was added to

the sample cell via syringe, and the absorbance was monitored at 341 nm for 400 s.

[O2] variation:

Similarly, 0.5 mL of stock solution of 2 was diluted with 1.5, 1.0, and 0.5 mL of

THF and 1.0, 1.5, and 2.0 mL of oxygenated THF was added, respectively.

[THF] variation:

0.5 mL of stock solution of 2 was diluted with 1.5, 1.0, and 0.5 mL of THF and

0.5, 1.0, and 1.5 mL of hexanes, respectively, and then 0.5 mL of oxygenated THF was

added.

[OPPh3] variation:

A 20 mL stock solution of OPPh3 (73.3 mg, 2.63 x10-4 mol) in THF was prepared.

A 0.5 mL of stock solution of 2 was diluted with 0.5, 1.0, and 1.5 mL of THF and 1.5,

76

1.0, and 0.5 mL of OPPh3 solution, and then 0.5 mL of oxygenated THF was added to

the samples.

[3] variation:

A 10 mL of stock solution of 2 was exposed to an atmosphere of O2 for a 0.5 h.

The solution was dried under vacuum and redissolved in 10 mL of THF under an inert

atmosphere. Samples containing 0.5 mL of stock solution of 2 were prepared using 0.25

and 0.5 mL of a stock solution of 3 with 1.75 and 1.5 mL of THF, respectively and then

0.5 mL of oxygenated THF was inserted into the samples.

2.4.15 Variable Temperature: Oxidation of 2 with O2 in THF

A 25 mL stock solution of 2 (22.3 mg, 3.48 x10-5 mol) in THF was prepared. In

the sample cell, 0.4 mL of the stock solution of 2 was diluted with 2.1 mL oxygen-free

THF. Oxygenated THF (0.5 mL) was then added to the reaction cell via syringe and the

absorbance was monitored at 341 nm for 300 s. The temperatures for the sample cells

were set to 42 °C, 25 °C, 9 °C, and -2 °C and then 0.5 mL of ambient temperature

oxygenated THF was added resulting in a temperature change of 1-2 °C. As a result,

the temperatures were taken to be 40, 20, 10, and 0 °C. Between kinetic trials the

temperature was re-equilibrated to the initial thermal value. Special considerations

were taken for 0 °C trials in which a nitrogen-filled atmosphere was used to prevent ice

formation on the cuvette. Also for 10 °C trials, the cuvette was periodically wiped to

avoid water condensation.

77

Figure 2- 1. General mechanism for substrate oxidation including catalyst deactivation pathways of product inhibition and reversible formation of a M-O-M intermediate.

Figure 2- 2. Additional coordination site provided by a trianionic pincer ligand over

tetradentate ligands.

Figure 2- 3. Synthesis of 1.

78


Figure 2- 5. Molecular structure of 2 with ellipsoids at 50% probability. Hydrogen atoms and two THF molecules removed for clarity. The two mutually trans coordinated THF molecules are distorted over two positions and are removed for clarity. Selected bond lengths (Å): Cr1−C1 = 2.011(3), Cr1−O1 = 1.9227(17), Cr1−O2 = 1.9248(17), Cr1−O3 = 2.1938(18), Cr1−O4 = 2.0624(18), and Cr1−O5 = 2.0566(18).

79

Figure 2- 6. Activation of O2 by 2 to yield complex 3.

Figure 2- 7. Molecular structure of 3 with ellipsoids at 50% probability. Hydrogen atoms

removed for clarity. Selected bond lengths (Å) and angles (°): Cr1−C1 = 2.009(2), Cr1−O1 = 1.8098(17), Cr1−O2 = 1.8166(17), Cr1−O3 = 2.1781(17), Cr1−O4 = 1.5683(18), O1−Cr1−O2 = 126.89(8), O1−Cr1−O4 = 116.73(9), O2−Cr1−O4 = 115.82(9), C1−Cr1−O4 = 98.84(9), and C1−Cr1−O3 = 165.27(8).

80

Figure 2- 8. Plot of the α-SOMO (A) and α-LUMO (B) of model complex 3′, contour

level 0.03 a.u..

Figure 2- 9. Aerobic oxidation of PPh3 catalyzed by complex 2.

A B

81

Figure 2- 10. UV-vis spectral change of 2 in THF upon addition of O2 (25 °C).

Figure 2- 11. Concentration vs time (s) for the oxidation of 2 by O2 in THF; within 1st

80% (blue), after 80% (red) (25 °C).

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

300 350 400 450 500

Ab

sorb

an

ce

wavelength (nm)

0

2

4

6

8

10

12

0 50 100 150 200

[2]

x10

5 (

M)

time (s)

[2] = 1.10E-4 M

82

Figure 2- 12. Concentration (2) vs time (s) for the oxidation of 2 (0.55 – 1.65 (x10-4) M) with O2 (1.66 x10-3 M) in THF (25 °C).

Figure 2- 13. Plot of -Δ[2]/Δt vs [2] ([2] = 0.55 – 1.65 x10-4 M; [O2] = 1.66 x10-3 M (THF, 25 °C).

0

2

4

6

8

10

12

14

16

18

0 50 100 150 200

[2]

x10

5 (

M)

time (s)

[2] = 1.10E-4 M

[2] = 0.55E-5 M

[2] = 1.65E-4 M

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

0 0.5 1 1.5 2

Δ[2

]/Δ

t x10

6

(M/s

)

[1] x104 M

83

Figure 2- 14. Concentration (2) vs time (s) for the oxidation of 2 (1.10 x10-4 M) with O2

(1.66 - 6.66 (x10-3) M) in THF (25 °C).

Figure 2- 15. Plot of rate -Δ[2]/Δt vs [O2] ([2] = 1.10 x10-4 M; [O2] = 1.66 - 6.66 (x10-4) M) in THF (25 °C).

0

2

4

6

8

10

12

0 50 100 150 200

[2]

x10

5 (M

)

time (s)

[O2] = 1.66E-3 M

[O2] = 3.22E-3 M

[O2] = 4.99E-3 M

[O2] = 6.66E-3 M

0

0.5

1

1.5

2

2.5

3

3.5

4

0 2 4 6 8

Δ[2

]/Δ

t x10

6

(M/s

)

[O2] x103 (M)

84

Figure 2- 16. Plot of rate –Δ[1]/Δt vs XTHF ([2] = 1.10 x10-4 M; [O2] =1.66 x10-3 M; THF/hexane (mL:mL) = 2.5:0.5, 2.0:1.0, 1.5:1.5) at 25 °C.

Figure 2- 17. Concentration of 2 (1.84 x10-4 M) vs time in THF upon addition of O2 (1.66 x10-3 M) at 40 °C (red), 20 °C (yellow), 10 °C (light blue), and 0 °C (dark blue).

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

0.5 0.6 0.7 0.8 0.9 1

Δ[2

]/Δ

t x10

6

(M/s

)

XTHF

0

2

4

6

8

10

12

14

16

18

20

0 100 200 300 400 500 600 700

[2]

x10

5 (M

)

time (s)

25 °C

10 °C

0 °C

85

Figure 2- 18. Concentration of 2 vs time (s) for the oxidation of 2 (1.10 x10-4 M) by O2 (1.66 x10-3 M) with increasing [3] (0, 5.5 x10-5, and 1.10 x10-5 M) in THF (25 °C).

Figure 2- 19. Plot of Δ[2]/Δt for the oxidation of 2 (1.10 x10-4 M) by O2 (1.66 x10-3 M) with increasing [3] (0, 0.55 x10-4, and 1.10 x10-4 M) in THF (25 °C).

0

2

4

6

8

10

12

0 50 100 150 200

[2]

x10

5 (

M)

time (s)

[3] = 0 M

[3] = 0.55E-4 M

[3] = 1.1E-4 M

0

0.5

1

1.5

2

2.5

3

0 5 10 15

Δ[2

]/Δ

t x10

6 (

M/s

)

[3] x105 (M)

86

Figure 2- 20. Equilibrium between 2 and 3 and the dimer adduct 5.

Figure 2- 21. Molecular structure of {[tBuOCO]CrIV(THF)}2O (5) with ellipsoids drawn at the 50% probability level and hydrogen atoms and an ether lattice molecule removed for clarity.

87

Figure 2- 22. The π-bonding MO and ligand field splitting diagram of the CrIV ion in 5.

Figure 2- 23. Variable temperature high frequency (240 GHz) powder EPR spectra of major 5 and minor 2. The boxed part of the spectrum at 300 K is due to the noise from the spectrometer electronics.

88

Figure 2- 24. Simulated (a) and experimental (b) powder EPR spectra of 5 and 2 at 240 GHz and 4.5 K. The simulated spectrum (b) is the sum of the individually simulated spectra of 5 and 2. Peak assignments: Complex 1 (S = 1.5): allowed transitions = 3, 5, 6, 7 and 9, forbidden transition = 1; Complex 5 (S = 2): allowed transitions = 4, 5, 6, 7 and 8, forbidden transition = 2. The resonances 5, 6 and 7 are overlapping signals from both 2 and 5.

89

Figure 2- 25. Molecular structure of {[tBuOCO]CrIV(THF)}2O (5) with ellipsoids drawn at

the 50% probability level and hydrogen atoms and an ether lattice molecule removed for clarity.

90

Figure 2- 26. Proposed mechanism for O2 activation by 2.

91

Figure 2- 27. Simulated [2] (0.55 - 1.65 x10-4 M) vs time (s) at [O2] = 1.66 x10-3 M. Correlation (R2) values of simulated and experimental trials at 0.55 x10-4 M 2 (0.999), 1.10 x10-4 M 2 (0.999), and 1.65 x10-4 M 2 (0.999) (THF, 25 °C).

Figure 2- 28. Simulated [2] (1.10 x10-4 M) vs time (s) at different concentrations of [O2] (1.66 – 6.66 x10-3 M). Correlation (R2) values of simulated and averaged experimental trials at 1.66 x10-3 M O2 (0.999), 3.33 x10-3 M O2 (0.998), 4.99 x10-3 M O2 (0.999) and 6.66 x10-3 M O2 (0.995) (THF, 25 °C).

0

2

4

6

8

10

12

14

16

18

0 50 100 150 200

[2]

x10

5 (

M)

time (s)

exp. [2] = 1.65E-4 M

exp. [2] = 1.10E-4 M

exp. [2] = 0.55E-4 M

sim. [2] = 1.65E-4 M

sim. [2] = 1.10E-4 M

sim. [2] = 0.55E-4 M

0

2

4

6

8

10

12

0 50 100 150 200

[2]

x10

5 (M

)

time (s)

exp. [O2] = 1.66E-3 Mexp. [O2] = 3.22E-3 Mexp. [O2] = 4.99E-3 Mexp. [O2] = 6.66E-3 Msim. [O2] = 1.66E-3 Msim. [O2] = 3.22E-3 Msim. [O2] = 4.99E-3 Msim. [O2] = 6.66E-3 M

92

Table 2- 1. Average calculated rate constants for the oxidation of 2 (1.84 x10-4 M) with O2 (1.66 x10-3 M) in THF at 25 °C, 20 °C, and 0 °C.

T (°C) 25 10 0

k1 (s-1) 2.6(±0.6) 1.2(±0.1) 0.5(±0.3)

k4 (M-1s-1) 396.8(±0.7) 179(±8) 50(±9)

k-4/k5 6.1(±2.3) x10-3 2.9(±0.4) x10-3 1.8(±0.6) x10-3

Figure 2- 29. Simulated [2] vs time for the oxidation of 2 (1.65 x10-4 M and 1.84 x10-4 M) with O2 (1.66 x10-3 M) using the average calculated rate constants from Table 1.

0

2

4

6

8

10

12

14

16

18

20

0 100 200 300 400 500 600 700

[2]

x10

5

time (s)

25 °C

10 °C

0 °C

25 °C simulation

10 °C Simulation

0 °C Simulation

93

Figure 2- 30. A plot of [2] vs time with increasing [OPPh3] (0 – 0.1 M). [O2] = 1.66 x10-3

M and [2] = 1.10 x10-4 M (THF, 25 °C).


0

2

4

6

8

10

12

0 50 100 150 200

[2]

x10

5 (

M)

time (s)

[OPPh3] = 0 M

[OPPh3] = 2.33E-3 M

[OPPh3] = 4.66E-3 M

[OPPh3] = 6.99E-3 M

[OPPh3] = 1.04E-1 M

94

Figure 2- 32. Molecular structure of 4 with ellipsoids at 50% probability. Hydrogen

atoms and CH2Cl2 removed for clarity. Selected bond lengths (Å) and angles (°): Cr1−C1 = 1.9761(17), Cr1−O1 = 1.9211(11), Cr1−O2 = 1.9312(12), Cr1−O3 = 1.9771(12), Cr1−O4 = 1.9896(11), O1−Cr1−O2 = 175.28(5), O3−Cr1−O4 = 157.38(5), C1−Cr1−O3 = 98.96(6), and C1−Cr1−O4 = 103.62(6).

95

Figure 2- 33. New general mechanism for substrate oxidation featuring .

96

CHAPTER 3 THE INFLUENCE OF REVERSIBLE TRIANIONIC PINCER OCO3- μ-OXO CrIV DIMER FORMATION ([CrIV]2(μ-O)) AND DONOR LIGANDS IN OXYGEN-ATOM-TRANSFER

(OAT)

3.1 Introduction

Trianionic pincer ligands present multiple approaches to creating reactive

complexes for catalysis and/or small molecule activation. In addition, a trianionic pincer

ligand can be used as a model platform to investigate atom transfer processes that may

be relevant to other catalytic systems. For example, Veige and coworkers investigated

the N-atom transfer from an anionic molybdenum nitride to synthesize nitriles from acid

chlorides.38 These model systems are of considerable importance in the quest for

catalysts that incorporate dinitrogen into organic substrate.230-238

In Chapter 2, we presented the distinct advantages of using a trianionic OCO

pincer ligand for oxidation catalysts. Here, we will demonstrate potential problems that

can occur during oxidation catalysis due to the formation of μ-oxo dimers in solution

(Figure 3-1). In particular, investigating the role of μ-oxo dimer formation during oxygen-

atom transfer (OAT) to PPh3 provides an informative comparison to tetradentate

ligands.

During a catalytic cycle, OAT from a metal center to substrate is deceptively

simple for a straightforward reaction involving the transfer of a single atom. The

mechanism of this process is dependent on the metal center, the oxidation state, and

the corresponding d-electron count of the complex.139 Even for a simple OAT from a

high valent d0 metal-oxo complex, theoretical and experimental studies indicate the rate

M. E. O'Reilly, T. J. Del Castillo, K. A. Abboud and A. S. Veige, Dalton Trans., 2012, 41, 2237-2246. -Reproduced by permission of The Royal Chemical Society.

97

of OAT is dependent on a combination of steric and electronic properties of the

substrate and metal coordination sphere which dictates the symmetry, and therefore the

density of states,118, 119, 239 that can mix at the transition state.118-121, 136, 240

Another dimension of complexity is the role of donor ligands during the OAT

event. Donor ligands are well-known to accelerate substrate oxidation by chromium and

manganese catalysts.241 One hypothesis for the rate enhancement is that the donor

ligand coordinates trans to the M≡O bond, and thereby weakens the M≡O bond.128, 189,

242-247 Another possible explanation is a change in the ancillary ligand orientation,

allowing for a more accessible pathway for the subtrate to approach the M≡O π*-orbital.

Evidence for the latter appears in the enantioselective epoxidation of olefins,241, 248-250

where coordinating a donor ligand to a chiral salen complex alters the ligand framework

influencing asymmetric induction around the M≡O.246, 251-256 Similarly, adding a chiral

donor ligand to an achiral metal-salen catalyst can also induce asymmetric OAT to

olefins.253-256

Weakening of the M≡O and ancillary ligand rearrangement by donor ligands

provide reasonable explanations for the observed rate enhancement, yet donor ligands

may have another more subtle effect. Recent studies of OAT from chromium141, 155-158,

160, 244, 257 and manganese161-165, 168-175, 258-260 oxidation catalysts postulate that the

formation of an μ-oxo complexes from the comproportionation of Mn+ and M(n+2)+=O

species are prevalent during catalysis. Despite their prevalence, μ-oxo complexes are

elusive and ill-characterized. One notable exception is an isolable [CpCrIVMe2]2(μ-O),

but the complex was characterized only by 1H NMR spectrscopy.187 The μ-oxo

intermediates261 are thermodynamic sinks that suppress the rate of oxidation (Figure 3-

98

1).140, 141, 260-262 Strong σ-donor ligands promote the dissociation of [(L)MnIV]2(μ-O) and

[(L)CrIV]2(μ-O) (L = salen or porphyrin) intermediates.140, 158, 169, 215 Thus, an overlooked

explanation is that donor ligands enhance substrate oxidation by preventing μ-oxo dimer

formation.

Though the formation of μ-oxo intermediates during oxidative catalysis has been

detected using 1H NMR,164, 165 EPR,158 UV-visisble spectrophotometry (UV-vis),175 and

mass spectrometry;157, 163, 168, 246, 257-259 a convenient means to identify their presence is

by evaluting the kinetic profile of the OAT reaction. Bruice et al. provide the only

example of the kinetic consequence of μ-oxo intermediates during OAT from a (L)CrVO

complex (L = porphyrin).156 The depletion of monomeric (L)CrVO follows a non-standard

kinetic decay profile, and a strong absorption corresponding to a μ-oxo intermediate

increases initially then slowly declines over the reaction period.

The synthesis of complexes 3 and 4 from Chapter 2 exemplify the rare

occurance of an isolable CrV≡O and (CrIV)2(μ-O) species that presents the opportunity to

directly report on the influence of a μ-oxo dimer during OAT. We now present the first

mechanistic investigation of OAT from an discrete μ-oxo dimer. In addition, we are able

to examine the role of donor ligands on the rate of OAT in relation to μ-oxo dimer

participation.


3.2.1 Identity of the Active OAT Agent in THF

The infrared spectrum of complex 3 exhibits a strong CrV≡O stretch at 988 cm-1.

Solution EPR measurements confirm a d1 CrV oxidation state for 3. However, routinely

prepared powder samples of 3, prior to recrystallization, exhibit an EPR spectrum with

two separate d1 signals at giso = 1.9747 and giso = 1.9762. Recrystallized 3 produces a

99

single resonance at 1.9747 in toluene (Figure 3-2, spectrum A). Dissolving the same

material used to generate spectrum A in 50% v/v THF/CH2Cl2 yields the second signal

at 1.9762 (Figure 3-2, spectrum B).

The interconversion of two distinct EPR signals of complex 3 by changing the

solvent from toluene to THF/CH2Cl2 suggests the two different species are

[tBuOCO]CrV(O)(THF) (3) and [tBuOCO]CrV(O)(THF)2 (3a) (Figure 3-3). In the latter, a

second THF binds to yield the coordinately saturated species 3a. Figure 3-4 depicts the

changes in the EPR spectrum of [tBuOCO]CrV(O)(THF) (3) (red) in toluene upon

addition of one-half (green) and a full equivalent of THF (blue), indicating an equilibrium

between 3 and 3a (Figure 3-3).

3.2.2 Mechanism of OAT from Mononuclear 3 and 3a

Both 3 and 3a transfer an oxygen atom to trialkylphosphines to yield

[tBuOCO]CrIII(THF)3 (2) and trialkylphosphine oxides. Figure 3-5 illustrates the OAT

from 3a in THF solution to yield 2. UV-vis spectrophotometry provides a suitable method

for studying the OAT. A color change from red-brown to green occurs when 3a reacts

with PPh3 to form 2 and OPPh3.36 Figure 3-6 depicts the time-dependent changes in

absorption spectra from a 0.11 mM solution of 3a upon addition of a ten-fold excess of

PPh3.

Measuring the changes in the absorption at 405 nm provides suitable data to plot

the relationship between the concentration of 3a vs time. Figure 3-6 depicts a first-order

curve for the depletion of 3a under pseudo-first order conditions. A ln[3a] vs time plot

confirms the first-order dependency in 3a (Figure 3-7) and the slope provides an

experimental value for kobs.

100

3.2.3 [PPh3] Dependence

A series of experiments varying the concentration of PPh3 from 1.07 to 2.14 mM

reveals a first order dependence in [PPh3]. Figure 3-8 depicts a plot of kobs vs [PPh3]

from the pseudo-first order rate law, d[3a]/dt = kobs[3a] where kobs = k1[PPh3]. Dividing

the measured kobs by [PPh3] yields the rate constant k1.

3.2.4 Variable Temperature Studies and Eyring Plot

Conducting the OAT between 0 and 40 ºC (±1 ºC) provides the temperature

dependent rate constants and an Eyring plot analysis provides ΔS‡ and ΔH‡. See

Appendix for the accompanying raw data. Figure 3-9 depicts a ln(k1/T) vs 1/T plot. The

ΔS‡ for OAT is -18(±3) cal/molK and is consistent with a nucleophilic attack by

phosphine during the rate-determining step. The relatively low enthalpy of activation

(ΔH‡ is 9.4(±0.8) kcal/mol) corresponds to a fast reaction that is complete within two

minutes (15 °C).

3.2.5 PR3 Size Rate Dependence

Performing spin-unrestricted density-functional theory calculations on 3', an

analogue of 3 having methyl groups in place of tert-butyl, elucidates the possible CrV≡O

orbital involved in nucleophilic attack by PPh3. The -LUMO is primarily a CrV≡O *

combination, with 62% Cr, 26% oxo, 2.6% trianionic pincer ligand, and 9.4% THF

character. The CrV≡O π*-orbital is a reasonable point of attack by external nucleophiles

such as PPh3.

Nucleophilic attack of the CrV≡O π*-orbital should be more favorable for less

sterically bulky phosphines. In keeping with this hypothesis, the relative rates of OAT for

trimethylphosphine (PMe3), triphenylphosphine (PPh3), and tri-tert-butylphosphine

(PtBu3) are slower for larger phosphines. Table 3-1 contains the rates of OAT for the

101

three different phosphines at 15 °C and equimolar concentrations. The relative rates of

kobs for PMe3:PPh3:PtBu3 are 2976:235:1, respectively. These results are consistent with

a bimolecular side-on attack of the CrV≡O LUMO.118, 119, 263

Figure 3-10 depicts a straightforward mechanism that fits the kinetic data. The

incoming PPh3 attacks the electrophilic oxygen atom of 3a cleaving the CrV≡O bond.

The first-order dependence on both 3a and PPh3 and the negative ΔS‡ (-18(±3) cal/mol)

support k1 as the rate-determining step. In subsequent fast steps, THF displaces the

coordinated OPPh3.

3.2.6 Role of Donor Ligands on OAT

Literature precedent suggests that strongly coordinating solvents and ligands,

such as phosphine oxides, methanol, and acetonitrile, accelerate the rate of OAT.128, 189,

242-247 Monitoring the rates of OAT at different concentrations of OPPh3 (0 - 1.31 mM) in

THF allows the determination of OPPh3 influence in OAT. Figure 3-11 depicts a plot of

kobs vs [OPPh3] (-d[3a] = kobs[3a]) and indicates OPPh3 does not affect the overall OAT

rate. Using this data, k1 at 22 °C is 69.5(±1.9) M-1s-1.

Similarly, solvent coordination may influence the rate of OAT. Table 3-2 contains

the observed rates for OAT in acetonitrile (MeCN), CH2Cl2, and THF. Surprisingly, more

strongly coordinating solvents, such as acetonitrile, do not change the rate. EPR

confirms indeed the MeCN coordinates to 3, but rather weakly since applying vacuum

readily removes MeCN and the IR spectrum does not contain any C≡N stretching. The

OAT reactions in CH2Cl2 did not yield isosbestic points without the addition of THF. The

THF is necessary to satisfy the coordination sphere of the resulting reduced CrIII ion.

Adding 50 µL of THF to the CH2Cl2 trials results in clean isosbestic points but the rate is

identical to OAT in THF.

102

3.2.7 Synthesis and Characterization of [tBuOCO]CrV(O)(CH2PPh3) (6)

One of the strongest neutral two-electron σ-donor ligands is the phosphorus ylide

R3P+CH2ˉ,

264 even stronger than N-heterocyclic carbene (NHC) ligands.265 To

investigate the potential role this donor ligand has on OAT, complex 3 was treated with

one equivalent of Ph3PCH2 in toluene to yield [tBuOCO]CrV(O)(CH2PPh3) (6) according

to Figure 3-12. The infrared spectrum of 6 reveals a strong absorption at 976 cm-1

corresponding to a weaker CrV≡O bond, compared to 3, which appears at 988 cm-1 in 3.

The increased electron density donated to the CrV ion by the phosphorus ylide

ˉCH2P+Ph3 versus THF better stabilizes the +5 oxidation state of chromium.

Consequently the π-donation from the oxo relaxes and weaker O-M π-bond forms.

Consistent with a more electron-rich CrV ion, the cyclic voltammagram of 6 in CH2Cl2

(Figure 3-13) reveals a first reduction potential at -1.968 V, whereas the first reduction

potential for the CrV ion in 3 appears at 0.062 V. Essentially, complex 6 is more difficult

to reduce than 3, and a consequence of the large negative reduction potential is that

complex 6 is not thermodynamically competent to oxidize PPh3 or PMe3.

Figure 3-14 depicts the solution EPR spectrum of 6 in hexanes. The weak

satellite signals correspond to the 53Cr isotope (S = 3/2) and yields a hyperfine splitting

of 18.58 mT. The intense resonance at g-value = 1.982 corresponds to the remaining Cr

isotopes and is a triplet due to coupling to the protons of CH2PPh3 with a hyperfine

splitting of 0.199 mT. A second hyperfine splitting (A(31P) = 0.066 mT) appears as weak

shoulders lying to the right of the main signals. EPR simulations using Easyspin.3.1.6266

indicate the second hyperfine splitting corresponds to a doublet arising from coupling to

31P (S = ½).

103

Brown single crystals deposit at -35 °C from a concentrated solution of 6 in

toluene. Figure 3-15 depicts the molecular structure of 6 obtained by single-crystal X-

ray analysis. Complex 6 is pseudo Cs-symmetric and consists of a CrV ion in a distorted

square pyramidal coordination geometry with an Addison parameter of 0.053.194 The Cr-

oxo bond length is 1.5699(11), which is statistically identical to the corresponding bond

found in 3 (1.5683(18) Å),57 and is typical for CrV-oxo complexes.67-75 The geometry of 6

distorts significantly from that of the precursor 3. The C12-Cr-O4 angle of 145.05(7)°

is significantly smaller than in 3 (165.27(8)°), reflecting the change from THF ligation to

CH2PPh3. Also, the central aryl ring of the pincer ligand is severely bent out of plane

from the peripheral rings to create a butterfly orientation (Figure 3-15). Planes

comprised of the peripheral arene carbon atoms bisect the plane comprised of the

central ring carbons by 32.8° for 6 and 28.1° for 3.

3.2.8 Role of Dinuclear μ-oxo Dimer {[tBuOCO]CrIV(THF)}2(μ-O) (4) in OAT

Few of the previous studies that propose competent μ-oxo Cr and Mn dimer

species in oxidation catalysis were able to assess whether the dimers participate in

OAT to substrate.156, 158, 161 Offering a chance to examine this directly, complex 4 was

tested as an OAT transfer agent.

UV-vis spectrophotometry is a suitable method for monitoring the OAT from the

μ-oxo dimer 4 to PPh3 in noncoordinating solvents. Figure 3-16 depicts the changes in

absorption spectra of 4 in CH2Cl2 upon addition of PPh3. Observing the decay of 4 is

optimal at a wavelength of 850 nm; the interference from CrVO (red) and CrIII (green)

absorption is minimal.

104

Measuring the changes in absorption at 850 nm produces a plot of [4] vs time.

Figure 3-17 depicts the average concentration vs time profile of three experimental

trials. The decay of [4] vs time does not follow first-order kinetics as exemplified in the

non-linear ln[4] vs time plot (Figure 3-17).

Figure 3-18 depicts the time dependent decay of complex 4 in the presence of

PPh3 (1.10, 2.21, and 4.42 (x 10-3) M). The data clearly indicate a zero-order

dependence on the concentration of PPh3, suggesting complex 4 must first break apart

into mononuclear CrIII and CrV(O) prior to OAT.

Figure 3-19 depicts the proposed mechanism of OAT from 4 to PPh3 in CH2Cl2.

The rate-determining step is the fragmentation of 4 to provide a proposed low-

coordinate CrIII species 7 and 3. The dissociation of 4 is relatively slow, and the

equilibrium favors the dimer. Upon cleavage of 4, the newly formed 3 reacts with PPh3

to yield OPPh3 and a second equivalent of 7. The exact composition of the low-

coordinate complex 7 is unknown. As the concentration of OPPh3 builds, a more

accurate description of the CrIII containing products would include different coordination

complexes with bound OPPh3 and THF.57

Varying the concentration of 4 reveals that OAT occurs faster at more dilute

concentrations. This is counterintuitive. Why would a higher concentration of 4 inhibit

OAT if complex 4 is the source of the OAT agent 3? Figure 3-20 depicts the average

(three independent measurements) decay of 4 at three different concentrations. The [4]

vs time plots were simulated using Kinetica 2003 using the decay plots of 4 as the input

data, and the reaction scheme in Figure 3-19 as the model mechanism. The kinetic

trials established above (Figure 3-11) for the direct OAT from 3a to PPh3 in THF provide

105

an experimentally determined value for k2 (formerly k1 in Figure 3-5) as 69.5(±1.9) M-1s-1

(22 °C). An approximate rate constant for k1 is determined by analyzing the rate law for

the mechanism. Equation 3- 1 depicts the mathematical expression of the rate law for

the mechanism in Figure 3-19.

[ ]

[ ][ ]

[ ] [ ] (3- 1)

[ ]

[ ] (3- 2)

At early reaction times ( t < 150 s), the concentration of 7 is negligle such that

k2[PPh3] >> k-1[7], thus simplifying Equation 3- 1 to Equation 3- 2 and plotting ln[4]

versus time during this period provides a linear correlation and k1 as the slope

(Appendix). For the conditions [4] = 3.11 x10-4 M, [PPh3] = 1.1 x10-3 M, 22 °C, in CH2Cl2;

k1 = 8.38(±0.69) x10-4 s-1 (averaged from three independent measurements).

The rate law also (Equation 3- 1) provides an opportunity to experimentally

determine a value for k-1. Equation 3- 3 depicts the full integrated rate law from Equation

3- 1. The [Cr]tot is the total concentration of chromium as defined in Equation 3- 4.

( [ ] [ ]) [ ] [ ] [ ] (3- 3)

where, [ ] [ ] [ ] [ ] (3- 4)

Employing the assumption that k-1[Cr]tot >> k2[PPh3] simplifies Equation 3- 3 to

Equation 3- 5. Coincidentally, the same rate law is obtained from Equation 3- 1 directly,

assuming k-1[7] >> k2[PPh3], an assumption which is only valid at the end of the reaction

time (t > 5000 s) when [7] accumulates.

[ ] [ ] [ ] [ ]

(3- 5)

106

Employing the identical conditions for the determination of k1 ([4] = 3.11 x10-4 M,

[PPh3] = 1.1 x10-3 M, 22 °C, in CH2Cl2), Figure 3-21 depicts the linear correlation plot of

2[4] – [Cr]totln[4] vs time. The slope is the product of the rate constants k1, k2[PPh3], and

1/k-1. Since the values of [PPh3], k1 (8.38(±0.69) x10-4 s-1) and k2 (69.5(±1.9) M-1s-1 are

known, the approximate value of k-1 = 1.95(±0.23) x103 M-1s-1. Using the k1 and k-1 rate

constants, Keq = k-1/k1

for the formation of 4 from CrIII and CrV(O) in CH2Cl2 is

2.33(±0.36) x106.

Kinetic simulations of the concentration versus time profiles were conducted to

examine the validity of the mechanism proposed in Figure 3-19. Simulating the

concentration versus time profiles for the reaction of 4 with PPh3, and the elementary

reaction steps in Figure 3-19, provides an estimate of the rate constants k1 and k2/k-1.

Since the value of k2 (previously labeled k1 above) is experimentally determined from

OAT from 3a to PPh3 in THF, the k2 rate constant was fixed at 69.5 M-1s-1. Table 3-3

provides the average simulated rate constants, which are close in magnitude to the

experimental values. The corresponding calculated equilibrium constant for the

formation of 4 is Keq(calc) = 1.66(±0.31) x 106.

For visual verification, the calculated rate constants from Table 3-3 can be

employed to regenerate the decay of [4] versus time profiles. Figure 3-22 depicts the

concentration versus time profiles for [4] = 3.11, 1.56, and 0.78 (x10-4) M and from

visual inspection the calculated rate constants provide a good fit to the experimental

data. Statistically, the correlation values between experimental decay and simulated

decay profiles are 0.999, 0.999, and 0.990 for [4] = 3.11, 1.56, and 0.78 (x10-4) M,

respectively. Small deviations between simulated and experimental data occur toward

107

the end of the reaction; more specifically the simulated decay lags behind the

experimental decay. This deviation arises from the formation of OPPh3 as the reaction

progresses, which is known to bind strongly to CrIII, and thus shifts the equilibrium in

favor of mononuclear CrIII and CrVO complexes over the dimer 4. 57, Finally, adding two

equivalents of OPPh3 to a C6D6 solution of 4 results in disappearance of the dimer

signals at 18.58, 16.32, and -27.22 ppm in the 1H NMR, confirming OPPh3 role in the

equilibrium.

Finally, in THF, as soon as the CrV(O) completes an OAT event, the Cr(III)

complex that forms coordinates a THF molecule which prevents dimerization, thus the

reactions are generally swift (150 s to complete). However, in non-donor solvents the

Cr(III) that forms rapidly combines with CrV(O) to form the μ-dimer 4, exemplified by the

large equilibrium constant Keq = 2.33(±0.36) x106. Indeed, this is observed; upon

additional of PPh3 to 3 in CH2Cl2, the immediate (<10 s) formation of the μ-oxo dimer 4

is observed as a broad absorption from 700 nm to 850 nm (Figure 3-23). Plotting the

change in absorption at 800 nm versus time indicates the reaction requires more than

3000 s to complete.

3.3 Conclusions

Trianionic pincer ligand are a versatile ligand platform to investigate oxygen-atom

transfer reactions. In Chapter 2, we presented an aerobic oxidation catalyst featuring a

trianionic OCO pincer ligand that avoids catalyst deactivation preventing reoxidation by

product inhibition and μ-oxo dimerization. The synthesis of complexes 3 and 4 examplify

a rare occurance of an isolable isolation CrV≡O and (CrIV)2(μ-O) species, which lends

itself to OAT investigation. In particular, interest in the OAT from M-O-M stems from the

hindrance that M-O-M dimer formation presents during catalyzed oxidation reactions

108

(Figure 3-1). Previous kinetic analysis of OAT reactions measuring the indirect

formation of Cr-O-Cr species postulate that the dimers do not transfer an oxygen atom

directly to substrate. Rather, the dimer breaks apart prior to OAT. By observing the

OAT directly from complex 4, our study provides additional evidence that O-atom

transfer indeed occurs after dimer cleavage (Figure 3-19).

The OAT from 3a to PPh3 in THF occurs quite swiftly (~ 100 s to completion),

yeilding an overall second order rate law. The rate of OAT is dependent on the size of

the substrate. In THF, the relative rates (kobs) of OAT from 3a to PMe3, PPh3, and PtBu3

are 2976:235:1 s-1, corresponding to greater difficulty experienced by sterically bulky

substrate in achieving the proper orientation needed for OAT.

The OAT from complex 4 to PPh3 is remarkably slow taking over 5 h to complete.

The zero-order dependence in PPh3 indicates that the dimer dissociates prior to OAT.

However, the OAT reaction from 4 does not follow first order kinetics. The OAT from 4

reveals a unique kinetic feature where higher concentration of 4 yields a slower rate of

OAT, which is contrary to expected results since 4 is the source of CrV(O). Kinetic

analysis shows that the kinetic profile anomalies arise from a product-inhibition

mechanism, where the formation of the CrIII species, 7, impedes the dissociation of the

4.

EPR data indicates that, in THF, complex 3 coordinates a second THF ligand to

provide 3a. The availability of a sixth coordination site allows us to investigate donor

ligand effects on the rate of OAT. Surprisingly, the OAT from 3 to PPh3 conducted in

THF, MeCN, and CH2Cl2/THF reveals no rate acceleration or retardation in any of the

solvents. Adding OPPh3, a donor ligand, likewise does not affect the rate of OAT.

109

However, the OAT from 3 in non-coordinating CH2Cl2 takes over 4 h to complete and

UV-vis spectroscopy reveals the immediate formation of the μ-O dimer 5.

Using the trianionic pincer ligand as a platform to investigate OAT, we present a

case for the role of donor ligands. This study allows us to conclude that the role of donor

ligands is not necessarily to weaken the M≡O bond during OAT. In fact, adding a very

strongly donating ligand can prevent OAT by making the transfer thermodynamically

unfavorable, as in the case of [tBuOCO]CrVO(CH2PPh3) (6). Instead, the donor ligands

serve an important role during OAT by preventing rate-inhibiting μ-oxo dimer formation.

It is possible that prior OAT studies exhibiting rate enhancement from donor ligands

have been misinterpreted, and instead the rate increases are actually the consequence

of breaking up putative μ-oxo dimers. Finally, this work illustrates the care that must be

taken when selecting an appropriate donor ligand that inhibits μ-oxo dimer formation

while still thermodynamically-permitting OAT.

3.4 Experimental Section


Unless specified otherwise, all manipulations were performed under an inert


toluene, acetonitrile, dichloromethane, and tetrahydrofuran were dried using a

GlassContour drying column. Benzene-d6 (Cambridge Isotopes) was dried over sodium-

benzophenone ketyl, distilled or vacuum transferred, and stored over 4 Å molecular

sieves. All other reagents were purchased from commercial vendors and used without

further purification.

110


Kinetic Simulations: Kinetic simulations were performed using Kinetica 2003

software.

NMR Techniques: NMR spectra were obtained on Varian Gemini 300 MHz,






IR Techniques: Infrared spectra were obtained on a Thermo Scientific Nicolet

6700 FT-IR.

UV-Vis Techniques: UV-vis spectra were acquired on a Hewlett Packard 8453

spectrophotometer and variable temperatures were maintained using Fisher Scientific

Isotemp 10065. Spectra were acquired in quartz cuvettes fitted with septum caps.

Electrochemical Cyclic Voltammograms Techniques: (Marie C. Corriea)

Electrochemical experiments were performed at ambient temperature in a glove box

using an EG&G PAR model 263A potentiostat/galvanostat and a three-compartment H-

cell separated by a medium porosity sintered glass frit. Electrolytic solutions consisted

of 0.1 M tetrabutylammonium hexafluorophosphate (TBAH) dissolved in either CH2Cl2

or THF. Cyclic voltammograms (CV) were recorded at 100 mVs-1 in 4 mL electrolytic

solution with 5 mM of the complex. A glassy carbon electrode (3 mm diameter) was

used as the working electrode and a platinum flag as the counter electrode. All

potentials are reported versus SCE and referenced to Ag/Ag+. The reference electrode

consisted of a silver wire immersed in a freshly prepared acetonitrile solution of 0.01 M

111

AgNO3 and 0.1 M TBAH encased in a 75 mm glass tube with a fitted Vycor tip. The Eo

values for the Fc+/Fc couple in CH2Cl2 and THF were +0.47 V and +0.58 V versus SCE

respectively.267

EPR Techniques: EPR measurements were conducted using a Bruker Elexsys-

500 Spectrometer, at the X-band, microwave frequency ~9.4 GHz in the temperature

range of 4 to 300 K. The microwave frequency was measured with a built-in digital

counter and the magnetic field was calibrated using 2,2-diphenyl-1-picrylhydrazyl

(DPPH; g = 2.0037). The temperature was controlled using an Oxford Instruments

cryostat, to accuracy within ±0.1 K. Modulation amplitude and microwave power were

optimized for high signal-to-noise ratio and narrow peaks. The EPR spectra were

acquired in a quartz capillary of approximately 1x3 mm IDxOD at room temperature

using a commercial Bruker Elexsys E580 spectrometer, equipped with a high-Q cavity

(ER 4123SHQE). General instrumental parameters are as follow: 100 kHz modulation

frequency, 0.2-1 G modulation amplitude, 0.6 mW microwave power, 9.87 GHz

microwave frequency, 20.48 ms time constant, and 81.92 ms conversion time/point.

3.4.3 Synthesis of [tBuOCO]CrVO(CH2PPh3) (6)

A 10 mL THF solution of 3 (0.153 g, 0.300 mmol) was treated with 1 equiv. of

CH2PPh3 (0.0828 g, 0.300 mmol) and stirred for 1 h. Upon addition the solution turns

red and becomes deeper red over 1 h. Pentane was added to precipitate 6, which was

filtered and washed with hexane (Yield = 81%, 0.174 g). Single crystals were grown

from a concentrated toluene solution of 6 at -35 °C. 1H NMR (300 MHz, C6D6): δ = 7.16

(br), 7.02 (s), 3.53 (s), 3.25 (br), 2.12 (s), 1.41 (s), 1.32 (s), 1.20 (s), 1.10 (s), and 0.85

(s) ppm. Selected IR bands: 3057, 2952, 2913, 2666, 1580, 1549, 1482, 1438, 1410,

112

1354, 1262, 1116, 1064, 976, 862, 779, and 747 cm-1. Anal. Calcd. for

C45H44CrO3P•(C7H8)2; C: 78.73, H: 6.72. Found; C: 78.65; H: 6.77.

3.4.4 [PPh3] vs. kobs. [tBuOCO]CrV(O)(THF) (3) in THF

Two 25 mL stock solutions of 3 (5.0 mg, 9.8 x10-6 mol) and PPh3 (70.1 mg, 2.67

x 10-4 mol) in THF were prepared. A reference cell was prepared with 0.8 mL of

chromium solution and 2.2 mL of THF. The reaction cell was prepared by adding 0.8 mL

of the chromium solution to the following volumes of THF (mL): 2.0, 1.9, 1.8, and 1.6.

The cuvette was chilled to 15 °C and the PPh3 solution was added to the reaction cell

via syringe in the respective amounts (mL): 0.2, 0.3, 0.4, and 0.6. The absorbance was

monitored at 405 nm for 300 s.

3.4.5 [OPPh3] vs. kobs. [tBuOCO]CrV(O)(THF) (3) in THF

A 25 mL THF solution of 3 (8.9 mg, 1.7 x 10-5 mol), a 25 mL THF solution of PPh3

(63 mg, 2.4 x 10-4 mol), and a 25 mL THF solution of OPPh3 (63 mg, 2.3 x 10-4 mol)

were prepared. The sample cell was prepared using 0.7 mL of the solution containing 3

with 0.0, 0.5, and 1.0 mL of the OPPh3 solution and the respective amounts of THF (1.8,

1.3, and 0.8 mL). In addition, a reference cell was prepared in a similar manner with 0.7

mL of the chromium solution with 0.0, 0.5, and 1.0 mL of OPPh3 solution but with 2.3,

1.8 and 1.3 mL of THF. The PPh3 solution (0.5 mL) was added to the sample cell via

syringe and the absorbance was monitored at 405 nm for 150 s.

3.4.6 Variable Temperature. [tBuOCO]CrV(O)(THF) in THF

A 25 mL stock solution of 3 (14.5 mg, 0.0284 mmol) in THF was prepared. In the

sample cell, 0.5 mL of the stock solution was diluted with 2.0 mL oxygen-free THF. A

reference cell was prepared in the same matter but with 0.5 mL of the stock solution

113

and 2.5 mL of oxygen-free THF. A 25 mL stock solution of PPh3 (62.6 mg, 0.239 mmol)

in THF was also prepared. 0.5 mL of the PPh3 solution was added to the reaction cell

via a syringe and the absorbance was monitored at 405 nm for 300 s. The

temperatures for the sample cells were set to 42 °C, 20 °C, 9 °C, and -2 °C; addition of

0.5 mL of the room temperature PPh3 solution resulted in a 1-2 °C change in

temperature. Every kinetic trial was allowed to go to completion before the temperature

was re-equilibrated to the initial value. Special considerations were taken for 0 °C trials

in which a nitrogen-filled atmosphere was used to prevent ice formation on the cuvette.

Also, for the 10 °C trials, periodic wiping of the cuvette was employed to avoid water

condensation.

3.4.7 Solvent Effects. OAT in MeCN, CH2Cl2, and THF

A 25 mL stock solution of 3 (16.3 mg, 0.0319 mmol) was prepared in either

MeCN, CH2Cl2, or THF. In the sample cell, 0.7 mL of the stock solution was diluted with

2.0 mL of the corresponding dry solvent (MeCN, CH2Cl2, or THF). A reference cell was

prepared in the same manner with 0.7 mL of the stock solution and 2 mL of dry solvent.

A 25 mL stock solution of PPh3 (50.5 mg, 0.193 mmol) was also prepared, and then 0.3

mL of the PPh3 solution was added to the reaction cell via syringe and the absorbance

was monitored at 405 nm for 300 s. For the CH2Cl2 samples, 50 μL of THF was added

to obtain clean isosbestic points.

3.4.8 Substrate Effects. OAT to PMe3, PPh3, and PtBu3

A 25 mL stock solution of 2 (5.0 mg, 9.78 x 10-5 mol) in THF was prepared. In the

sample cell, 0.8 mL of the stock solution was diluted with 1.7 mL THF. A reference cell

was prepared in the same manner with 2.2 mL of THF. The cells were cooled to and

114

maintained at 15°C. THF solutions of PPh3, PMe3, and PtBu3 (3.2 mM) were also

prepared. The respective phosphine solution (0.5 mL) was added to the sample cell via

syringe and the absorbance was monitored at 405 nm for 30 s for PMe3, 300 s for PPh3,

and 12 h for PtBu3.

3.4.9 [PPh3] vs kobs: OAT from {[tBuOCO]CrIV(THF)}2(μ-O ) (4) to PPh3 in CH2Cl2

Stock solutions (25 mL) of 4 (47.0 mg, 4.68 x10-5 mol) and PPh3 (43.5 mg, 1.66

x10-4 mol) in CH2Cl2 were prepared. Sample solutions were prepared using 0.25 mL of

4 by diluting with 2.25 mL, 1.75, and 0.75 mL of CH2Cl2. These solutions were treated

with 0.5, 1.0, and 2.0 mL of PPh3, respectively, via syringe and the absorbance was

monitored at 850 nm for 6 h.

115

Figure 3- 1. General mechanism for substrate oxidation that includes reversible formation of a M-O-M intermediate.

Figure 3- 2. EPR spectra (23 °C) of recrystallized [tBuOCO]CrV(O)(THF) (3) in toluene (blue, 1.29 mM) and 50:50 THF/CH2Cl2 (orange, 1.5 mM).

Figure 3- 3. Equilibrium between 3 and 3a.

116

Figure 3- 4. Normalized EPR spectra (23 °C) of 3 in toluene (red), with 1 μL THF

(green), and with 2 μL THF (blue).

Figure 3- 5. Oxygen-atom transfer reaction from 3a to PPh3.

Figure 3- 6. UV-vis spectral change of 3a in THF upon addition of PPh3 and a plot of

[3a] (0.11 mM) vs time (s) upon addition of PPh3 (1.1 mM) in THF.

0

0.5

1

1.5

2

2.5

300 400 500 600

Ab

so

rban

ce

Wavelength (nm)

0

2

4

6

8

10

12

0 50 100 150

[3a]x

10

5 (M

)

time (s)

117

Figure 3- 7. A plot of ln[3a] vs time.

Figure 3- 8. Plot depicting first-order dependency in [PPh3] (0.71 – 2.14 mM) for the OAT from 3a (0.11 mM) at 15 °C. Intercept = 0.00(±0.01) s-1; slope (k1) = 37.8(±0.7) mM-1s-1.

-14

-13

-12

-11

-10

-9

-8

0 20 40 60 80 100

ln[3

a]

time (s)

0

1

2

3

4

5

6

7

8

9

0 0.5 1 1.5 2 2.5

ko

bs x

10

2 (s

-1)

[PPh3] x103 (M)

118

Figure 3- 9. Eyring plot for the OAT from 3a (0.186 mM) to PPh3 (1.59 mM) in THF

between 0 – 40 ⁰C (R2 = 0.9875). Calculated ΔS‡ = -18(±3) cal/molK; ΔH‡ =

9.4(±0.8) kcal/mol.

Table 3- 1. Rate constants for OAT of 3a (0.30 mM) to PMe3, PPh3, and PtBu3 (0.77 mM) in THF at 15°C. –d[3a]/dt = kobs[3a] where kobs (s

-1) = k1[phosphine].

PMe3 PPh3 PtBu3

kobs (s-1

) 2.45(±0.17) x10-1 1.99(±0.14) x10-2 8.4(1.9) x10-5

Figure 3- 10. Proposed mechanism for OAT.

-19

-18

-17

-16

-15

0.003 0.0032 0.0034 0.0036 0.0038

ln (

k/T

)

1/T (K-1)

119

Figure 3- 11. Zero-order dependency on [OPPh3] (0 - 1.31 mM) in the OAT from 3a (0.163 mM) to PPh3 (1.59 mM) in THF at 22 °C.

Table 3- 2. Rate constants for OAT of 3 (2.97 x10-4 M) to PPh3 (7.70 x10-4 M) at 22 °C.

–d[3]/dt = kobs[3] where kobs = k1[PPh3].

CH2Cl2 THF MeCN

kobs (s-1

) 6.9(±1.4) x10-2 7.3(±1) x10-2 7.4(±1.1) x10-2

Figure 3- 12. Synthesis of complex 6.

0

5

10

15

20

0 0.5 1 1.5

ko

bs x

10

2 (s

-1)

[OPPh3] x103 (M)

120

Figure 3- 13. Cyclic voltammograms of 3 in CH2Cl2 (red), and 6 in CH2Cl2 (blue) in 0.1 M TBAH/CH2Cl2 at 100 mVs-1; glassy carbon working and Ag/Ag+ reference electrodes.

Figure 3- 14. Solution EPR spectrum of 6 in hexanes (black) and simulated spectrum using EasySpin.3.1.6.266 g = 1.982, A(53Cr) = 18.58 mT, A(1H) = 0.199 mT, and A(31P) = 0.066 mT.

121

Figure 3- 15. Molecular structure of [tBuOCO]CrVO(CH2PPh3) (6) drawn in two perspectives. Hydrogen atoms and two toluene lattice molecules are omitted for clarity.

Figure 3- 16. UV-vis spectral change of 4 (purple) in CH2Cl2 upon addition of PPh3 (for reference the UV-vis spectra of 2 (green) and 3 (red) in THF are included).

122

Figure 3- 17. A plot of [4] (0.16 mM) vs time (s) and ln[4] vs time upon addition of PPh3 (1.10 mM) in CH2Cl2 (22°C).

Figure 3- 18. A plot of 4 (1.56 x10-4 M) vs time upon the addition of PPh3 (1.10 – 4.42

x10-3 M) in CH2Cl2 (22 °C).

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

0 5000 10000 15000 20000

[4]

x 1

04 (

M)

time (s)

-14

-13

-12

-11

-10

-9

-8

0 5000 10000 15000 20000

ln[4

]

time (s)

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

0 5000 10000 15000 20000

[4]

x 1

04 (M

)

time (s)

[PPh3] = 1.10E-3 M

[PPh3] = 2.21E-3 M

[PPh3] = 4.42E-3 M

123

Figure 3- 19. Proposed mechanism of OAT from 43- 19 to PPh3.

124

Figure 3- 20. A plot of [4] (3.11, 1.56, and 0.78 x10-4 M) vs time (s) upon the addition of PPh3 (1.10 x10-3 M) in CH2Cl2.

Figure 3- 21. The average 2[4] – [Cr]tot ln[4] vs time for the addition of PPh3 (1.1 x10-3 M) into a 3.31 x10-4 M solution of 4 in CH2Cl2.

Table 3- 3. Simulated k1 (s

-1) and k-1 (M-1s-1) values obtained from the simulation of the

[3] vs time plots. (CH2Cl2, 22°C)

k1 (s-1) k2 (M

-1s-1) k-1 (M-1s-1)

8.37(±0.81) x10-4 69.5 1.39(±0.22) x103

0

0.5

1

1.5

2

2.5

3

3.5

0 10000 20000 30000 40000

[4]

x 1

04

time (s)

[4] = 3.11E-4 M

[4] = 1.56E-4 M

[4] = 0.78E-4 M

0.0015

0.0016

0.0017

0.0018

0.0019

0.002

0 5000 10000 15000

2 [

4]

- [[

Cr]

tot ln

[4]

time (s)

125

Figure 3- 22. Simulated (solid lines) and experimental (dotted lines) of [4] vs time at

different concentration of 4 (0.78, 1.56, and 3.11 x10-4 M).

Figure 3- 23. Absorption spectrum of 3 (2.36 x10-4 M) in CH2Cl2 (red) and after (9.1 s) addition of PPh3 (1.87 x10-3 M) to form 4 (red).

0

0.5

1

1.5

2

2.5

3

3.5

0 10000 20000 30000 40000

[4]

x 1

04

time (s)

Sim [4] = 3.31E-4 M

Sim [4] = 1.56E-4 M

Sim [4] = 0.78E-4 M

[4] = 3.11E-4 M

[4] = 1.56E-4 M

[4] = 0.78E-4 M

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

300 500 700 900

Ab

so

rban

ce

Wavelength (nm)

time = 0 s

time = 9.1 s

126

CHAPTER 4 REACTIONS OF AN ONO3- TRIANIONIC PINCER-TYPE TUNGSTEN ALKYLIDYNE

WITH ALKYNES AND NITRILES: PROBING AN UNUSUALLY STABLE

TUNGSTENABUTADIENE

4.1 Introduction

In Chapter 4, we focus our attention to improving alkyne metathesis catalysts by

using an ONO3- trianionic pincer ligand. Transition metal-catalyzed alkyne cross

metathesis,268-272,273,274-279 nitrile-alkyne cross metathesis,268, 280-287 ring-closing alkyne

metathesis,288-291 ring-opening alkyne metathesis polymerization,292-295 and acyclic

diyne metathesis296-298 generate considerable interest as useful synthetic methods to

access new RC≡CR reagents. However, considerable work is still needed to develop

catalysts that display similar activity and substrate scope tolerance as their alkene

metathesis counterparts.277, 279

The challenge to increase a catalyst’s activity lies in lowering the activation

barrier between the alkylidyne and metallacyclobutadiene intermediate (Figure 4-1).

Computational work by Jia and Lin299 examines the components to the [2+2]-

cycloaddition activation energy by a series of alkylidyne complexes featuring amido vs.

alkoxide ancillary ligands and Mo(VI) vs. W(VI) metals centers. In particular, the authors

determined for the transition state of (MeO)3W≡C(Me) that ligand deformation from a

trigonal arrangement to T-shape geometry (Figure 4-1) costs ~ 24 kcal/mol. The highly

energetic transformation is only modestly compensated by the alkyne binding (~16

kcal/mol).299 Therefore, an ideal catalyst would mitigate the ligand reorganization energy

to lower the [2+2]-cycloaddition barrier.

M. E. O'Reilly, I. Ghiviriga, K. A. Abboud and A. S. Veige, Dalton Trans., 2013, 42, 3326-3336. -Reproduced by permission of The Royal Chemical Society.

127

In addition to mitigating the activation energy for the forward and reverse [2+2]-

cycloaddition, the transformation between alkylidyne and metallacyclobutadiene

intermediates would ideally be thermoneutral. More concisely, lowering the activation

energy of the [2+2]-cycloaddition must not come at the expense of a higher barrier for

the retro-[2+2]-cycloaddition (Figure 4-2). Most importantly, the reaction must be

reversible.

The stability of a metallacyclobutadiene relative to the alkylidyne precursor is

dependent on a combination of steric and electronic contributors.300-302 Schrock and co-

workers first demonstrated that poorly basic ancillary ligands stabilize

metallacyclobutadienes.300-302 Some relevant examples are the

tungstenacyclobutadiene W(κ2-C3R3)(OR)3 with weakly basic alkoxides –

OC(CF3)2CH3,302 –OCH(CF3)2,

302 and –OC6H3(iPr)2.

301 In contrast, W(κ2-C3R3)(OtBu)3,

bearing the strongly basic alkoxide –OC(CH3)3, has never been isolated. In addition,

poorly basic alkoxides lower the [2+2]-cycloaddition activation barrier by facilitating

alkyne binding to a more electrophilic metal center.299

Using sterically cumbersome alkoxides arguably raises the energy barrier for

ligand rearrangement (trigonal T-shape) and hinders substrate access, but also

serves an important role in destabilizing the corresponding metallacylcobutadiene. For

example, W(κ2-C3Me3)(OC(CF3)2CH3)3 will metathesize 20 equiv of 3-heptyne with t1/2 <

~2.5 min in pentane or diethyl ether, but W(κ2-C3Me3)(OCH(CF3)2)3, with sterically

smaller alkoxides, only slowly converts 3-heptyne in pentane (t1/2 = 21 h).302 The slower

rate is attributable to a more stable WC3 intermediate caused by poor steric repulsion

between the alkoxides and the WC3 ring. Adding donor solvents can compensate and

128

the rate increases to t1/2 = 10 min for W(C3Me3)(OCH(CF3)2)3 in Et2O. Interestingly, ΔS‡

for the retro-[2+2]-cycloaddition of W(κ2-C3Et3)(OCH(CF3)2)3 is consistent with an

associative transition state.302

Our strategy to improve alkyne metathesis employs trianionic pincer ligands that

are rigid and pre-organized to adopt a T-shape. Using a trianionic pincer ligand

eliminates the costly ancillary ligand rearrangement energy during the [2+2]-

cycloaddition described by Jia and Lin299 and will also allow large substrates access to

the metal center.

Our initial approach was to synthesize a tungsten alkylidyne supported by a

trianionic OCO pincer ligand. However, the tungsten alkylidyne carbon is susceptible to

insertion into the pincer C-W bond.59 Switching to a trianionic ONO pincer-type ligand

should prevent any potential insertion chemistry. The [CF3-ONO]3- ligand depicted in

Figure 4-3 incorporates a push-pull279, 295, 303-306 electronic environment created by

pairing an electron-rich amido with fluorinated alkoxides, which is well-known to

enhance the activity of alkyne metathesis catalyst.302

Here, we report the synthesis of the neutral ONO3- trianionic pincer-type tungsten

alkylidyne complex [CF3-ONO]W≡CtBu(OEt2) (18). Moreover, as expected, complex 18

reacts rapidly with alkyne substrates PhC≡CMe, tBuC≡CMe, and cyclooctyne to yield

their respective metallacycles. The cyclooctyne derivative is the first example of a

bicyclic metallacyclobutadiene. However, the tungstenacyclobutadienes are remarkably

stable and the WC3 doesn’t cleave under strenuous conditions. Presented below are

their synthesis and characterization, and a discussion regarding the factors promoting

their stability.

129


4.2.1 Synthesis and Characterization of [CF3-ONO]H3 (8)

Our initial approach to preparing an [CF3-ONO] ligand involved treating bis(2-

bromophenyl)amine with three equivalents of nBuLi followed by hexafluoroacetone

addition (Figure 4-4). However, the product could not be realized from a mixture of

products. A potential problem was that hexafluoroacetone would undergo electrophilic

aromatic substitution at the para-position. As such, we decided to protect the para-

position with a methyl substituent.

Preparing the ligand precursor [CF3-ONO]H3 (8) involves treating bis(2-bromo-4-

methylphenyl)amine307 with 3.1 equiv of nBuLi in Et2O and then adding

hexafluoroacetone at -78 °C (Figure 4-5). Warming to 25 °C and an acidic workup yields

isolable proligand 8 in 35% yield. In the 19F{1H} NMR spectrum of 8 (CDCl3), two broad

multiplets attributable to the fluorine atoms appear at -76.3 and -74.9 ppm. The fact two

signals appear indicates a slow rotation around the aryl‒C(CF3)2OH bond at 25 °C.

Coalescence of the signals occurs upon heating a sample of 8 to 45 °C in an NMR

probe. Routine 1H and 13C{1H} NMR spectroscopic techniques corroborate the identity

and purity of 8 (Appendix). Notable features in the 1H NMR spectrum include a singlet at

2.36 ppm for the aryl-methyl protons, and a broad resonance spanning from 7.0 to 7.5

ppm that corresponds to the protons of the amine and the two alcohol groups.

4.2.2 Synthesis and Characterization of [CF3-ONO]W=CH(tBu)(OtBu) (9)

Treating [CF3-ONO]H3 (1) with (tBuO)W≡CtBu308 in benzene yields complex 9, a

tungsten alkylidene supported by a [CF3-ONO]3- pincer-type ligand (Figure 4-6).

Complex 9 crystallizes from a pentane solution at -35 °C. The 1H NMR spectrum of 9

exhibits protons at 1.15 and 1.24 ppm attributable to the W=CHC(CH3)3 and OC(CH3)3

130

protons, respectively. The W=CHtBu proton resonates at 6.44 ppm with 2JHW = 8.80 Hz,

and the corresponding carbon signal appears at 262.6 ppm in the 13C{1H} NMR

spectrum. The aryl rings of [CF3-ONO]3- are unable to lie coplanar rendering the

complex C1-symmetric as exemplified by two separate Ar-CH3 proton resonances at

1.99 and 1.94 ppm. As a further consequence of the C1-symmetry, the 19F{1H} NMR

spectrum of 9 contains four quartets, one for each –CF3 group, at -70.7, -71.5, -73.4,

and -77.3 ppm.

4.2.3 Synthesis and Characterization of {[CF3-ONO]W≡C(tBu)(OtBu)}{MePPh3} (10)

Treating a pentane solution of 9 with Ph3PCH2 deprotonates the alkylidene and

precipitates the anionic alkylidyne, complex 10, as an analytically pure pink powder

(Figure 4-7). The 1H NMR spectrum of 10 contains a doublet at 2.36 ppm (2JHP = 13.31

Hz) corresponding to the H3CPPh3+ counter cation, and the 31P{1H} spectrum contains a

single peak at 21.6 ppm. The W≡CtBu carbon resonates downfield in the 13C{1H} NMR

spectrum at 286.0 ppm; and again the 19F{1H} NMR spectrum reveals the characteristic

four quartets indicative of C1-symmetry at -68.7, -71.2, -74.4, and -76.2 ppm.

4.2.4 In-situ Synthesis of {CH3PPh3}{[CF3-ONO]W≡CtBu(OTf)} (11) and [CF3-ONO]W≡C(tBu)(OEt2) (12)

Upon treating a benzene solution of complex 10 with excess methyl triflate, a

color change from red to deep blue occurs over 0.5 h. Evaporating the solvent under

vacuum yields a deep blue oil, which was further purified by dissolving in a minimal

amount of benzene and adding dropwise to a cold pentane solution to deposit a deep

blue oil of 11. Unfortunately, some decomposition occurs, and free [CH3PPh3][OTf]

cannot be removed (Figure 4-8). Nonetheless, 1H, 19F{1H}, and 2D NMR spectra

unambiguously confirm the identity of 11. The 1H NMR spectrum displays one tBu

131

proton resonance at 1.07 ppm and two Ar-CH3 proton resonances at 2.10 and 2.07

ppm. The 19F{1H} NMR spectrum of 11 contains four quartets at -69.0, -73.2, -73.9, and

-76.7 ppm, and two additional singlet resonances at -76.7 and -78.2 ppm corresponding

to coordinated and free –OSO2CF3 anions. The W≡CtBu carbon appears at 309.4 ppm

in the 13C{1H} NMR spectrum. For practical reasons, the isolation of 11 is not necessary,

since dissolving blue 11 in Et2O yields a light blue solution of 12 and a colorless

precipitate of [CH3PPh3][OTf] (Figure 4-8). The majority of the [CH3PPh3][OTf] can be

removed initially by filtration, and a small amount precipitates in Et2O at -35 °C.

However, variable amounts of [CH3PPh3][OTf] always remain during bulk scale

synthesis of 12, thus thwarting combustion analysis.

The 1H NMR spectroscopic characterization of 12 reveals one coordinated Et2O

molecule. The -CH2- protons of the coordinated ether are diastereotopic, appearing as

two multiplets at 3.83 and 3.64 ppm. The tBu protons resonate at 0.84 ppm, and the two

Ar-CH3 protons appear at 2.04 and 2.06 ppm. The 19F{1H} spectrum displays the

prototypical quartets at -69.2, -71.8, -75.4, and -77.2 ppm. The signal from the W≡CtBu

carbon appears downfield at 311.5 ppm in the 13C{1H} NMR spectrum.

Blue crystals of 12 co-crystallize with residual [CH3PPh3][OTf] by slowly

evaporating a concentrated Et2O solution of the mixture. Depicted in Figure 4-9 is the

solid state structure of 12. The alkylidyne 12 contains a tungsten(VI) ion in a square

pyramidal geometry (τ = 0.266),194 with the [CF3-ONO]3- ligand and the coordinated

Et2O occupying the basal positions (Figure 4-9). The alkylidyne bond sits in the apical

position and is nearly linear (W1-C21-C22 is 171.2(2)°) with a W1-C21 bond length of

1.754(3) Å, consistent with other W≡C bond lengths ranging between 1.745 - 1.838 Å

132

for neutral W(VI) alkylidynes.295, 300, 304, 305, 309-322 The C1-symmetry of 18 is apparent in

Figure 4-9 by the underlying twist of the [CF3-ONO]3- ligand. The nitrogen atom, N1,

adopts a planar sp2 hybridized geometry, evidenced by a 358.8(3)° sum of angles

around N1. The vector perpendicular to the C3-N1-C13 plane representing the nitrogen

lone pair forms a ~45° angle from parallel with the W≡C bond.

4.2.5 Synthesis and Characterization of [CF3-ONO]W[κ2-C(tBu)C(Me)C(Ph)] (13)

Complex 12 (or 11 generated in situ) readily reacts with excess PhC≡CCH3 to

yield the tungstenacyclobutadiene complex 13 (Figure 4-10). The 1H NMR spectrum of

13 contains the WC3-CH3 protons at 2.79 ppm. The protons of the tBu group shift to

1.21 ppm and the WC3-C6H5 protons appear between 7.02 and 7.13 ppm. Complex 13

is C1-symmetric yielding four quartets in the 19F{1H} NMR at -71.5, -72.1, -76.1, and -

76.5 ppm, and the 13C{1H} NMR contains two W-Cα resonances at 245.4 and 243.0

ppm.

Crystals were initially grown by slowly evaporating a diethyl ether solution of 13.

However, crystals more suitable for an X-ray diffraction experiment were obtained from

a slowly evaporating pentane solution of 13. Table 4-1 and Table 4-2 list pertinent bond

length and angel data. The solid state structure of 13, presented in Figure 4-11,

contains a tungsten atom in a distorted-square pyramidal geometry (τ = 0.097)194 with

the CtBu (C21) occupying the apical position. The W1-C21 and W1-C23 bond distances

are 1.9046(16) Å and 1.9106(18) Å, respectively, which are consistent with other

reported WC3 rings (Figure 4-12). Quite interesting is that the two W-C bond lengths are

nearly equal, with a difference of only 0.006(3) Å, whereas other reported structures

display a larger difference between the W-Cα bonds, ranging from 0.023 to 0.113 Å

(Figure 4-12). The W1-N1 bond distance is 2.0158(14) Å and the vector perpendicular

133

to the C3-N1-C13 plane representing the nitrogen lone pair forms an angle of 42.26° to

the WC3 plane.

The phenyl ring (C29-C34) attached to the WC3 ring is forced 44.65° from

collinearity with the WC3 plane. This may be attributed to steric interactions from the

nearby WC3-CH3 group (C28). An interesting structural feature arising from the

constrained pincer-type geometry is the O1-W1-O2 angle of complex 13 is tied-back

resulting in an angle of 147.78(5)°, which is significantly more acute (10° - 18°) than

other crystallographically characterized tungstenacyclobutadienes (Figure 4-12).301, 302,

305, 323 Overall, the WC3 ring of complex 13 contains similar structural features to the

other reported WC3 ring moieties depicted in Figure 4-12.

To our surprise, complex 13 does not react further with PhC≡CCH3 to yield any

cross-metathesis products, even after heating at 200 °C, with Et2O as a free donor

ligand. Despite the seemingly similar electronic features of the [CF3-ONO]3- ligand and

structural components of the WC3 ring to reported alkyne metathesis catalysts, complex

13 does not undergo retro-[2+2]-cycloaddition. Something unique to the [CF3-ONO]3-

pincer-type ligand must render the tungstenacyclobutadiene fragment exceptionally

stable. One possibility is the pincer-type ligand, being overly rigid, may prevent the

fluxional exchange between the apical and equatorial positions within the WC3 ring as

illustrated in Figure 4-13. The solid state structure of 13 contains only a single

conformer, where tBu occupies the apical position, but does the [CF3-ONO]3- ligand

allow a conformer change in solution? Since complex 13 contains different groups in

position R1 and R3, it is impossible to determine if a fluxional process occurs in solution.

134

However, if the process is fluxional and R1 = R3 = tBu, a single resonance should be

present in the 1H NMR spectrum.

4.2.6 Synthesis and Characterization of [CF3-ONO]W[κ2-C(tBu)C(Me)C(tBu)] (14)

Heating complex 12 in the presence of tBuC≡CMe in C6H6 at 60 °C for 3 h yields

complex 14 where R1 and R3 contain the same tBu appendage (Figure 4-10). Single

crystals suitable for X-ray diffraction experiments were grown by slowly evaporating an

Et2O solution of 14. Table 4-1 and Table 4-2 list pertinent bond lengths and angles and

Figure 4-14 depicts the molecular structure. Complex 14 is C1-symmetric with the

tungsten atom again in a distorted square pyramidal geometry (τ = 0.111).194 The

refined X-ray data contains a slight disorder (7%) in the tungsten position. A salient

feature in the solid state structure is that the tBu groups are not equivalent. Evidence

includes different W-C bond lengths for W1-C21 = 1.882(3) Å and W1-C23 = 1.908(3)

Å, and different N-W-C bond angles (N1-W1-C21 = 122.65(10)° and N1-W1-C23 =

154.02(10)°). However, the asymmetry only exists in the solid state, because the 1H

NMR spectrum of 14 exhibits a single resonance for both tBu groups at 1.19 ppm,

affirming a fluxional process between the two conformers. The rapid exchange in

solution produces an overall C2-symmetry as evidenced in the 19F{1H} NMR spectrum of

14, which exhibits only two quartets at -71.9 and -76.5 pm. Similarly, the 13C{1H} NMR

spectrum contains only a single resonance for both Cα in the WC3 ring at 252.8 ppm.

Despite the increased steric bulk within the WC3 ring compared to 13, complex 14 again

does not react with additional PhC≡CMe, even at 200 °C in the presence of Et2O.

135

4.2.7 Synthesis and Characterization of [CF3-ONO]W[κ2-C(tBu)C(CH2(CH2)4CH2)C] (15)

If thermolysis does not provide the energy necessary to cleave the WC3 ring, an

internal driving force that weakens the WC3 ring may be necessary. Treating complex

12 with cyclooctyne in C6H6 provides complex 15, which contains a WC3 ring fused to a

cyclooctene (Figure 4-10). The internal ring strain within cyclooctene contributes 7.4

kcal/mol324 directed towards destabilizing the WC3 unit. The 1H NMR spectrum of 15 is

indicative of a C1-symmetric complex with six aromatic resonances at 7.69 (s), 7.61 (s),

7.12 (d), 7.10 (d), 6.88 (d), and 6.85 (d) ppm. The Ar-CH3 resonances appear at 2.05

and 2.01 ppm and the tBu protons resonate at 1.18 ppm. Within the fused cyclooctene

structure, the two –CH2– protons adjacent to the WC3 ring are diastereotopic appearing

as four multiplets at 3.82, 3.66, 3.36, and 3.18 ppm. The remaining –CH2– protons (8H)

appear as several broad resonances between 0.90 and 1.55 ppm. The 19F{1H} NMR

spectrum contains four quartets at -70.9, -72.2, -76.1, and -76.6 ppm, and the 13C{1H}

spectrum exhibits two unique resonances for W-Cα atoms at 252.8 and 238.6 ppm.

Single crystals grow from slow evaporation of a concentrated Et2O solution of 15.

Table 4-1 and Table 4-2 list pertinent bond lengths and angels and Figure 4-15 depicts

the molecular structure of 15. The solid state structure consists of a distorted square

pyramidal tungsten ion. Attached to the WC3 ring is a tBu group (C24-27) and a fused

cyclooctene ring (C28-C32). The cyclooctene ring is disordered, containing two different

conformations at C30 and C31. The CαtBu again occupies the apical position and forms

a 123.66(10)° bond angle with N1 of the pincer-type ligand (N1-W1-C21) while the

adjacent N1-W1-C23 bond angle is 153.22(10)°. The apical W1-C21 bond length of

1.911(3) Å is slightly longer by 0.014(4) Å than the W-C23 bond length of 1.897(3) Å.

136

Overall the bond lengths and angles about the WC3 ring within complexes 13, 14, and

15 are comparable (Table 4-1 and Table 4-2).

Despite the strain imposed by the fused cyclooctene ring, treating complex 15

with excess PhC≡CMe and diethyl ether at 200 °C in toluene-d8 does not yield

metathesis products. One salient feature within the molecular structures of 13, 14, and

15 is the acute O1-W1-O1 bond angles of 147.78(5)°, 147.39(8)°, and 147.80(7)°,

respectively. As a result of this acute angle and the overall pincer-type architecture, the

-CF3 groups are tied back and prevented from exerting steric pressure on the

tungstenacyclobutadiene ring. In contrast are the crystallographically characterized

tungstenacyclobutadiene of active alkyne metathesis catalysts (Figure 4-12, structures

A, C, and D), where the large ancillary ligands reside over the WC3Et3 ring. As

mentioned earlier, the stability of the metallacyclobutadiene complexes depends on the

steric repulsion between the ancillary ligand and the substituents attached to the WC3

ring. Consequently, these isolated structures feature small ethyl substituents attached to

the tungstenacyclobutadiene ring to minimize the destabilizing steric repulsion. Despite

complexes 13-15 containing larger tBu substituents, the WC3 ring is exceptionally inert.

For complexes 13, 14, and 15, the closest distances between the -CF3 of the pincer-

type ligand and the WC3-R groups (R = tBu, Ph, -C6H12-) are 3.54, 3.52, and 3.53 Å,

respectively. For complex A (Figure 4-12), the closest contact between the -CF3 and the

-Et group is 3.11 Å.305

Considering the poor steric pressure from the [CF3-ONO] ligand on the WC3R3

rings of 13, 14, and 15, perhaps adding a stronger donor ligand (e.g. PMe3) will promote

retro-[2+2]-cycloaddition similar to adding Et2O to W(C3Me3)(OCH(CF3)2)3.302 Treating

137

complexes 13-15 with excess PhC≡CMe and PMe3, as a potential strong σ-donor

ligand, at 100 °C did not generate any metathesis products. Interestingly, a C6D6

solution of complex 13 turns violet upon addition of PMe3, accompanied by a

broadening of protons resonances in the 1H NMR, but slowly decomposes in solution.

The 1H NMR spectra of complexes 14 and 15 displayed no signs of reaction with PMe3.

The unusual stability of complexes 13-15 prompted us to investigate a possible

electronic component to the apparent energetic disparity between 13, 14, and 15 and a

putative alkylidyne.

4.2.8 Computational Studies

Figure 4-16 depicts the geometry optimized structure of both 12 and 13, as

calculated by DFT methods. For complex 12, the calculated bond lengths and angles of

the tungsten ion core are in good agreement with the crystallographically determined

values. For example, the W1-C21-C22 bond angle of 172.35° matches the experimental

value of 171.2(2)°. Similarly, the O1-W1-O2 angle of 143.64° agrees with the

experimental value of 144.97(8)°. The vector perpendicular to the C3-N1-C13 plane

representing the nitrogen lone pair is 42.42° from parallel with the tungsten alkylidyne

bond (W1-C21). This angle is slightly more acute than the experimental angle of 45°.

The calculated metric parameters for complex 13 are also reasonable, although

some bond angle differences deserve mentioning. The N1-W1-C21 angle of 129.77° is

6.78° larger than the crystallographic determined angle of 122.99(7)°. Correspondingly,

the adjacent angle, N1-W1-C23, of 148.39° is smaller by 5.21° than the experimental

value of 153.60(6)°. These deviations are not uncommon and are observed for other

reported WC3 structures.304, 305 A more significant deviation is the O1-W1-O2 angle of

155.13° from the experimental angle of 147.78(5)°. In agreement though, the nitrogen

138

lone pair represented by a vector perpendicular to the C3-N1-C13 plane forms a 42.75°

to the WC3 ring, matching the experimentally value of 42.26°.

Quite interesting the molecular structure of 12 from single crystal X-ray diffraction

(Figure 4-9) and DFT geometry optimization (Figure 4-17) contain an irregular amido

orientation. More precisely, the nitrogen lone pair is prevented from aligning with the

low-lying dxy orbital perpendicular to the W≡C bond. Instead, the rigid pincer scaffold

constrains the nitrogen lone pair orientation ~45° from parallel to the W≡C π-bond. The

Gaussian single point calculation of complex 12 (Figure 4-17) reveals a unique bonding

interaction between the tungsten alkylidyne π-bond and the nitrogen lone pair, that

resembles the electronic bonding structure of enamines. In our case, an inorganic

version of the enamine, the alkylidyne π-bond facing the nitrogen (HOMO-2) displays

overlap with the nitrogen’s lone pair, lowering its energy by 0.01822 AU relative to the

adjacent π-bond HOMO-1. Conversely, the nitrogen lone pair in the HOMO forms a

destabilizing anti-bonding interaction with the alkylidyne π-bond. The electronic

consequence of an inorganic enamine will be further discussed in Chapter 5, but similar

to enamines, the nitrogen lone pair serves to increase the nucleophilicity of the

alkylidyne α-carbon.

To assess the interaction of the inorganic enamine in 12 and its fate upon [2+2]-

cycloaddition and possible role in preventing retro-[2+2]-cycloaddition, Gaussian single

point calculations were performed on 13. Figure 4-17 depicts a truncated molecular

orbital diagram of 12 with the inorganic enamine interaction and the frontier MO of 13.

Analysis of the electronic structure of 13 reveals that the inorganic enamine

bonding combination within 12 is lost. From the single point calculations of 13, the

139

nitrogen lone pair (HOMO) is lower in energy than the HOMO of 12 by 0.0155 AU,

while the W-C π-bonds of 13 and 12 retain similar energy levels (-0.22214 and -

0.22268 AU, respectively). The N-atom lone pair is essentially non-bonding. The LUMO

consists of the π* interaction between the dxy orbital and p-orbitals of the WC3 ring. The

HOMO-1 contains a dyz orbital in π-overlap with the two Cα p-orbitals of the WC3 ring.

This WC3 π-bonding interaction is consistent with other theoretical models.325-330 The

HOMO-1 also shows a small amount of bonding overlap with the nitrogen p-orbital,

though it is unclear whether this interaction contributes much to the stability of 13. The

most important feature is the restricted orientation caused by chelation, the nitrogen

lone pair does not π-donate into the LUMO which would destabilize the WC3 ring by

populating a π* orbital.

4.2.9 15N NMR Studies

The drastic changes in the nitrogen bonding environment from the alkylidyne

complexes of 10-12 and the tungstenacyclobutadiene complexes 13-15 are evident by

15N NMR spectroscopy. Table 4-3 lists the 15N resonances for complexes 9-15 (C6D6).

The N-atom lone pair in the alkylidene complex 9 does not have the appropriate

orientation to overlap with the W=C bond, and as a consequence the lone pair is

essentially non-bonding.53 The 15N resonance for 9 appears downfield at 225.7 ppm. In

contrast, the 15N resonance shifts dramatically upfield to 149.3, 165.5, and 178.3 ppm

upon forming the W≡C triple bonds in 10, 11 and 12, respectively. Clearly, the N-lone

pair experiences a new environment, which involves overlap with the W≡C bond. This

dramatic change in the 15N NMR chemical shift provides experimental evidence for an

inorganic enamine orbital interaction. The interaction is lost upon [2+2]-cycloaddition to

form 13, 14, and 15. From the calculated electronic structure of 13, the N-atom lone pair

140

is essentially non-bonding, and consequently the 15N resonance reverts back downfield

to 208.6 ppm. Similarly, tungstenacycloabutadienes 14 and 15 also exhibit downfield

signals at 204.4 and 202.1 ppm, respectively.

4.2.10 Electronic Factors Contributing to an Irreversible [2+2]-Cycloaddition

The thermodynamic irreversibility of the [2+2]-cycloaddition products 13, 14, and

15 is astonishing. As mentioned earlier, complexes 13-15 lack significant steric

repulsion between the ancillary ligand and the WC3R3 ring. Unlike the example of W(κ2-

C3Me3)(OCH(CF3)2)3, where poor sterics were compensated for by adding Et2O,302

adding a strong σ-donating PMe3 ligand was not sufficient to break apart the WC3 ring.

Moreover, these results are intriguing since the [CF3-ONO]3- ligand incorporates similar

electronic features to the fluorinated alkoxides paired with an amido donor, utilized in

Tamm’s highly active catalysts.279, 295, 303-305, 322 This leads us to think another factor

plays a significant part in the overly stable tungstenacylobutadienes 13, 14, and 15.

Figure 4-18 depicts the [CF3-ONO]3- pincer-type ligand where the amido lone pair

is 45° from parallel to the tungsten alkylidyne bond (I). For comparison, also depicted

are Tamm’s active catalysts, in which the amido ligand lone pair either freely rotates

(Figure 4-18; II)304, 305 or is restricted (Figure 4-18; III).304 In both II and III, the nitrogen

lone pair orients perpendicular to the tungsten-alkylidyne bond, thus avoiding the

inorganic enamine interaction. In case II, where the imidazolin-2-iminato ligand can

freely rotate, the nitrogen lone pair reorients 90° upon [2+2]-cycloaddition to lie coplanar

to the WC3 ring.304, 305 In the case of III, the computational models predict that the

bulkier tert-butyl-3,5-(dimethylphenyl)amido ligand is unable to rotate, remaining

perpendicular to the WC3 plane.304 Both II and III undergo retro-[2+2]-cycloaddition.

141

Thus, one electronic difference between I and cases II and III, is II and III are able to

avoid the unfavourable inorganic enamine.

4.2.11 Nitrile-Alkyne Cross Metathesis

As retro-[2+2]-cycloaddition occurs, the amido-alkylidyne interaction turns on

according to Figure 4-19 and is endergonic. Removing the amido-alkylidyne interaction

should permit facile retro-[2+2]-cycloaddition. One way to do this is to attempt Nitrile-

Alkyne Cross Metathesis (NACM). Upon formation of an azametallacyclobutadiene,

retro-[2+2]-cycloaddition would provide a W≡N bond instead of a W≡C, which would not

have the correct energy match to overlap with the N-atom lone pair, and moreover, the

W≡N bond formation should make the overall reaction exergonic. Importantly, the

sterics remain the same if not somewhat reduced, since the nitrile-N-atom does not

bear a substituent.

Indeed, treating complex 12 with excess acetonitrile in C6D6 yields a 57:43

mixture of free 4,4-dimethyl-2-pentyne and 14 along with unidentifiable species (Figure

4-20) as evidenced by 1H NMR. 4,4-Dimethyl-2-pentyne is removed by vacuum and the

1H and 19F{1H} NMR spectra unambiguously confirm the identity of 14. The

unidentifiable products are presumably tungsten nitrido species, though the identity is

not clear from the spectroscopic data. Broad resonances in the 1H and 19F{1H} NMR

spectra of the reaction mixture may represent several multi-nuclear species; it is well-

known for W-nitrido complexes to exist as dimers,287, 331-334 trimers,332-335 and larger

oligomers.332, 333 Most importantly, complex 14 and the free 4,4-dimethyl-2-pentyne

indicate retro-[2+2]-cycloaddition occurred. In fact, retro-[2+2]-cycloaddition must occur

swiftly because 14 is the product of alkylidyne 12 and free 4,4-dimethyl-2-pentyne.

142

Adding excess tBuC≡CMe to the reaction mixture does not result in any further nitrile-

alkyne cross metathesis from the presumed tungsten-nitrido species.

4.3 Conclusion

Presented is the synthesis of a neutral trianionic pincer-type tungsten alkylidyne

(12). Complex 12 reacts with PhC≡CMe, tBuC≡CMe, and cyclooctyne to form

tungstenacyclobutadiene complexes 13, 14, and 15, respectively. Notably, the synthesis

of complex 14 demonstrates the potential advantage of using a trianionic pincer-type

ligand. Namely, sterically cumbersome alkyne (tBuC≡CMe) can access the metal center

to form the metallacyclobutadiene intermediate at a reasonably low temperature (60

°C). Also, complex 15 is the first example of a bicyclic metallacyclobutadiene, which is

quite remarkable considering cyclooctyne is typically polymerized as a consequence of

its internal ring strain.294, 336, 337 The tungstenacyclobutadienes 13-15 contain bond

angles and lengths that are similar to reported single crystal X-ray structures of

metallacyclobutadienes from active metathesis catalysts. Regardless of similarities, the

complexes 13, 14, and 15 do not undergo retro-[2+2]-cycloaddition to regenerate the

alkylidyne, even at 200 °C.

Both steric and electronic features push the thermodynamic stability towards 13,

14, and 15 from the corresponding alkylidyne. Notably, the chelating nature of the

pincer ties back the pendant perflouroalkoxides, preventing the CF3 groups from

exerting steric pressure on the WC3 core. Surprisingly, adding excess donor ligands

such as Et2O and PMe3 doesn’t compensate for the poor steric pressure, further

supporting an electronic hindrance to retro-[2+2]-cycloaddition.

DFT calculations reveal the key electronic features within complexes 12 and 13.

Within complex 12, the N-atom lone pair on the pincer forms a bonding and anti-

143

bonding interaction with the W≡C π bond resembling an enamine. Evidence for

enamine bonding interaction between N-atom lone pair and the alkylidyne π-bond

comes from 15N NMR spectroscopy. The 15N resonance shifts upfield by 47 ppm upon

forming the inorganic enamine in the alkylidyne complex 12 (178.3 ppm) from the

starting alkylidene complex 9 (225.7 ppm). The inorganic enamine interaction is lost

upon forming the tungstenacyclobutadiene 13, and the 15N NMR resonance reverts

back downfield to 208.6 ppm.

Evidence supports that the inorganic enamine interaction is a substantial

electronic impediment preventing a reversible [2+2]-cycloaddition. Proof to support this

claim comes from the nitrile-alkyne cross metathesis by complex 12 with acetonitrile.

Retro-[2+2]-cycloaddition from the azatungstenacyclobutadiene intermediate forms a

stable W≡N bond, which is unable to participate in an inorganic enamine bonding

combination.

Additional support comes from Tamm’s catalysts.295, 303-305, 322 Both complexes II

and III (Figure 4-18) contains a similar electronic environment of fluorinated alkoxide

and amido ligands. However, the inorganic enamine bonding combination is not

present, and consequently they are active catalysts.

Often in chemical research, a ligand purposely designed for a specific application

may in fact be incompatible for the process. However, the [CF3-ONO] ligand may be

suitable for other applications as featured in Chapter 5. Nevertheless, these results give

us useful information to the design of more appropriate ligands. To remedy these

problems associated with [CF3-ONO] pincer-type ligand, current work presented in

Chapter 6 features a newly designed ONO ligand to destabilize the

144

metallacyclobutadiene by increasing the peripheral steric bulk and avoiding any

inorganic enamine interactions.

4.4 Experimental



atmosphere using standard Schlenk or glove-box techniques. Pentane, hexanes,

toluene, diethyl ether, tetrahydrofuran, and acetonitrile were dried using a GlassContour

drying column. Benzene-d6 and toluene-d8 (Cambridge Isotopes) were dried over

sodium–benzophenone ketyl, distilled or vacuum transferred and stored over 4Å

molecular sieves. (tBuO)W≡CtBu,308 cyclooctyne,338 and Ph3PCH2339 were prepared

according to published procedures.


NMR Techniques: 1H, 13C{1H}, and 2D NMR spectra were obtained on an Inova

500 MHz, and the 19F{1H} and 31P{1H} were acquired on a Varian Mercury Broad Band

300 MHz or Varian Mercury 300 MHz spectrometers. Chemical shifts are reported in δ

(ppm). For 1H and 13C{1H} NMR spectra, the residual solvent peak was used as an

internal reference.

Elemental Analysis: Elemental analyses were performed at Complete Analysis

Laboratory Inc., Parsippany, New Jersey.

4.4.3 Calculations

Geometry optimization, single point analysis, and vibration frequency analysis of

12 and 13 were performed using spin-restricted density functional theory calculations,

using a hybrid functional B3LYP219, 340and LANL2DZ341 basis as implemented in the

Gaussian 03 program suite.218 The atomic coordinates from the crystal structures were

145

used as an initial input for the geometry optimized structures. Molecular orbital pictures

were generated from Gabedit342 at their reported isovalues.

4.5.4 Synthesis of 2,2'-(azanediylbis(3-methyl-6,1-phenylene))bis(1,1,1,3,3,3-

hexafluoropropan-2-ol) (8)

Inside a nitrogen-filled glovebox, an n-butyl lithium solution (10.9 mL, 2.5 M, 27.3

mmol) was added drop-wise to a Schlenk-flask containing a solution of bis(2-bromo-4-

methylphenyl)amine (3.103 g, 8.79 mmol) in diethyl ether (30 mL) at -35 °C. The

reaction mixture was stirred for 2 h while warming to room temperature. The reaction

flask was fitted with a dry ice condenser before exiting the box. The reaction flask was

connected to the schlenk line through the port on the dry ice condenser. The reaction

solution was cooled to -78 °C, and dry ice and acetone were added to the condenser.

Hexafluoroacetone was condensed at -78 °C (5 mL, 6.6 g, 39 mmol) into a separate

pressure flask. The pressure flask was connected to the reaction flask via the side-arm.

The pressure flask was allowed to slowly warm to room temperature causing the

hexafluoroacetone to evaporate slowly and condense into the reaction flask. After

complete transfer, the pressure flask was removed. The reaction mixture was allowed to

warm to room temperature while keeping the dry ice/acetone condenser filled (the

hexafluoroacetone will condense on the cold finger and drip back into the solution). The

reaction mixture was stirred for at least 3 h before allowing the dry ice/acetone to expire

and the excess hexafluoroacetone leaves through the schlenk manifold. Addition of HCl

in Et2O (27.3 mL, 1 M) precipitated LiCl from the red solution. The solution was filtered,

and the filtrate was reduced to a thick oil. The thick oil was placed under vacuum for two

hours, followed by adding hexanes to precipitate the product. The lightly pink powder

was filtered and dried (1.66 g, 35% yield). 1H NMR (CDCl3, 300 MHz, 25 °C): δ = 7.5-

146

7.0 (b, 3 H, NH and 2 OH), 7.37 (s, 2H, Ar-H), 7.17 (d, 2H, 3J = 8.35 Hz, Ar-H), 8.83 (d,

2H, 3J = 8.35 Hz, Ar-H), and 2.36 (s, 3H, CH3) ppm. 19F{1H} NMR (CDCl3, 300 MHz, 25

°C) : δ = -74.9 (b) and -76.3 (b) ppm. 13C{1H} NMR (CDCl3, 300 MHz, 25 °C): δ = 142.8

(s, Ar C), 134.3 (s, Ar C), 132.1 (s, Ar C), 128.5 (s, Ar C), 126.0 (s, Ar C) , 120.78 9 (s,

Ar C), and 21.0 (s, CH3) ppm. 13C{19F} NMR(CDCl3): δ = 122. 8 (s, CF3) and 80.3 (s,

Ar(CF3)2COH) ppm. ESI-MS: 530.0984 [1+H]+, 552.0803 [1+Na]+, and 574.0623 [1-

H+2Na]+.

4.4.5 Synthesis of [CF3-ONO]W=CHtBu(OtBu) (9)

A benzene solution (1 mL) containing 8 (0.324 g, 6.11 x10-4 mol) was added

drop-wise to a benzene (1 mL) solution of (tBuO)W≡CtBu (0.289 g, 6.11 x10-4 mol). The

reaction mixture was allowed to stir for 1 h before evaporating all volatiles under

vacuum for 4 h. The brownish-red powder was dissolved in pentane and filtered. The

filtrate was collected and concentrated to 3 mL. Cooling the solution to -35 °C yields

crystals of 9. A second batch of crystals was obtained after further concentrating and

once again cooling the solution to -35 °C. Total yield is 0.350 g (66 %). 1H NMR (C6D6):

δ = 7.71 (s, 1H, Ar-H), 7.69 (s, 1H, Ar-H), 6.82 (d, 1H, Ar-H, 3J = 8.21 Hz), 6.66 (d, 1H,

Ar-H, 3J = 8.50 Hz), 6.57 (d, 2H, Ar-H, 3J = 8.50 Hz), 6.44 (s, 1H, W=CHtBu, 2J(1H,

183W) = 8.80 Hz), 1.99 (s, 3H, Ar-CH3), 1.94 (s, 3H, Ar-CH3'), 1.24 (s, 9H, OC(CH3)3),

and 1.15 (s, 9H, WCHC(CH3)3) ppm. 19F{1H} NMR (C6D6): δ = -70.71 (q, 3F, -CF3, 4J =

8.48 Hz), -71.52 (q, 3F, -CF3, 4J = 10.90 Hz), -73.44 (q, 3F, -CF3,

4J = 10.90 Hz), and -

77.31 (q, 3F, -CF3, 4J = 8.48 Hz) ppm. 13C{1H} NMR (C6D6): δ = 262.6 (s, WCHtBu),

146.5 (s, Ar C), 145.4 (s, Ar C), 134.4 (s, Ar C), 133.6 (s, Ar C), 133.0 (s, Ar C), 131.0

(s, Ar C), 127.5 (s, Ar C), 127.3 (s, Ar C), 126.2 (s, Ar C), 123.9 (s, Ar C), 123.5 (s, Ar

C), 90.4 (s, OCMe3), 41.0 (s, WCHC(CH3)3), 35.0 (s, WCHC(CH3)3), 29.2 (s, OC(CH3)3),

147

21.3 (s, Ar-CH3’), and 20.1 (s, Ar-CH3) ppm. Anal. Calcd. for C30H33F12NO3W (867.41

g/mol): C: 41.54%; H: 3.83%; N: 1.61%, Found; C: 41.42%; H: 3.73; N: 1.59%.

4.4.6 Synthesis of {CH3Ph3P}{[CF3-ONO]W≡CtBu(OtBu)} (10)

A pentane solution (5 mL) of Ph3PCH2 (0.088 g, 3.19 x10-4 mol) was added drop-

wise to a stirring pentane solution of 10 (0.277 g, 3.19 x10-4 mol) resulting in the

precipitation of a pink powder. The mixture was stirred for 4 h and then the pentane

layer was decanted from the solid. The solid was stirred in fresh pentane for another 2

h. The solid was collect by filtration and dried under vacuum for 1 h (0.228 g, 80%). 1H

NMR (C6D6): δ = 7.76 (s, 1H, Ar-H), 7.61 (s, 1H, Ar-H), 7.47 (d, 1H, Ar-H, 3J = 8.49 Hz),

7.95-7.15 (bs, 16 H, Ar-H), 6.92 (d, 1H, Ar-H, 3J = 8.49 Hz), 6.75 (d, 1H, Ar-H, 3J = 8.49

Hz), 2.36 (d, 3H, CH3PPh3, 2JHP = 13.31 Hz), 2.14 (s, 3H, Ar-CH3), 2.06 (s, 3H, Ar-CH3'),

1.66 (s, 9H, OC(CH3)3), and 1.17 (s, 9H, WCC(CH3)3) ppm. 19F{1H} NMR (C6D6): δ = -

68.67 (q, 3F, -CF3, 4J = 9.61 Hz), -71.19 (q, 3F, -CF3,

4J = 9.61 Hz), -74.39 (q, 3F, -CF3,

4J = 9.61 Hz), and -76.20 (q, 3F, -CF3, 4J = 9.61 Hz) ppm. 31P{1H} NMR (C6D6): δ =

21.59 (s) ppm. 13C{1H} NMR (C6D6): δ = 286.0 (s, WCtBu), 155.5 (s, Ar C), 154.5 (s, Ar

C), 134.6 (s, Ar C), 132.5 (s, Ar C), 131.5 (s, Ar C), 130.3 (s, Ar C), 130.2 (s, Ar C),


(s, Ar C), 122.6 (s, Ar C), 121.0 (s, Ar C), 118.5 (s, Ar C), 77.1 (s, OCMe3), 49.4 (s,

W≡CC(CH3)3), 33.7 (s, W≡CC(CH3)3), 33.5 (s, OC(CH3)3), 20.7 (s, Ar-CH3’), 20.5 (s, Ar-

CH3), and 8.5 (d, H3CPPh3, 1JPC = 57.8 Hz) ppm. Anal. Calcd. for C48H48F12NO3PW

(1129.69 g/mol): C: 51.03%; H: 4.28%; N: 1.24%, Found; C: 50.98%; H: 4.38%; N:

1.18%.

148

4.4.7 Synthesis of {CH3PPh3}{[CF3-ONO]W≡CtBu(OTf)}•0.5 {CH3PPh3}{OTf} (11)

Benzene solutions (2 mL) of 10 (0.201 g, 1.78 x10-4 mol) and MeOTf (0.040 g,

2.44 x10-4 mol) were mixed together and stirred for 0.5 h. The solvent was removed in-

vacuo and the resulting residue dried for 1 h under vacuum. The residue was then

dissolved in minimal benzene and added drop-wise into a cold pentane solution to form

an oily dark-blue precipitate which was collected by filtration (2x). The collected

precipitate was dried under vacuum to yield a dark-blue powder containing 11 and

inseparable {CH3PPh3}{OTf}. Isolated yield was 0.1162 g (approximate yield 50% based

on W). 1H NMR (C6D6): δ = 7.83 (s, 1H, Ar-H), 7.68 (s, 1H, Ar-H), 7.32 (d, 1H, Ar-H, 3J =

8.24 Hz), 7.25-7.00 (bs, ~30 H, Ar-H), 6.97 (d, 1H, Ar-H, 3J = 8.65 Hz), 6.90 (d, 1H, Ar-

H, 3J = 8. 24 Hz), 6.80 (d, 1H, Ar-H, 3J = 8. 65 Hz), 2.29 (d, ~4.75 H, CH3PPh3, 2JHP =

13.31 Hz), 2.10 (s, 3H, Ar-CH3), 2.07 (s, 3H, Ar-CH3'), and 1.07 (s, 9H, WCC(CH3)3)

ppm. 19F{1H} NMR (C6D6): δ = -68.98 (q, 3F, -CF3, 4J = 8.48 Hz), -73.18 (q, 3F, -CF3,

4J

= 8.48 Hz), -73.93 (q, 3F, -CF3, 4J = 9.69 Hz), -76.64 (q, 3F, -CF3,

4J = 9.69 Hz), -76.68

(s, 3F, W-OSO2CF3), and -78.20 (s, 1.29 F, free 0.5 -OTf) ppm. 31P{1H} NMR (C6D6): δ =

21.98 (s) ppm. 13C{1H} NMR (C6D6): δ = 308.6 (s, WCtBu), 152.4 (s, Ar C), 151.4 (s, Ar



(s, Ar C), 118.6 (s, Ar C), 118.0 (s, Ar C), 49.5 (s, W≡CC(CH3)3), 33.7 (s, W≡CC(CH3)3),

20.7 (s, Ar-CH3’), 20.3 (s, Ar-CH3) , and 8.3 (d, H3CPPh3, 1JPC = 57.8 Hz) ppm.

4.4.8 Synthesis of [CF3-ONO]W(≡CtBu)(OEt2) (12)

Complex 11 (0.1162 g) was dissolved in diethyl ether (2 mL). The solution

changes from dark blue to light blue and a white precipitate formed. The white solid was

removed by filtration. Cooling the filtrate precipitates additional white solid, which was

149

subsequently removed via decanting. Slow evaporation of the diethyl ether solution

yielded blue crystals of 12 suitable for single crystal X-ray diffraction concomitant with

inseparable {CH3PPh3}{OTF}. Isolated yield was 0.080 g. In C6D6, the free -OTf

coordinates and displaces diethyl ether. 1H NMR (C6D6): δ = 7.77 (s, 1H, Ar-H), 7.69 (s,

1H, Ar-H), 7.10 (d, 1H, Ar-H, 3J = 8.21 Hz), 7.01 (d, 1H, Ar-H, 3J = 8.21 Hz), 6.74 (s, 2H,

Ar-H), 3.89-3.78 (m, 2H, O(C(H)(H’)CH3)2), 3.71-3.58 (m, 2H, O(C(H)(H’)CH3)2), 2.06 (s,

3H, Ar-CH3), 2.05 (s, 3H, Ar-CH3'), 0.89 (t, 6H, O(CH2CH3)2), and 0.085 (s, 9H,

WCC(CH3)3) ppm. 19F{1H} NMR (C6D6): δ = -69.23 (q, 3F, -CF3, 4J = 8.48 Hz), -71.80 (q,

3F, -CF3, 4J = 9.69 Hz), -75.43 (q, 3F, -CF3,

4J = 9.69 Hz), and -77.19 (q, 3F, -CF3, 4J =

8.48 Hz) ppm. 13C{1H} NMR (C6D6): δ = 311.5 (s, WCtBu), 151.0 (s, Ar C), 150.5 (s, Ar


127.5 (s, Ar C), 126.8 (s, Ar C), 122.3 (s, Ar C), 119.3 (s, Ar C), 79.2 (s, O(CH2CH3)2),

49.9 (s, W≡CC(CH3)3), 33.6 (s, W≡CC(CH3)3), 20.6 (s, Ar-CH3’), 20.2 (s, Ar-CH3) , and

13.4 (s, O(CH2CH3)2) ppm.

4.4.9 Synthesis of [CF3-ONO]W[κ2-C(tBu)C(Me)C(Ph)] (13)

A diethyl ether solution of 10 (0.139 g, 1.23 x10-4 mol), MeOTf (0.020 g, 1.23 x10-

4 mol), and PhC≡CMe (0.014 g, 1.23 x10-4 mol) was allowed to stir overnight. The

solution was filtered and the filtrate reduced. The resulting oily residue was dissolved in

pentane, filtered, and the filtrate was reduced under vacuum. The residue was taken up

in Et2O and slow evaporation yielded crystals of the product. The crystals were rinsed

quickly with pentane and dried (0.058 g, 51%). Crystals suitable for X-ray diffraction

experiments were grown by recrystallizing the material above via a slow evaporation of

a pentane solution. 1H NMR (C6D6): δ = 7.62 (s, 1H, Ar-H), 7.61 (s, 1H, Ar-H), 7.02-7.13

(m, 6H, Ar-H), 6.90 (d, 1H, Ar-H, 3J = 7.55 Hz), 6.87 (d, 1H, Ar-H, 3J = 8.10 Hz), 6.80 (d,

150

1H, Ar-H, 3J = 8.51 Hz), 2.76 (s, 3H, WC3-CH3), 2.00 (s, 3H, Ar-CH3), 1.98 (s, 3H, Ar-

CH3'), 1.18 (s, 9H, WCC(CH3)3) ppm. 19F{1H} NMR (C6D6): δ = -71.49 (q, 3F, -CF3, 4J =

9.69 Hz), -72.07 (q, 3F, -CF3, 4J = 9.69 Hz), -76.06 (q, 3F, -CF3,

4J = 9.69 Hz), and -

76.53 (q, 3F, -CF3, 4J = 9.69 Hz) ppm. 13C{1H} NMR (C6D6): δ = 244.6 (s, WCα), 242.3

(s, WCα), 146.0 (s, Ar C), 144.9 (s, Ar C), 138.2 (s, WC2Cβ), 138.2 (s, Ar C), 132.4 (s, Ar



(s, Ar C), 42.3 (s, WC3-C(CH3)3), 30.2 (s, WC3-C(CH3)3), 20.4 (s, Ar-CH3), 20.3 (s, Ar-

CH3'), and 15.8 (s, WC3-CH3) ppm. Anal. Calcd. for C35H31F12NO2W (909.45 g/mol): C:

46.22%; H: 3.44%; N: 1.54%, Found; C: 46.31%; H: 3.50%; N: 1.60%.

4.4.10 Synthesis of [CF3-ONO]W[κ2-C(tBu)C(Me)C(tBu)] (14)

A C6D6 solution of 4,4-dimethyl-2-pentyne (0.018 g, 1.9 x10-4 mol) and complex

12, that was generated in-situ from 10 (0.183 g, 1.62 x10-4 mol) and MeOTf (0.027 g,

1.7 x10-4 mol), was heated in a J-young tube at 60° C for 3 h. The solvent was removed

in-vacuo. The solid residue was dissolved in Et2O (1 mL) and precipitated by the

addition of hexanes to yield a purple powder. The solid was removed by filtration and

the filtrate was reduced to give a brown powder. The powder was quickly rinsed with

pentanes, and then dissolved in Et2O. Slow evaporation of the ether solution yielded

brown crystals of 14 (0.068 g, 47 %). 1H NMR (C6D6): δ = 7.62 (s, 2H, Ar-H), 7.06 (d,

2H, Ar-H, 3J = 8.37 Hz), 6.84 (d, 2H, Ar-H, 3J = 8.37 Hz), 2.97 (s, 3H, WC3-CH3), 2.00

(s, 6H, Ar-CH3), and 1.19 (s, 18 H, WC3-C(CH3)3) ppm. 19F{1H} NMR (C6D6): δ = -71.87

(q, 3F, -CF3, 4J = 9.69 Hz) and -76.53 (q, 3F, -CF3,

4J = 9.69 Hz) ppm. 13C{1H} NMR

(C6D6): δ = 252.8 (s, WCα), 146.4 (s, Ar C), 139.0 (s, WC2Cβ), 132.9 (s, Ar C), 132.6 (s,

Ar C), 128.9 (s, Ar C), 127.3 (s, Ar C), 125.6 (s, Ar C), 43.3 (s, WC3-C(CH3)3), 30.9 (s,

151

WC3-C(CH3)3), 21.1 (s, Ar-CH3), and 12.3 (s, WC3-CH3) ppm. Anal. Calcd. for

C33H35F12NO2W (909.45 g/mol): C: 44.56%; H: 3.97%; N: 1.57%, Found; C: 44.45%; H:

4.08%; N: 1.57%.

4.4.11 Synthesis of [CF3-ONO]W[κ2-C(tBu)C(CH2(CH2)4CH2)C] (15)

A diethyl ether solution of cyclooctyne (0.040 g, 3.7 x10-4 mol) was added to an

Et2O solution containing complex 12 that was generated in-situ from 10 (0.213 g, 1.89

x10-4 mol) and MeOTf (0.070 g, 4.27 x10-4 mol). The solution was stirred for 0.5 h and

the solution changed color from blue to red-brown. The solution was filtered and

reduced to provide an oily solid. The residue was dissolved in pentanes and filtered.

Slow evaporation of the pentane filtrate yielded crystals of 15. The solution was

decanted from the crystals and the collected material was recrystallized a second time

from a slow evaporating diethyl ether solution (0.065 g, 38%). 1H NMR (C6D6): δ = 7.69

(s, Ar-H), 7.61 (s, Ar-H), 7.12 (d, 1H, Ar-H, 3J = 7.82 Hz), 7.10 (d, 1H, Ar-H, 3J = 7.69

Hz), 6.88 (d, 1H, Ar-H, 3J = 8.37 Hz), 6.85 (d, 1H, Ar-H, 3J = 8.51 Hz), 3.82 (dt, 1H,

WC3-C(H)(H')-R, 2J = 11.67 Hz, 3J = 4.80 Hz), 3.66 (m, 1H, WC3-[C(H)(H')(CH2)4CH2]),

3.36 (m, 1H, WC3-[CH2(CH2)4C(H)(H')]), 3.18 (m, 1H, WC3-C(H)(H')-R), 2.05 (s, 3H, Ar-

CH3), 2.01 (s, 3H, Ar-CH3'), 1.18 (s, 9H, WC3-C(CH3)3), and 0.90-1.55 (bs, 8H, WC3-

[CH2(CH2)4CH2]) ppm. 19F{1H} NMR (C6D6): δ = -70.92 (q, 3F, -CF3, 4J = 9.69 Hz), -

72.22 (q, 3F, -CF3, 4J = 9.69 Hz), -76.06 (q, 3F, -CF3,

4J = 9.69 Hz), and -76.56 (q, 3F, -

CF3, 4J = 9.69 Hz) ppm. 13C{1H} = 252.8 (s, WCα), 238.6 (s, WCα), 145.1 (s, Ar C), 144.6

(s, Ar C), 142.8 (s, WC2Cβ), 132.4 (s, Ar C), 132.0 (s, Ar C), 131.9 (s, Ar C), 131.4 (s, Ar


124.2 (s, Ar C), 42.0 (s, WC3-C(CH3)3), 35.5 (s, WC3-[CH2(CH2)4CH2]), 31.0 (s, WC3-

C(CH3)3), 31.0 (s, WC3-[CH2(CH2)4CH2]), 29.5 (s, WC3-[CH2(CH2)4CH2]), 26.9 (s, WC3-

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[CH2(CH2)4CH2]), 26.0 (s, WC3-[CH2(CH2)4CH2]), 24.0 (s, WC3-[CH2(CH2)4CH2]), 20.4

(s, Ar-CH3), and 20.3 (s, Ar-CH3') ppm. Anal. Calcd. for C34H35F12NO2W (901.47 g/mol):

C: 45.30%; H: 3.91%; N: 1.55%, Found; C: 45.31%; H: 3.97%; N: 1.56%.

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Figure 4- 1. Ancillary ligand rearrangement during alkyne metathesis.

Figure 4- 2. Delicate balance of lowering activation energy while keeping the alkylidyne and metallacyclobutadiene thermoneutral.

Figure 4- 3. The push-pull electronic effect of the [CF3-ONO] pincer-type ligand and the inorganic enamine bonding structure.

154

Figure 4- 4. Initial proposed synthesis of an [CF3-ONO] ligand.




155

Figure 4- 8. Synthesis of 11 and 12.

Figure 4- 9. Molecular structure of [CF3-ONO]W(≡CtBu)(OEt2) (12) with ellipsoids drawn at 50% Probability level, with hydrogens removed for clarity. Only one of two disordered conformations at C28 is shown for clarity.

156

Figure 4- 10. Synthesis of tungstenacyclobutadienes 13, 14, and 15.

157

Figure 4- 11. Molecular structure of [CF3-ONO]W[κ2-C(tBu)C(Me)C(Ph)] (19) with ellipsoids drawn at 50% probability level, with hydrogens removed for clarity.

Figure 4- 12. Reported X-ray crystallographic bond length and angles of W(κ2-C3Et3)(ImN){OCMe(CF3)2}2 (A),305 W[κ2-C(tBu)C(Me)C(Me)]Cl3 (B),323 W(κ2-C3Et3)[O-2,6-C6H3(

iPr)2]3 (C),301 W(κ2-C3Et3)[OCH(CF3)2]3 (D),302 19, 20, and 21.

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Table 4- 1. Selected metric parameters for the WC3 rings of 19, 20, and 21.

Bond length(Å) 19 20 21

W1-C21 1.9046(16) 1.882(3) 1.911(3)

W1-C23 1.9106(18) 1.908(3) 1.897(3)

C21-C22 1.450(3) 1.456(4) 1.443(4)

C22-C23 1.473(2) 1.453(4) 1.473(4)

W1-N1 2.0158(14) 2.022(2) 2.023(2)

Table 4- 2. Selected metric parameters for the WC3 rings of 19, 20, and 21.

Bond angle(°) 19 20 21

N1-W1-C21 122.99(7) 122.65(10) 123.66(10)

N1-W1-C23 153.60(6) 154.02(10) 153.22(10)

O1-W1-O2 147.78(5) 147.39(8) 147.80(7)

Figure 4- 13. Fluxional WC3 ring conformations.

W N W

R 3

R 2

R 1

O

O

W N W

R 1 R 2

R 3 O

O

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Figure 4- 14. Molecular structure of [CF3-ONO]W[C(tBu)C(Me)C(tBu)] (14) with ellipsoids drawn at 50% probability level, with hydrogens removed for clarity. A disordered W ion position (7%) is removed for clarity.

Figure 4- 15. Molecular structure of [CF3-ONO]W[C(tBu)C(CH2)6C] (15) with ellipsoids drawn at 50% probability level, with hydrogens removed for clarity. Only one of two disordered conformation at C30 and C31 are shown for clarity.

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Figure 4- 16. DFT geometry optimized structures of 12 and 13 with calculated bond lengths (red) and crystallographic determined lengths (black).

161

Figure 4- 17. Truncated MO diagram of 12 and 13. (isovalues = 0.051687).

162

Table 4- 3. 15N NMR chemical shifts of 9-15.

9 10 11 12 13 14 15

ppm 225.7 149.3 165.5 178.3 208.6 204.4 202.1

Figure 4- 18. Amido lone pair orientation for varying ligand systems of tungsten alkylidyne and tungstenacyclobutadiene complexes (I, II,304, 305 and III304).

163

Figure 4- 19. Reaction progress vs free energy diagram for retro-[2+2]-cycloaddition.

Figure 4- 20. Nitrile-alkyne cross metathesis upon treating 18 with MeCN.

164

CHAPTER 5 AN ONO3- TRIANIONIC PINCER-TYPE LIGAND FOR GENERATING HIGHLY

NUCLEOPHILIC METAL-CARBON MULTIPLE BONDS: AN INORGANIC ENAMINE

5.1 Introduction

In Chapter 4, we introduced the trianionic ONO pincer-type ligand supported

tungsten alkylidyne. Unfortunately, the complex when treated with an alkyne stops at

the cycloaddition intermediate and fails to catalyze alkyne metathesis. Contributing to

the large thermodynamic gradient preventing a needed reversible cycloaddtion is the

loss of the reactive inorganic enamine interaction between the amido lone pair and the

alkylidyne π bond upon cycloaddition. Still, the [CF3-ONO] ligand may serve other

useful purposes. In one aspect, the inorganic enamine interaction offers the potential to

increase the nucleophilicity of metal ligand multiple bonds, which can be utilized for the

purposes of C−H bond activation. Here we discuss more fully the concept of an

inorganic enamine and provide examples that demonstrate this reactivity.

Metal-ligand multiple bonds featuring groups 4 and 5 transition metals (especially

the first row derivatives) have a significant ionic component.343-347 A simple explanation

for this phenonmena is that early transition metals are considerably electropositive,

while a more descriptive explanation would take into account the mismatched atomic

orbital energies of the metal d-orbitals relative to the low-lying ligand counterpart.

As a result of the significantly polarized bonding, the electron density

accumulates on the alkylidyne ligand. The additional electron density is well-received by

electronegative atoms as oxygen, but less so by carbon which becomes highly

nucleophilic.343, 344, 347-349 Superlative examples of the nucleophilic reactivity include the

Adapted with permission from M. E. O'Reilly, I. Ghiviriga, K. A. Abboud and A. S. Veige, J. Am. Chem.

Soc., 2012, 134, 11185-11195. Copyright 2012 American Chemical Society.

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alkyl-aluminum stabilized Tebbe’s reagents (Cp2Ti(µ-CH2)(µ-X)Al(CH3)2 (X = Cl, Me)350-

353 and recently Mindiola’s titanium ([PNP]Ti≡CtBu)280, 354-362 and vanadium

([nacnac]V≡CtBu) alkylidynes.363, 364 Recently, Mindiola and coworkers have harnessed

the nucleophilicity of a titanium alkylidyne to activate the inert C−H bond of methane.354

A drastic change in the nucleophilicity of the M−C multiple bond occurs upon

moving from group 4 to group 6 metal complexes. Group 6 metal-carbon multiple

bonds276 of molybdenum(VI) and tungsten(VI) are more covalent and correspondingly

less nucleophilic.343, 345-347 As a result, these complexes are well suited for alkene and

alkyne metathesis.

A challenge from an organometallic perspective is to develop methodologies that

fine tune the nucleophilicity of the M−C multiple bonds, with minimal disturbance to the

selected metal center. The appropriate ancillary ligand design provides the possibility of

controlling the electronic structure of M−C multiple bonds to create highly nucleophilic

species. Methodologies that accentuate the nucleophilicity of metal-ligand multiple

bonds are useful for 1,2-C−H activation and other inert bond activations. Herein, we

present a rational approach to creating tungsten-carbon multiple bonds with high

nucleophilicity at the α-carbon by employing a push-pull strategy that employs an

inorganic enamine bonding concept for the push.

To create a highly nucleophilic polarized metal-carbon bond, the ancillary ligand

must polarize the M−C multiple bond. In other words, the ligand must induce an

electrophilic metal center while pushing electron density to the α-carbon, a so- called

push-pull effect.365 However, simply inducing an electronically-starved metal serves to

diminish the nucleophilicity at the α-carbon by forming a more covalent M-C multiple

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bond. The challenges in polarizing the M-C multiple bond lies in accumulating electron

density on the α-carbon while removing it from the metal center.

Some of the most highly active alkene366, 367 and alkyne279, 295, 303-306 metathesis

catalysts employ a push-pull idea by pairing an electron-rich imido or amido ligand

coupled with weakly π-donating fluorinated alkoxides (-OC(CF3)2CH3). The fluorinated

alkoxides are poorly basic and create an electrophilic metal, but the role of the imido or

amido is not as clear.304, 368 For monodentate amido ligands, the lone pair on the

nitrogen preferably orients perpendicular to the metal-carbon multiple bond and donates

into a low-lying vacant dxy orbital, which operates against the goal to create an

electrophilic metal ion (Figure 5-1).303-305, 369-371 To avoid this, the [CF3-ONO] ligand

purposely orients the amido lone pair collinear or closely aligned with the metal-carbon

bond axis (Figure 5-1). The resulting bonding interaction is what we term an inorganic

enamine.

Appending an amine to an olefin yields a so-called enamine. The reactivity of

enamines was originally developed by Stork and coworkers in Stork-enamine alkylation

reactions,372-374 which more recently has been expanded beyond stoichiometric

reactions to organocatalysis.375-379 Within the enamine bonding structure, the nitrogen

lone pair serves to generate a nucleophilic α-carbon. A simple resonance structure

depiction helps to explain the observed increased nucleophilicity (Figure 5-2).373, 374 The

nitrogen lone pair “pushes” electron density through resonance structure to the carbon

atom two bonds away. In principle, replacing the alkene with a metal alkylidene (M=C)

should yield a similar bonding interaction that increases the nucleophilicity of the

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alkylidene α-carbon. Hence, employing the enamine bonding concept to metal-ligand

multiple bonds may lead to exciting new reactivity.

A better understanding of the electronic structure within an enamine and/or

inorganic enamine requires a molecular orbital diagram. In both examples, the N-atom

lone pair forms a bonding and antibonding combination with the C=C π-bond, or in the

case of alkylidenes, the M=C π-bond (Figure 5-3). The energetic consequence is two-

fold. The π-bonding electrons in the HOMO(-1) are stabilized by additional overlap with

the N orbital, while the nitrogen lone pair (HOMO) forms a destabilizing anti-bonding

interaction with the π-bond. A second important feature is the size of each atomic orbital

contribution in the HOMO. As noted earlier, the nitrogen lone pair pushes electron

density two-bonds away. This property is evident in the HOMO; the appended carbon

atom or the metal center has low contributions to the molecular orbital, while the α-

carbon is exceptionally larger. This effect increases electron density on the α-carbon,

while concurrently retaining an electron deficient metal ion.

As mentioned earlier, the challenge for synthesizing an inorganic enamine is that

the unrestricted amido ligand will orient the lone pair perpendicular to the M-C bond

(Figure 5-1). Multidentate ligands offer the possibility to constrain the amido lone pair

orientation. Trianionic NCN27-30 and OCO31-42 pincer ligands are excellent examples of a

rigid meridional environment and have been utilized for catalytic aerobic oxidation,36

alkene isomerization28 and polymerization,27, 42 alkyne polymerization,31 and

fundamental transformations34 involving oxygen-atom transfer,32 nitrogen-atom

transfer,38 and dioxygen activation.33 In addition, Heyduk et al. introduced redox active

trianionic ONO3-, NNN3-, and SNS3- pincer-type ligands.45-52, 55, 58 Figure 5-4 depicts a

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CF3-ONO3- pincer-type ligand that incorporates all the essential design features needed

to create a highly nucleophilic metal-carbon multiple bond. The fluorinated alkoxides

induce an electrophilic metal centre (pull); the constrained pincer framework prevents

amido π-donation into the dxy orbital, and instead the lone pair interacts with the metal-

carbon π-bond (push).

Accomplishing this objective, we now present a rationally designed trianionic

pincer-type ligand that increases the nucleophilicity of a tungsten alkylidene [CF3-

ONO]W=C(Et)(OtBu) (16) and a alkylidyne {MePPh3}{[CF3-ONO]W≡C(Et)(OtBu)} (17).

Demonstrating high nucleophilicity, addition of a Me3SiOTf to 16 and 17 expels

isobutylene in an intramolecular C-H bond activation pathway.

5.2 Results

5.2.2 Synthesis and Characterization of [CF3-ONO]W=CH(Et)(OtBu) (16)

In benzene, combining proligand 8 with (tBuO)3W≡C(Et)286 results in the

immediate formation of the trianionic pincer alkylidene complex [CF3-

ONO]W=CH(Et)(OtBu) (16) according to Figure 5-6. Isolation of reasonably pure 16 only

requires removal of all volatiles in vacuo; recrystallizing 16 in pentane provides

analytically pure material. Single crystals amenable to an X-ray diffraction experiment

deposit upon cooling a concentrated pentane solution of 16 to -35 °C. Structure

refinement of the diffraction data provides the molecular structure of 16 presented in

Figure 5-7.

Complex 16 is C1-symmetric, and occupying the basal plane of the distorted

square-pyramidal tungsten(VI) geometry are the ONO3- trianionic pincer ligand and tert-

butoxide. In the apical position resides a propylidene ligand with a W–Cα bond length of

1.882(4) Å, which is consistent with a double bond and similar to two other OCO3-

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trianionic pincer W-alkylidenes that have bond lengths of 1.887 and 1.913 Å.35

Consistent with a W=C double bond, the 13C{1H} NMR spectrum of 16 contains a

downfield resonance at 260.3 ppm (1J(13C, 183W) = 173.1 Hz) and the corresponding

alkylidene proton (W=CHR) resonates as a triplet at 7.36 ppm. An interesting structural

feature appears in the trianionic pincer ligand framework. Unable to lie coplanar, the N-

aryl rings twist, thereby lowering the solid state symmetry from potentially Cs to C1. This

twist and resulting low symmetry persists in solution as four distinct quartets appear in

the 19F NMR spectrum of 16 at -71.2, -71.5, -73.9, and -77.2 ppm. The low symmetry

also results in diastereotopic –CβH2– methylene protons for the propylidene ligand that

appear as two multiplets at 5.08 ppm and 4.79 ppm. The propylidene methyl appears as

a triplet at 0.77 ppm (3J = 7.36 Hz). The nitrogen atom of the ONO ligand is trigonal

planar (sum of angles = 359.6(4)), consistent with sp2 hybridization.

The alkylidene bond orients as the anti-isomer and does not rotate with an

appreciable rate even at 100 °C. No signals attributable to an exchange with the syn-

isomer appear in variable temperature 1H NMR spectra of 16 from –60 °C to 100 °C. In

Schrock’s tungsten imido alkylidene, the syn-isomer predominantly forms (Ksyn/anti =

5000), but access to the anti-isomer is possible by exposing a sample to UV-radiation at

-85 °C for several hours.380 The relaxation of the anti-isomer back to syn occurs

between -53 °C to -38 °C.380 Interestingly, the rate of relaxation decreases as the

alkoxide ligands become more fluorinated.381 Invoking similar conditions for complex 9,

a toluene-d8 solution of 9 exposed to 366 nm light for 4 h at -78 °C does not yield any

detectable syn-isomer as determined by 1H NMR (500 MHz) spectroscopy.

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5.2.3 Synthesis and Characterization of {[CF3-ONO]W≡C(Et)(OtBu)}{MePPh3} (17)

Deprotonating alkylidenes with methylenetriphenylphosphorane (Ph3P=CH2) is a

convenient method to access the corresponding alkylidyne anion.339 Treating alkylidene

16 with Ph3P=CH2 in pentane at 25 °C precipitates the W-alkylidyne anion 17 (Figure 5-

8). Complex 17 turns to a bright red color upon dissolving in benzene or ether.

Removing the solvent by vacuum yields a red oil, but the addition of cold pentane

returns 17 to a yellow powder.

Multinuclear 1H-13C gHSQC and 1H-13C gHMBC NMR spectroscopic experiments

confirm the identity of 17 and permit the absolute assignment of all resonances in the 1H

and 13C{1H} NMR spectra (Appendix). Most pronounced is the downfield shift to 280.6

ppm for the W≡Cα alkylidyne carbon in the 13C{1H} NMR spectrum. In the 1H NMR

spectrum, a doublet (JHP = 13.31 Hz) at 2.44 ppm is attributable to the methyl protons of

the phosphonium counter cation, and the corresponding phosphorus resonates at 21.8

ppm in the 31P{1H} NMR spectrum. Consistent again with a C1-symmetric complex, the

19F NMR spectrum contains four distinct quartets at -69.38, -71.24, -74.08, and -76.38

ppm.

5.2.4 Reactivity Studies, Nucleophilic at Carbon

Adding methyl triflate to 17 in a sealable NMR tube results in alkylation of the

alkylidyne carbon to form [CF3-ONO]W=C(Me)(Et)(OtBu) (18) (Figure 5-9). Confirming

the identity of 18, a 1H NMR spectrum of the reaction mixture reveals a resonance

attributable to the newly formed methyl protons (W=C(CH3)Et) at 4.90 ppm (3H). The –

CβH2– methylene protons are diastereotopic, resonating as two sets of multiplets at 4.65

and 4.53 ppm, similar to complex 16. The -OtBu protons resonate at 1.21 ppm (9H). The

W-Cα resonates at 284.3 ppm, consistent with other reported tungsten dialkyl-

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substituted alkylidenes.382-384 The 1H-13C gHMBC spectrum of 18 confirms the

connectivity among the methyl protons at 4.90 ppm, the diastereotopic methylene

protons at 4.65 and 4.53 ppm, and the alkylidene carbon. Unidentifiable and

inseparable minor impurities precluded the large-scale purification of 18.

5.2.5 Isobutylene Expulsion from 17

Adding the larger electrophile Me3SiOTf to complex 17 in a sealable NMR tube

provides an interesting result. The products observed by 1H NMR spectroscopy are

isobutylene (4.71 ppm, 2H; and 1.56 ppm, 6 H) and the new alkylidene complex [CF3-

ONO]W=CH(Et)OSiMe3 (19) (Figure 5-10). Complex 19 exhibits a new set of

diastereotopic –CβH2– methylene protons at 5.28 and 4.91 ppm, and the

trimethylsiloxide protons appear at 0.12 ppm. Corroborating the identity of 19, the

W=CH proton resonates at 7.20 ppm and the corresponding 13C{1H} signal appears at

262.1 ppm. Multinuclear 1H-13C gHSQC and 1H-13C gHMBC NMR spectroscopic

experiments confirm the identity of 19 and permit the absolute assignment of all

resonances in the 1H and 13C{1H} NMR spectra (Appendix). Complex 19 is unstable at

ambient temperature and decomposes to unidentifiable and intractable impurities.

5.2.6 Catalytic Isobutylene Expulsion from 16

As mentioned above, complex 16 contains a restricted amide rotation similar to

that of complex 3. The amide lone pair and alkylidene of 16 form a torsion angle of

44.34°. Considering the reactivity of complex 17, would complex 16 undergo a similar

reactivity in the presence of Me3SiOTf?

Treating complex 16 with Me3SiOTf also results in isobutylene expulsion as well

as the formation of [CF3-ONO]W(O)nPr (20). The absence of Me3SiOTf in the product

suggests a catalytic role in the expulsion of isobutylene from 16. Indeed, adding 5 mol

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% Me3SiOTf, MeOTf, or B(C6F5)3 to a solution of 16 catalyzes isobutylene expulsion to

form 20 quantitatively by 1H NMR spectroscopy (Figure 5-11). Stripping the solvent from

20 initially yields a thick blue oil, but crystals suitable for single crystal X-ray analysis

gradually form (isolated yield = 73%). The solid state structure of 20 (Figure 5-12)

contains a tungsten(VI) ion in a trigonal bipyramidal geometry with equatorial plane

angles N1-W1-O3 = 129.69°, N1-W1-C21 = 121.46°, and C21-W1-O3 = 108.82(10) °.

The W1-O3 bond is 1.704 Å, which is consistent with other reported neutral WVI=O

complexes.119, 384-402 The 19F NMR of 20 confirms a C1 symmetric species in solution

with four quartets at -71.17, -71.77, -75.55, and -76.38 ppm. The α-protons of the propyl

group {WCH2CH2CH3) resonate in the 1H NMR as a multiplet at 3.00 ppm. The β-

protons and γ-protons of the propyl group appear as a multiplet at 2.65 ppm and a triplet

at 0.92 ppm, respectively. The nitrogen atom is sp2 hybridized and a vector

perpendicular to the amido plane, representing the lone pair on nitrogen, forms a 39.72°

torsion angle with the W=O bond.

5.2.7 Computational Results

Employing DFT calculations, the model complexes 16', 16-Me', and 17',

representing 16, the intermediate 16-Me, and 17, respectively, were geometry

optimized. Figure 5-13 depicts the computed structures and Table 5-1 and Table 5-2 list

pertinent bond lengths and angles. Experimental bond lengths and angles for 16 serve

to calibrate the calculated structure of 16'. The tungsten coordination sphere metric

parameters are agreeable and it is clear the calculation reproduces the twist of the ONO

backbone observed experimentally. A vector perpendicular to the C3-W1-C13 plane,

representing the nitrogen lone pair, creates a 41.7° dihedral angle with the W1-C1 bond

axis (the experimental value is 40.5°). Also, the alkylidene orients in the same direction

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as in 9. The alkylidene ethyl group points away from the N-atom. A quantifiable

parameter confirming the similar orientation is the dihedral angle C22-C21-W1-O3; for

16 it is 10.2° and within 9' it is 11.7°. In general there is a small over- estimate of most

of the bond lengths by 0.02 Å or less. For example the N1-W1 distance of 2.013 Å in 16'

is slightly longer than in 16 (1.993(3)); and the computed alkylidene W1-C21 bond

length of 1.898 matches the experimental value of 1.882(4).

The computed structures of 16-Me' and 17' also reproduce the ONO twist and

some interesting trends emerge between the set of three complexes. Most apparent is

the W-N bond distance, that increases with 16-Me' (1.982) < 16' (2.013) < 17' (2.142).

The computation accurately predicts a trend assignable to an increase in electronic

saturation at the metal ion. Complex 17' is anionic, thus electron-rich, whereas 16-Me'

is electron-poor, due to the loss of π-donation upon methylating the alkoxide O-atom.

Correspondingly, the W-O bond length of 2.136 Å for the bound tert-butylmethyl ether in

16-Me' is appropriately longer than the tert-butoxide of 17', and only slight shorter by ~

0.05 Å than the crystallographically characterized diethyl ether W-O bond of 2.185(2) Å

found in the related OCO3- pincer alkylidyne [tBuOCO]W≡C(tBu)(Et2O).31

The most salient feature of complex 17' is the alkylidyne W≡C bond with a length

of 1.769 Å that matches experimentally determined values. Though there are no

structurally characterized trianionic pincer alkylidyne anions known, two neutral OCO3-

pincer complexes have W≡C bond lengths of 1.755(2) and 1.759(4) Å. For additional

comparison, Schrock’s (ArO)2NpW≡C(tBu)403 complex contains a W≡C bond length of

1.755(2) Å, a difference of only ~0.01 Å with 10'. Considering the reasonable match in

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metric parameters, single point calculations of each complex were performed and the

resulting electronic structures were evaluated, vide infra.

5.3 Discussion

5.3.1 An Enhanced Nucleophilic Reactivity from 17

MeOTf alkylation at the Cα atom of the alkylidyne in 17 has a different reactivity

pattern compared to previous examples. Alkylating agents preferentially attack the

ancillary ligands leaving both neutral and anionic tungsten alkylidynes intact.319 Similarly

for anionic molybdenum imido alkylidyne complexes, both small ([Me3O][BF4]) and large

(Me3SiOTf) electrophiles selectively attack the imido N-atom.339 The direct alkylation of

the W≡Cα bond by MeOTf has no precedent in the literature. Enamines react with

electrophiles at the β-position, whereas unfuctionalized alkenes do not. Electronically,

complex 17 is analogous to an enamine. Examining the electronic structure of 17

through single point calculations provides insight into how the CF3-ONO pincer ligand

influences the tungsten alkylidyne bond.

5.3.2 Single Point DFT Calculations of 17

Figure 5-14 depicts a truncated molecular orbital diagram that illustrates the

bonding combination between the amido lone pair and the W≡C π-bond. The key

feature is the forced torsion angle between the alkylidyne bond and the amide lone pair.

This contrasts the typical arrangement in which the nitrogen lone pair orients

perpendicularly to the alkylidyne bond to maximize π-donation into the empty dxy. The

rigid ONO pincer geometry within 17 prevents the amide from orienting perpendicularly

to the alkylidyne and instead the LUMO of 17', consisting of the dxy orbital, contains no

orbital interaction with the amido lone pair (Figure 5-14).

175

The alkylidyne π-bond facing the nitrogen (HOMO(-2)) displays overlap with the

nitrogen’s lone pair, lowering its energy relative to the adjacent π-bond (HOMO(-1)) by

0.01139 AU (Figure 5-14). A torsion angle of 42.8° between the lone pair and the

alkylidyne bond results in significant overlap. The corresponding anti-bonding

combination corresponds to the HOMO orbital analogous to an enamine (Figure 5-3).

This bonding-antibonding interaction raises the energy of the HOMO, thus increasing

the nucleophilicity of the alkylidyne α-carbon.

In stark contrast is the single point calculation from a geometry optimized

structure performed on the model anionic alkylidyne

{(Ph2N)W≡C(Me)(OC(CF3)2Ph)2(OtBu)}- (21'). The amido ligand orientation matches the

analogous complex {3,5-C6H3Me2)tBuN}W≡C(tBu){OC(CF3)3}2 calculated by Tamm and

co-workers.304 Depicted in Figure 5-15 are the single point calculations of 17' and 21',

aligned for easy comparison. The model complex 21' features an unrestricted amido

ligand N(C6H5)2, yet retains the electron-withdrawing OC(CF3)2C6H5 groups. In 21' the

amido ligand orients to maximize π-donation into the empty dxy orbital, which serves to

stabilize the HOMO orbital comprised mostly of the N-atom lone pair. However, the M-C

π-bonding orbitals are completely unaffected by the N-atom lone pair. By comparing the

electronic structures, it is evident that purposely constraining the N-atom lone pair to be

collinear with the M≡C bond destabilizes the HOMO orbital and places increased

electron density on the α-carbon.


Isobutylene expulsion provides more evidence for the nucleophilicity of 17.

Figure 5-16 illustrates a proposed mechanism for isobutylene expulsion. In the first step,

Me3SiOTf attacks the tert-butoxide ligand to yield the trimethylsilyl-tert-butyl ether

176

adduct, 17-SiMe3. Then, acting as a nucleophile, the W-alkylidyne deprotonates the

tert-butyl group to expel isobutylene and form 19. tert-Butoxide is a common ligand,

especially for tungsten complexes featuring M-C multiple bonds, but this is the first

occurrence of its degradation via alkylidyne deprotonation and is clear evidence of the

highly nucleophilic character of the W-Cα atom.

Additional evidence that the N-atom plays an important role comes from reactivity

studies employing the related OCO3- pincer ligand. Without the N-atom a different

reaction occurs; addition of MeOTf to the analogous OCO trianionic pincer alkylidyne

anion {MePPh3}{[tBuOCO]W≡C(tBu)(OtBu)} produces [tBuOCO]W≡C(tBu)(OEt2).

31 The

reaction proceeds via Me-alkylation of the tert-butoxide but deprotonation does not

occur; instead, MeOtBu forms. Notably, the Me+ adds to the alkoxide and not the

alkylidyne α-carbon as in 17.

Not all of the divergent chemistry between the CF3-ONO3- and the OCO3- ligands

are attributable to the N-atom alone. An additional significant difference is the

fluorinated alkoxides on CF3-ONO3-, which create an electrophilic tungsten ion.

Silylating the -OtBu of 17 removes π-donation from the alkoxide and leaves only a

weakly σ-donating ether. The result is an even more electrophilic tungsten metal. Yet,

other electrophilic tungsten alkylidynes supported by three -OC(CF3)Me are known

metathesis catalysts that show stability towards substrates containing ether, ester,

ketone, aldehyde, acetal, and thioether moieties,281 and are only protonated via

hydrohalic acids.367, 404 The combination of the N-atom and the electron-withdrawing

CF3 groups must lead to deprotonation of the tert-butoxide.

177


The Lewis acid-catalyzed expulsion of isobutylene from 16 demonstrates W-C

double bonds with the CF3-ONO3- ligands are also highly nucleophilic. Figure 5-17

depicts the proposed mechanism for the Lewis acid-catalyzed isobutylene expulsion

from 9. Two plausible sites for electrophilic (LA) attack on 16 are the amido N-atom and

the tert-butoxide O-atom. The N-atom is too sterically crowded, especially for large

electrophiles such as B(C6F5)3 and Me3SiOTf, which catalyze the reaction too. Thus,

initial attack must occur at the tert-butoxide to form 16-LA. Proceeding from 16-LA, the

alkylidene deprotonates the tBu group to form isobutylene and 20-LA. The Lewis acid

catalyst is then released to provide 20.

An interesting question arises regarding the deprotonation event. Structural

characterization and subsequent variable-temperature NMR experiments indicate the

alkylidene W=C bond in 16 is perpendicular to the tert-butoxide ligand (Figure 5-18). To

complete the deprotonation the π-bond needs to approach the proton of the tert-

butoxide. Curious as to the orientation of the alkylidene in 16-LA, we performed a

geometry optimization calculation of 16-Me', in which Me+ serves as the Lewis acid

(Figure 5-13). The electrophile accepts a pair of electrons from the oxygen atom that

normally π-donate into the W-dxy orbital. Most pronounced and interestingly, the

alkylidene in 16-Me' rotates ~77° from that of the experimentally determined structure of

16. Illustrated in Figure 5-18 is a truncated X-ray structure of 16 and the computed

structure 16-Me'. The double bond clearly orients towards the MeOtBu. A single point

calculation of 16-Me' again reveals the HOMO and HOMO(-5) are the amide/alkylidene

π-antibonding and –bonding (Figure 5-19), respectively, analogous to that calculated for

178

17 and a prototypical enamine. The LUMO of 16-Me' (not depicted) consists of the dxy

orbital and contains only a small component from N-atom lone pair and ether ligand.

5.4 Conclusion

Traditionally, tungsten alkylidenes/alkylidynes are weakly nucleophilic, and are

ideally suited for alkene and alkyne metathesis. Presented above is a rationally

designed ONO pincer-type ligand that enhances the nucleophilicity of W-C multiple

bonds for C−H activation. The [CF3-ONO] ligand effectively polarizes W-C multiple

bonds through a unique push-pull combination. The fluorinated alkoxides induce an

electron deficient tungsten ion (pull), while the alignment of the amido lone pair with the

W-C multiple bond pushes electron density on the α-carbon through a unique inorganic

enamine interaction. More importantly, the inorganic enamine presents a new strategy

to accentuate the nucleophilicity of alkylidene and alkylidyne complexes. Evidence for

the enhanced reactivity arising from an inorganic enamine is the direct alkylation of the

alkylidyne in 10 with MeOTf; and isobutylene expulsion upon addition of the larger

Me3SiOTf. Complementing these results is the Lewis acid-catalyzed expulsion of

isobutylene from 9.

Trianionic pincer and pincer-type ligands are suitable frameworks to explore the

reactivity from a constrained amide orientation. Here we provide a new approach to

increase the nucleophilicity of M-C multiple bonds, that may be employed with other

metal-ligand multiple bonds. Future work in this area explores how the constrained

amide orientation within a metal coordination sphere may induce/alter new types of

reactivity.

179

5.5 Experimental




toluene, diethyl ether (Et2O), dichloromethane, tetrahydrofuran (THF), and 1,2-

dimethoxyethane (DME) were dried using a GlassContour drying column. Benzene-d6

(Cambridge Isotopes) was dried over sodium-benzophenone ketyl, distilled or vacuum

transferred, and stored over 4 Å molecular sieves. Bis(2-bromo-4-

methylphenyl)amine,307 PPh3CH2,339 and (tBuO)3W≡C(Et)286 were prepared according

to published literature procedures. All other reagents were purchased from commercial

vendors and used without further purification.








IR Techniques: Infrared spectra were obtained on a Thermo Scientific Nicolet

6700 FT-IR.

5.5.3 Calculations

Spin-restricted density functional theory calculations, including geometry

optimization and single point analysis were performed for 16', 16-Me', 17', and 21' using

a hybrid functional (the three parameter exchange functional of Becke (B3)219 and the

180

correlation functional of Lee, Yang, and Parr (LYP)340 (B3LYP) as implemented in the

Gaussian 03 program suite.218 The LANL2DZ basis set were used for all atoms within

16', 16-Me', 17', and 21'.341 The geometry was optimized using atomic coordinates from

the crystal structure as an initial input and calculations for the vibrational frequencies

were performed alongside the geometry optimization to ensure the stability of the

ground state as denoted by the absence of imaginary frequencies. Molecular orbital

pictures were generated from Gabedit at their reported isovalues.

5.5.5 Synthesis of [CF3-ONO]W=CH(Et)(OtBu) (16)

A benzene solutions (2 mL) of 8 (376.4 mg, 0.711 mmol) and W≡C(Et)(OtBu)3

(315.9 mg, 0.711 mmol) were combined and stirred for 0.5 h. The solvent was

evaporated and the residual solid was placed under vacuum for 4 h. Single crystals of

16 were grown from a pentane solution at -35 °C (0.352 g, 60%). 1H NMR (C6D6, 300

MHz, 25 °C): δ = 7.72 (s, 2H, Ar-H), 7.36 (t, 1H, 3J = 7.64 Hz, WCHCH2CH3), 6.81 (d,

1H, 3J = 8.49 Hz, Ar-H), 6.66 (d, 1H, 3J = 8.21 Hz, Ar-H), 6.60 (d, 1H, 3J = 9.06 Hz, Ar-

H), 6.59 (d, 1H, 3J = 8.49 Hz, Ar-H), 5.08 (ddq, 1H, 2J = 15.0 Hz, 3J = 7.36 Hz, 3J = 7.36

Hz, WCHC(H’)(H)CH3), 4.79 (ddq, 1H, 2J = 15.0 Hz, 3J = 7.36 Hz, 3J = 7.36 Hz,

WCHC(H’)(H)CH3), 2.00 (s, 3H, CH3’), 1.96 (s, 3H, CH3), 1.21 (s, 9H, OC(CH3)3, and

0.77 (t, 3J = 7.36 Hz, WCHCH2CH3) ppm. 19F{1H} NMR (C6D6, 300 MHz, 25 °C): δ = -

71.2 (q, 3F, 4J = 9.61 Hz), - 71.5 (q, 3F, 4J = 12.0 Hz), - 73.9 (q, 3F, 4J = 9.60 Hz), and -

77.2 (q, 3F, 4J = 9.61 Hz) ppm. 13C{1H} NMR (C6D6, 300 MHz, 25 °C): δ = 260.3 (s,

WCHCH2CH3, with satellites 1J(13C, 183W) = 173.1 Hz), 146.8 (s, Ar C), 145.8 (s, Ar C),


(s, Ar C), 124.5 (s, Ar C), 124.3 (s, Ar C), 90.3 (s, OCMe3), 33.6 (s, WCHCH2CH3), 29.8

181

(s, OC(CH3)3), 21.4 (s, WCHCH2CH3), 21.0 (s, Ar-CH3’), and 20.8 (s, Ar-CH3) ppm.

Anal. Calcd. for C27H27F12NO3W (825.33 g/mol): C: 39.29%; H: 3.30%; N: 1.70%,

Found; C: 39.25%; H: 3.37; N: 1.58%.

5.5.6 Synthesis of {[CF3-ONO]W≡C(Et)(OtBu)}{MePPh3} (17)

A pentane solution of CH2PPh3 (131.5 mg, 0.476 mmol, 1.6 equiv) was filtered

prior to drop wise addition to a stirring pentane solution of 16 (243.4 mg, 0.295 mmol, 1

equiv). Red oil formed upon complete addition and the reaction mixture was triturated in

the pentane solution for 6 h to yield a yellow powder. The powder was filtered, washed

with pentane, and dried overnight (0.170 g, 83%). 1H NMR (C6D6, 300 MHz, 25 °C): δ =

7.81 (s, 1H, Ar-H), 7.66 (s, 1H, Ar-H), 7.51 (d, 1H, Ar-H, 3J = 8.35 Hz), 7.20 (d, 1H, Ar-

H, 3J = 8.95 Hz), 7.01 (b, (C6H5)3PCH3), 6.98 (b, (C6H5)3PCH3) 6.92 (dd, 1H, Ar-H, 3J =

8.65 Hz, 4J = 1.64 Hz), 6.80 (dd, 1H, Ar-H, 3J = 8.35 Hz, 4J = 1.64 Hz), 4.35 (q, 2H,

WCCH2CH3, 3J = 7.61 Hz), 2.44 (d, 3H, (C6H5)3PCH3,

2J =13.31 Hz), 2.16 (s, 3H, Ar-

CH3), 2.09 (s, 3H, Ar-CH3’), 1.63 (s, 9H, OC(CH3)3), and 0.80 (t, 3H, WCCH2CH3, 3J =

7.64 Hz) ppm. 31P{1H} NMR (C6D6, 300 MHz, 25 °C): δ = 21.8 ppm. 19F{1H} NMR (C6D6,

300 MHz, 25 °C): -69.38 (q, 3F, 4J = 8.30 Hz), -71.24 (q, 3F, 4J = 10.38 Hz), -74.08 (q,

3F, 4J = 10.38 Hz), and -76.38 (q, 3F, 4J = 8.30 Hz) ppm. Anal. Calcd. for

C46H44F12NO3PW (1096.64 g/mol): C: 50.15%; H: 4.03%; N: 1.27%, Found; C: 50.15%;

H: 3.96; N: 1.32%.

5.5.7 Preparation of [CF3-ONO]W=C(CH3)(Et)(OtBu) (18)

To a benzene (1 mL) solution of 17 (0.024 g, 2.1 x10-5 mol) was added MeOTf

(0.004 mg, 2.1 x10-5 mol). The reaction solution turned immediately from red to brown

and the solvent was removed in vacuo. The residue was dissolved in Et2O and filtered

182

to remove a colorless precipitate (MePPh3OTf). The solvent was removed again in

vacuo and the residue was dissolved in pentane and filtered. Removal off all volatiles

from the filtrate provides 18 along with intractable impurities (<10%) thus precluding

combustion analysis. Multinuclear and 2D NMR techniques provide the unambiguous

characterization of 18 and the absolute assignment of all 1H and 13{1H} NMR

resonances. 1H NMR (C6D6, 500 MHz, 25 °C): δ = 7.67 (s, 1H, Ar-H), 7.65 (s, 1H, Ar-

H), 6.76 (d, 1H, 3J = 8.50 Hz, Ar-H), 6.71 (d, 1H, 3J = 8.50 Hz, Ar-H), 6.61 (d, 1H, 3J =

8.80 Hz, Ar-H), 6.51 (d, 1H, 3J = 8.80 Hz, Ar-H), 4.87 (s, 3H, WC(CH3)CH2CH3), 4.62

(m, 1H, WCHC(H’)(H)CH3), 4.50 (m, 1H, WCHC(H’)(H)CH3), 1.93 (s, 6H, CH3), 1.19 (s,

9H, OC(CH3)3, and 0.70 (t, 3J = 7.33 Hz, WCHCH2CH3) ppm. 19F{1H} NMR (C6D6, 500

MHz, 25 °C): δ = -76.3 (q, 3F, 4J = 8.48 Hz), -75.6 (q, 3F, 4J = 9.69 Hz), -71.1 (q, 3F, 4J

= 9.69 Hz), and -70.8 (q, 3F, 4J = 8.48 Hz) ppm. 13C{1H} NMR (C6D6, 500 MHz, 25 °C):

δ = 284.3 (s, WC(CH3)CH2CH3), 145.3 (s, Ar C), 142.8 (s, Ar C), 134.2 (s, Ar C), 133.2

(s, Ar C), 131.9 (s, Ar C), 131.6 (s, Ar C), 127.3 (s, Ar C), 126.9 (s, Ar C), 126.5 (s, Ar

C), 124.0 (s, Ar C), 122.8 (s, Ar C), 89.9 (s, -OC(CH3)), 34.0 (s, WC(CH3)CH2CH3), 29.1

(s, OC(CH3)3), 23.5 (s, WC(CH3)CH2CH3), 20.4 (s, Ar-CH3’), 20.2 (s, Ar-CH3), and 18.4

(s, WC(CH3)CH2CH3) ppm.

5.5.8 Preparation of [CF3-ONO]W=CH(Et)(OSiMe3) (19)

To a diethyl ether (1 mL) solution of 17 (0.143 g, 1.30 x10-4 mol) was added

Me3SiOTf (0.029 mg, 1.31 x10-4 mol). The reaction solution turned immediately from red

to brown and a colorless precipitate formed (MePPh3OTf). The solid was removed by

filtration and the filtrate was reduced to provide a brown oil. The product was

immediately re-dissolved in C6D6 to prevent decomposition. The product was found to

183

decompose when left as an oil for several hours, thus precluding combustion analysis.

However, the complex was stable long enough in solution to be characterized by

multinuclear and 2D NMR techniques, thus providing its unambiguous assignment. 1H

NMR (C6D6, 500 MHz, 25 °C): δ = 7.68 (s, 1H, Ar-H), 7.66 (s, 1H, Ar-H), 7.20 (t, 1H,

W=CHCH2CH3, 3J = 7.04 Hz), 6.71 (d, 1H, Ar-H, 3J = 8.21 Hz), 6.61 (d, 1H, Ar-H, 3J =

8.21 Hz), 6.53 (d, 1H, Ar-H, 3J = 8.21 Hz), 6.51 (d, 1H, Ar-H, 3J = 8.21 Hz), 5.28 (m, 1H,

WCHC(H’)(H)CH3), 4.91 (m, 1H, WCHC(H’)(H)CH3), 1.97 (s, 3H, Ar-CH3), 1.93 (s, 3H,

Ar-CH3’), 0.67 (t, 3H, WCHCH2CH3, 3J = 7.33 Hz), and 0.12 (s, 9H, OSi(CH3)3) ppm.

19F{1H} NMR (C6D6, 500 MHz, 25 °C): -69.38 (q, 3F, 4J = 9.61 Hz), -71.24 (q, 3F, 4J =

9.61 Hz), -74.08 (q, 3F, 4J = 9.61 Hz), and -76.38 (q, 3F, 4J = 9.61 Hz) ppm. 13C{1H}

NMR (C6D6, 500 MHz, 25 °C): δ = 262.1 (s, WCHCH2CH3), 145.8 (s, Ar C), 145.0 (s, Ar


126.9 (s, Ar C), 126.4 (s, Ar C), 123.7 (s, Ar C), 123.6 (s, Ar C), 123.1 (s, Ar C), 31.3 (s,

WCHCH2CH3), 20.6 (s, WCHCH2CH3), 20.2 (s, Ar-CH3’), 20.0 (s, Ar-CH3), and -0.1 (s,

OSi(CH3)3) ppm.

5.5.9 Synthesis of [CF3-ONO]W(O)(nPr) (20)

To a 2.0 mL benzene solution of 16 (398 mg, 4.82 x10-4 mol) was added

trimethylsilyl triflate (1 mg, 4.5 x10-6 mol) in benzene (1 mL). The solution changed from

reddish-brown to aquamarine blue over the period of 2 h. The solution was evaporated

in vacuo to remove solvent and trimethylsilyl triflate providing an oil. Crystals of 20

formed from the oil after 3 h. The crystals were removed by spatula (0.274 g, 74.6%). 1H

NMR (C6D6, 300 MHz, 25 °C): δ = 7.52 (s, 2H, Ar-H), 6.73 (d, 1H, Ar-H, 3J = 8.21 Hz),

6.68 (d, 1H, Ar-H, 3J = 8.80 Hz), 6.61 (d, 1H, Ar-H, 3J = 8.21 Hz), 6.52 (d, 1H, Ar-H, 3J =

184

8.80 Hz), 3.03-2.97 (m, 2H, WCH2CH2CH3), 2.81-2.52 (m, 2H, WCH2CH2CH3), 1.92 (s,

3H, Ar-CH3), 1.88 (s, 3H, Ar-CH3), and 0.92 (t, 3H, WCH2CH2CH3, 3J = 7.33 Hz) ppm.

19F{1H} NMR (C6D6, 300 MHz, 25 °C): -71.17 (q, 3F, 4J = 8.48 Hz), -71.77 (q, 3F, 4J =

9.69 Hz), -75.55 (q, 3F, 4J = 9.69 Hz), and -76.38 (q, 3F, 4J = 8.48 Hz) ppm. 13C{1H}

NMR (C6D6, 300 MHz, 25 °C): δ 146.5 (s, Ar), 145.5 (s, Ar), 135.5 (s, Ar), 133.9 (s, Ar),

132.8 (s, Ar-H), 127.5 (s, Ar-H), 125.4 (s, Ar), 123.0 (s, Ar-H) , 82.7 (s, WCH2CH2CH3,

with satellites 1J(13C, 183W) = 109.1 Hz), 26.9 (s, WCH2CH2CH3), 21.0 (Ar-CH3), 20.7 (s,

WCHCH2CH3), and 19.3 (s, Ar-CH3’) ppm. Anal. Calcd. for C24H22F12NO3W (769.22

g/mol): C: 36.76%; H: 2.83%; N: 1.79%, Found; C: 36.67%; H: 2.87; N: 1.79%.

185

Figure 5- 1. Amido p-orbital aligned with dxy and amido p-orbital rotated out of alignment.

Figure 5- 2. Two possible resonance contributions for an enamine and amidoalkylidene.

Figure 5- 3. Truncated qualitative orbital diagram of the bonding analogy between enamines374 and amidoalkylidenes.

186

Figure 5- 4. Push-pull synergetic effect of the [CF3-ONO]3- pincer-type ligand.


Figure 5- 6. Molecular structure of [CF3-ONO]W=CH(Et)(OtBu) (16) with ellipsoids

drawn at the 50% probability level, and hydrogen atoms removed for clarity.

187


Figure 5- 8. Methylation of 17 to form 18.

Figure 5- 9. Isobutylene expulsion from 17 to form 19.

188

Figure 5- 10. Lewis acid catalyzed isobutylene expulsion from 16 to form 20.

Figure 5- 11. Molecular structure of [CF3-ONO]W(O) nPr (20) with ellipsoids drawn at the 50% probability level, and hydrogen atoms removed for clarity.

189

Figure 5- 12. Geometry optimized structures for 16', 16-Me', and 17'.

Table 5- 1. Selected bond lengths (Å) for the single crystal X-ray structure of 9 and DFT geometry optimized structures of 16', 16-Me', and 17'.

Bond Lengths 16 16' 16-Me' 17'

W1-O1 1.953(2) 1.982 1.884 2.001

W1-O2 1.931(2) 1.953 1.880 1.991

W1-O3 1.819(2) 1.836 2.136 1.917

W1-N1 1.993(3) 2.013 1.982 2.142

W1-C21 1.882(4) 1.898 1.986 1.769

C21-C22 1.499(5) 1.519 1.507 1.493

O3-C28 1.498

190

Table 5- 2. Selected bond angles (°) for the single crystal X-ray structure of 9 and DFT geometry optimized structures of 16', 16-Me', and 17'.

Angles 16 16' 16-Me' 17'

O1-W1-O2 144.95(11) 145.68 156.17 146.18

O1-W1-C21 104.44(13) 103.65 99.44 103.39

N1-W1-O3 154.64(11) 155.42 151.23 153.28

N1-W1-C21 99.81(14) 97.98 101.36 98.06

O2-W1-C21 109.41(13) 108.38 104.08 106.26

O3-W1-C21 105.50(13) 106.48 107.40 108.65

C22-C21-W1 137.2(3) 137.44 134.18 176.20

C28-O3-W1 111.50

Figure 5- 13. The HOMO, HOMO(-1), and HOMO(-2) orbitals of 17' (Isovalue = 0.051687).

191

Figure 5- 14. The HOMO, HOMO(-1), and HOMO(-2) orbitals of 17'; and the HOMO, HOMO(-1), and HOMO(-2) orbitals of 21' (Isovalue = 0.051687).

192

Figure 5- 15. Proposed mechanism for isobutylene expulsion from 17.

193

Figure 5- 16. Proposed mechanism for isobutylene expulsion from 16 (LA = Me+, Me3Si+, and B(C6F5)3.

Figure 5- 17. Truncated X-ray structure of 16 and geometry optimized structure 16-Me' illustrating the 77° rotation of the W=C bond.

194

Figure 5- 18. The HOMO, HOMO(-1), and HOMO(-5) orbitals of 16-Me' (Isovalue = 0.051687).

195

CHAPTER 6 FUTURE WORK TOWARDS AN ACTIVE ALKYNE METATHESIS CATALYST

FEATURING A NEW TRIANIONIC ONO PINCER-TYPE LIGAND.

6.1 Introduction

Chapters 4 and 5 introduce the trianionic [CF3-ONO] pincer-type ligand

supported tungsten alkylidyne. The [CF3-ONO] ligand with its unique push-pull

electronic combination serves a unique role in polarizing W-C multiple bonds. This

electronic environment coupled with the poor steric groups on the pendant arm renders

the tungsten alkylidyne complex as an unsuitable catalyst for alkyne metathesis

(Chapter 4), but promotes an unusual C−H bond activation from a tungsten alkylidyne

and alkylidene (Chapter 5).

More recent work centers on the creation of a new trianionic ONO pincer-type

ligand for alkyne metathesis. Our goal is to destabilize the metallacyclobutadiene by

increasing the peripheral steric bulk and avoiding any inorganic enamine interaction.

Figure 6-1 depicts the proposed ONO ligand to support an alkyne metathesis catalyst. A

notable feature is the bulky tBu on the pendant arms that should provide steric pressure

on the WC3 ring of the tungstenacyclobutadiene intermediate. Additionally, the central

N-donor moiety is a pyrrole. The nitrogen lone pair, which previously led to the inorganic

enamine interaction, should be consumed within the pyrroles aromaticity.


6.2.1 Progess towards the Synthesis of [pyr-ONO]H3

Our initial approach to preparing the [pyr-ONO] ligand is depicted in Figure 6-2

(red arrows). Combining a CH2Cl2 solution of succinyl dichloride with a 10% NaOH

solution of the selected phenol yields the the diester product as intended.405 However,

the second steps involving a Friedel-Craft rearrangement produces the respective 1,4-

196

bis(2-hydroxyphenyl)butane-1,4-dione,406, 407 but also removes the ortho R-groups

(Figure 6-2). Replacing the R-substituent in the ortho substituent upon subjecting 1,4-

bis(2-hydroxyphenyl)butane-1,4-dione to a Friedel-Craft alkylation with 2-chloro-2-

methylpropane was unsuccessful. Additionally, using TiCl4 instead of AlCl3 does not

induce any rearrangement. As such, without the sterically R-groups attached, a new

synthetic route was explored.

The second approach to synthesize the [py-ONO] ligand involves a Suzuki

coupling of dibromopyrrole with (3-(tert-butyl)-2-methoxyphenyl)boronic acid (Figure 6-

3). The reaction proceeds at 95 °C over 18 h. Resulting workup in acidic media removes

the BOC protecting group. Compound 22 is purified by crystallization from a

concentrated 2-propanol solution. In the 1H NMR spectrum of 22, the pyrrole NH proton

appears as a broaden signal at 9.90 ppm, and the corresponding pyrrole aromatic

proton resonates as a doublet (4J = 2.68 Hz) at 6.55 ppm. In the alkyl region, the

methoxy and the tert-butyl protons resonate at 3.57 and 1.46 ppm, respectively.

The methyl protecting groups of 22 are easily removed with excess BBr3 in

CH2Cl2 at 0 °C. The 1H NMR spectrum of the crude reaction mixture confirms the

removal of the methyl group. However, the resulting product is not the protio-ligand.

The proton signals attributable to the NH and OH are not present in the 1H NMR

spectrum. Rather a boron atom inserted inside the tridentate ligand. Mass spectroscopy

confirms a single boron atom and the identity of complex 23. The 1H NMR spectrum of

23 contains the pyrrole C−H protons as a singlet at 6.71 and the tert-butyl groups now

resonate at 1.52 ppm.

197

Attempts to remove the boron atom from 23 with HCl or KOtBu were unsucessful.

Using the strong base n-BuLi appears to remove the boron atom, however, the protio-

ligand was not able to be separated from intractable impurities.

Future work involves exploring new methyl deprotecting agents with complex 22. One

example that we are currently looking into is 2-(dimethylamino)ethanethiol.

6.3 Experimental




toluene, diethyl ether (Et2O), dichloromethane, tetrahydrofuran (THF), and 1,2-

dimethoxyethane (DME) were dried using a GlassContour drying column. Benzene-d6

(Cambridge Isotopes) was dried over sodium-benzophenone ketyl, distilled or vacuum

transferred, and stored over 4 Å molecular sieves. tert-Butyl 2,5-dibromo-1H-pyrrole-1-

carboxylate408 and (3-(tert-butyl)-2-methoxyphenyl)boronic acid409 were prepared

according to published literature procedures. All other reagents were purchased from

commercial vendors and used without further purification.






6.3.3 Synthesis of 2,5-bis(3-(tert-butyl)-2-methoxyphenyl)-1H-pyrrole

Inside an argon-filled glove box, a toluene solution (15 mL) containing (3-(tert-

butyl)-2-methoxyphenyl)boronic acid (0.660 g, 3.17 x10-3 mol, 2.3 equiv.),

198

tetrakis(triphenylphosphine)-palladium(0) (0.159 g, 1.38 x10-4 mol, 0.10 equiv.), Na2CO3

(1.16 g, 1.09 x10-2, 7.9 equiv.), KCl (0.308 g, 4.13 x10-3 mol, 3 equiv.), and tert-butyl

2,5-dibromo-1H-pyrrole-1-carboxylate (0.448 g, 1.38 x10-3 mol, 1 equiv.) were prepared.

The reaction flask was fitted with a Liebig condenser and y-adapter prior to exiting the

glovebox and attached to the argon Schlenk line. Under counter argon pressure, 15 mL

of degassed ethanol-water (2:1) solution was added to the reaction flask. The reaction

mixture was heated at 96° C with stirring for 20 h, during that time the solution changes

from yellow to orange-red color. The reaction mixture was allowed to cool, and then

solvent was removed under reduced pressure. The residue was dissolved in CH2Cl2 (15

mL) and washed with water and brine. The organic layer was dried with MgSO4, and the

solvent was removed under reduced pressure. To the residue, 20 mL of hexanes was

added to precipitate a white solid. The mixture was stirred for 0.5 h before filtering off

the white solid. The collected filtrate was reduced under vacuum to yield an orange oil

containing the BOC protected pyrrole. The Boc protecting group is easily removed upon

stirring the residue with 10 mL of 4 M HCl in 1,4-dioxane at 45° C for 18 h. The solvent

was removed under reduced pressure. The residue was dissolved in DCM, washed with

saturated solution of Na2CO3 and then water. The organic layer was dried with MgSO4

prior to removing the solvent under reduced pressure. The purple oily residue was

dissolved in minimal 2-propanol (5 mL). Cooling the 2-propanol solution precipitates

crystals of the product, 2,5-bis(3-(tert-butyl)-2-methoxyphenyl)-1H-pyrrole (Yield =

0.219, 47%). 1H NMR (CDCl3, 500 MHz, 25° C): δ = 9.90 (b, 1H, NH), 7.42 (dd, 2H, 3J =

7.57 Hz, 4J = 1.71 Hz, Ar-H), 7.24 (dd, 2H, 3J = 7.93 Hz, 4J = 1.71 Hz, Ar-H), 7.07 (t, 2H,

3J = 7.81 Hz, Ar-H), 6.55 (d, 2H, 4J = 2.68 Hz, Ar-H), 3.57 (s, 6 H, -OCH3), 1.46 (s, 18 H,

199

-C(CH3)3) ppm. 13C{1H} NMR (CDCl3, 126 MHz, 25° C): δ = 156.3 (s, Ar C), 143.4 (s, Ar

C), 130.0 (s, Ar C), 127.4 (s, Ar C), 126.9 (s, pyr C), 125.5 (s, Ar C), 123.8 (s, Ar C),

108.1 (s, pyr C), 60.8 (s, -OCH3), 35.2 (s, -C(CH3)3), 31.0 (s, -C(CH3)3) ppm. ESI-MS:

371.21 [1 + H]+.

200

Figure 6- 1. Proposed alkyne metathesis catalyst featuring a trianionic [pyr-ONO] pincer-type ligand.

Figure 6- 2. Proposed synthesis of [pyr-ONO] pincer-type ligand (red arrows) and actual outcome.

201

Figure 6- 3. Proposed synthesis of [pyr-ONO] pincer-type ligand (red arrows) and actual outcome.

202

APPENDIX A SUPPORTING INFORMATION

A.1 NMR Data

Figure A- 1. 1H NMR Spectra of 1 obtained in THF-d8.

Figure A- 2. 13C{1H} NMR Spectra of 1 obtained in THF-d8

203

Figure A- 3. 1H NMR spectrum of 2 in C6D6.

204


205


206

Figure A- 6. 1H NMR of 5 in C6D6.

Figure A- 7. 1H NMR of 5 dissolved in THF-d8 to form 2 (characteristic peaks = 8.20, -7.44, -13.23 ppm) and 3.

090313A

40 35 30 25 20 15 10 5 0 -5 -10 -15 -20 -25 -30 -35

Chemical Shift (ppm)

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

0.09

0.10

0.11

0.12

0.13

0.14

Norm

alized Inte

nsity

28.7

2

16.9

6

13.3

8 8.2

7

1.7

90.3

0

-30.5

7

090617B

35 30 25 20 15 10 5 0 -5 -10 -15 -20 -25 -30 -35


0.05

0.10

0.15

Norm

alized Inte

nsity

7.4

3

3.5

82.3

71.6

7

-8.4

5

-13.5

4

207

Figure A- 8. 1H NMR of 6 in C6D6 with 0.01 mL THF-d8.

Figure A- 9. 1H NMR of 5 (2.43 x10-5 mol) in C6D6 (red) and with OPPh3 (5.82 x10-5) in C6D6 (blue).

6/9/2010 10:51:48 AM

Acquisition Time (sec) 1.2800 Comment 1H Standard Parameters Date Jun 8 2010

Date Stamp Jun 8 2010 File Name C:\Users\Matthew\Documents\(OCO)Cr(O)(CH2PPh3)\100608A.fid\fid

Frequency (MHz) 300.15 Nucleus 1H Number of Transients 16 Original Points Count 64000

Points Count 65536 Pulse Sequence s2pul Receiver Gain 22.00 Solvent Benzene

Spectrum Offset (Hz) 2061.7407 Spectrum Type STANDARD Sweep Width (Hz) 50000.00 Temperature (degree C) 25.000

VerticalScaleFactor = 1100608A.esp

15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 -1 -2 -3 -4 -5


0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

Norm

alized Inte

nsity

0.8

51.1

01.2

01.3

21.4

1

2.1

2

3.2

53.5

2

7.0

2

O

O

CrPh3P

O

NONAME01

20 15 10 5 0 -5 -10 -15 -20 -25 -30


-12

-10

-8

-6

-4

-2

0

2

4

6

8

10

12

Norm

alized Inte

nsity

208

Figure A- 10. Labelling scheme for 1H and 13C NMR peaks.

209

Table A- 1. 1H, 13C, 19F and 15N chemical shifts in compounds 8-15.

Compd. 8 15 16 17 18 19 20a 21

C1 80.6 82.8 83.6 86.2 86.2 80.8 81.2 80.8 C2 120.9 123.5 121.0 135.5 135.3 124.9 124.8 125.0 C3 143.0 146.5 154.5 152.4 151.0 146.0 145.7 144.6 C4 126.1 123.9 122.9 nm nm 127.7 126.5 125.8 C5 132.1 131.0 130.3 130.6 131.0 131.9 132.1 132.0 C6 134.4 133.6 122.6 130.8 132.5 131.9 131.8 131.4 C7 128.3 126.2 127.0 127.5 127.5 126.9 127.1 126.9 C8 123.2 124.6 nm nm nm nm 123.9 123.3

C9 123.3 123.7 nm 124.8 124.5 nm 123.5 123.9 C10 20.2 20.1 20.5 20.7 20.6 20.3 20.3 20.3 C11 80.6 84.3 85.4 85.4 84.9 81.6 = C1 81.8 C12 120.9 127.5 131.5 118.0 119.3 124.5 = C2 124.2 C13 143.0 145.4 155.5 151.4 150.5 144.9 = C3 145.1 C14 126.1 123.9 126.2 121.1 122.3 127.1 = C4 126.0 C15 132.1 133.0 130.2 130.8 131.3 132.4 = C5 132.4 C16 134.4 134.4 127.8 126.2 128.7 132.4 = C6 131.9 C17 128.3 127.3 127.2 127.1 126.8 127.3 = C7 127.3

C18 123.2 124.3 nm 124.5 124.3 nm =C8 123.5 C19 123.3 123.7 nm 124.7 123.7 nm = C9 123.5 C20 20.2 20.3 20.7 20.3 20.2 20.4 = C10 20.4 C21 - 262.6 286.0 308.6 311.5 242.3 252.0 238.6 C22 - 41.0 49.4 49.5 49.9 138.2 138.2 142.8 C23 - 35.0 33.7 33.7 33.6 244.6 = C21 252.8 C24 - 90.4 77.1 120.1 79.3 42.3 43.5 42.0 C25 - 29.2 33.5 nm 13.4 30.2 30.1 31.0 C26 - 8.5 8.3 - 15.8 11.6 26.9 C27 - 118.7 118.6 - 138.2 = C24 31.0

C28 - 132.5 132.6 - 129.9 = C25 24.0 C29 - 129.9 130.0 - 128.3 - 26.0 C30 - 134.6 134.7 129.2 - 29.5 C31 - - - - - - 35.5 N 66.2 225.7 149.3 165.5 178.3 208.6 204.4 202.1

H4 6.69 6.54 7.05 7.27 7.05 7.00 7.02 7.07 H5 6.63 6.33 6.72 6.85 6.80 6.67 6.80 6.80 H7 7.47 7.68 7.59 7.77 7.73 7.58 7.57 7.65

H10 1.83 1.97 2.03 2.06 2.01 1.95 1.96 2.00 H14 6.69 6.54 7.44 6.91 6.70 7.05 = H4 7.06

H15 6.63 6.78 6.90 6.74 6.70 6.84 = H5 6.83 H17 7.47 7.67 7.73 7.62 7.65 7.60 = H7 7.57

210

Table A- 1. Continued

Compd. 8 15 16 17 18 19 20a 21

H20 1.83 1.91 2.12 2.02 2.00 1.98 = H10 1.96 H21 6.42 - - - - - - H23 1.12 1.15 1.02 0.80 - - - H24 - - - 3.58, 3.78 - - - H25 1.21 1.64 - 0.84 1.15 1.15 1.13 H26 - 2.33 2.27 - 2.78 2.93 3.76, 3.30 H27 - - - - - - 1.30, 1.30 H28 - 6.99 7.10 - 7.02 = H25 1.13, 0.90

H29 - 6.99 7.15 - 7.09 - 1.15, 0.90 H30 - 7.07 7.23 - 6.86 - 1.45, 1.35 H31 - - - - - - 3.12, 3.61 F8 e -74.16 -71.11 -68.95 -68.50 -68.74 -71.57 -71.39 -75.72 F9 -75.69 -73.03 -72.15 -76.19 -76.71 -75.55 -76.05 -71.89

F18 -74.16 -70.29 -66.43 -72.75 -71.30 -70.99 = F8 -76.23 F19 -75.69 -76.90 -73.95 -73.38 -74.94 -76.02 = F9 -70.59 F24 - - -76.22 - - - - F25 - - -77.68 - - - -

The fluorine signals in compounds 15-21 are quartets with a typical coupling constant of 9-10 Hz. “nm” abbreviates signals too weak to measure.

a Complex 20 is C2-symmetric resulting in equivalent positions.

Compounds 8-15 were characterized by 1H, 13C, 19F and 15N NMR. The chemical

shifts are presented in Table A- 1. The assignments were made primarily based on the

cross-peaks seen in the 1H-13C gHMBC spectra. The chemical shifts of the fluorinated

carbons were measured in the 19F-13C gHSQC spectra, and their assignment to

positions 8 and 9 vs. 18 and 19 was made based on the long-range coupling of the

fluorines to the quaternary carbon two bonds away, coupling seen in the 19F-13C

gHMBC spectra. The chemical shift of the 15N was measured in the 1H-15N gHMBC

spectrum, where it shows cross-peaks with H4 and H14. No stereochemical

assignments were made, i.e. H7 and H17 are interchangeable, as well as C8 and C9. In

Table A- 1, C1 and C2 were assigned as the most shielded of the pairs C1, C11 and

C2, C12; F8 and F9 were assigned as the most deshielded of the pairs F8, F18 and F9,

F19.

211

In a typical assignment procedure, H7 displays cross-peaks with a carbon around

20 ppm, assigned as C10, with a carbon around 80-85 ppm, assigned as C1, with a

carbon around 150-160 ppm, assigned as C3 and with a carbon around 130 ppm,

assigned as C5. H10, H5 and C7 were then identified by one-bond correlations, or by

the couplings H10-C5, H10-C7, H5-C7. H4 was identified as coupling with H5, or by its

coupling with C6, the third carbon coupling with H10. One coupling of F8 or F9 with C1

was sufficient to identify these fluorines, since the pairs H8-F9 and F18-F19 are

revealed by selective decoupling in the 19F spectra. The assignments for the positions

11-20 was done in a similar way to the one for positions 1-10. The proton signals for

positions 21-27 can be assigned based on their intensity and multiplicity. The carbons in

these positions were assigned based on their one-bond and long-range couplings to

protons.

The 13C chemical shifts difference in positions 3/13and 6/16 as well as the 15N

chemical shifts difference between compounds 16, 17, and 18 on one hand and 15, 19,

20 and 21 on the other suggest that in 16, 17, and 18 the nitrogen is more ‘amino-like’

while in 15, 19, 20 and 21 is more ‘imine-like’.

212

Figure A- 11. 1H NMR (CDCl3, 300 MHz) spectrum of 8.

Figure A- 12. Variable Temperature 19F{1H} NMR (CDCl3, 300 MHz) spectrum of 8 at 25 °C (blue), 35 °C (green), 45 °C (gray), and 55 °C (red).

110312A

8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0


0

8

16

24

32

40

48

56

64

72

80

88

96

Norm

alized Inte

nsity

5.921.932.00

2.3

6

6.8

16.8

4

7.1

67.1

87.3

7

vt1.esp

-72.5 -73.0 -73.5 -74.0 -74.5 -75.0 -75.5 -76.0 -76.5 -77.0 -77.5 -78.0 -78.5


-300

-250

-200

-150

-100

-50

0

50

100

Norm

alized Inte

nsity

213

Figure A- 13. 13C{1H} NMR (CDCl3, 300 MHz) spectrum of 8.

Figure A- 14. 13C{19F} NMR (CDCl3, 300 MHz) spectrum of 8.

H1-C13-Decoupled

160 140 120 100 80 60 40 20 0


0

8

16

24

32

40

48

56

64

72

80

88

96

Norm

alized Inte

nsity

20.9

8

120.7

8

126.0

3128.4

5132.0

6134.3

1

142.8

1

F19-C13-Decoupled

180 170 160 150 140 130 120 110 100 90 80 70 60 50 40 30 20


0

8

16

24

32

40

48

56

64

72

80

88

96

Norm

alized Inte

nsity

80.3

0

122.8

4

214

Figure A- 15. 1H-13C gHMBC (C6D6, 500 MHz) spectrum of 8.

Figure A- 16. 1H-13C gHMBC (C6D6, 500 MHz) spectrum of 8, expanded.

215

Figure A- 17. 1H-15N gHMBC (C6D6, 500 MHz) spectrum of 8.

Figure A- 18. 19F-13C gHSQC (C6D6, 500 MHz) spectrum of 8.

216


120204B

-68 -69 -70 -71 -72 -73 -74 -75 -76 -77 -78


200

400

600

800

1000

1200

1400

1600

1800

2000

Norm

alized Inte

nsity

-70.6

5-7

0.6

9-7

0.7

2-7

0.7

5

-71.4

7-7

1.5

0-7

1.5

4-7

1.5

7

-73.3

9-7

3.4

2-7

3.4

6-7

3.5

0

-77.2

6-7

7.2

9 -77.3

2-7

7.3

5

Figure A- 20. 19F{1H} NMR spectrum of 9 in C6D6.

120204A

8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5


0

200

400

600

800

1000

1200

1400

1600

1800

2000N

orm

alized Inte

nsity

8.086.000.961.081.98

1.1

51.2

4

1.9

41.9

9

6.4

46.5

56.5

86.6

46.6

76.7

96.8

2

7.6

97.7

1

217

Figure A- 21. 1H{13C} gHSQC NMR spectrum of 9 in C6D6.

Figure A- 22. 1H{13C} gHMBC NMR spectrum of 9 in C6D6.

218

Figure A- 23. 1H{15N} gHMBC NMR spectrum of 9 in C6D6.

Figure A- 24. 19F{1H} NMR spectra of 9 in C6D6 (bottom) and with selective decoupling

(top).

219

Figure A- 25. 19F{13C} gHMBC NMR spectrum of 9 in C6D6, expanded.

Figure A- 26. 19F{13C} gHSQC NMR spectrum of 9 in C6D6, expanded.

220

Figure A- 27. 19F{13C} gHSQC NMR spectrum of 9 in C6D6, expanded.

120206A

8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5


0

200

400

600

800

1000

1200

1400

1600

1800

2000

Norm

alized Inte

nsity

8.008.143.132.961.1715.671.091.06

7.7

67.6

17.4

87.4

5

7.0

9

7.0

36.9

96.9

36.9

16.7

66.7

3

2.3

82.3

32.1

42.0

6

1.6

6

1.1

7


221

120206B

-65 -66 -67 -68 -69 -70 -71 -72 -73 -74 -75 -76 -77 -78 -79 -80


0

200

400

600

800

1000

1200

1400

1600

1800

2000N

orm

alized Inte

nsity

-68.6

3-6

8.6

5-6

8.6

8-6

8.7

2

-71.1

3-7

1.1

7-7

1.2

0-7

1.2

4

-74.3

4-7

4.3

7-7

4.4

0-7

4.4

4

-76.1

5-7

6.1

8 -76.2

1-7

6.2

5


120206C

40 32 24 16 8 0 -8 -16 -24 -32 -40


200

400

600

800

1000

1200

1400

1600

1800

2000

Norm

alized Inte

nsity

21.5

9

Figure A- 30. 31P{1H} NMR spectrum of 10 in C6D6.

222

Figure A- 31. 1H{13C} gHSQC NMR spectrum of 10 in C6D6.

Figure A- 32. 1H{13C} gHMBC NMR spectrum of 10 in C6D6. The signals at 278.5 and

16.0 in f1 are 8.5 and 286.0, foled.

223



(top).

224


120615AE

8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0


-200

0

200

400

600

800

1000

Norm

alized Inte

nsity

8.986.131.0125.891.04

7.8

37.6

87.3

37.3

27.2

47.2

37.1

47.1

37.1

07.0

96.9

86.9

66.9

16.8

96.8

1

2.3

02.2

82.1

02.0

7

1.0

7


225

120615AB

-68 -69 -70 -71 -72 -73 -74 -75 -76 -77 -78 -79


0

200

400

600

800

1000

1200

1400

1600

1800

2000N

orm

alized Inte

nsity

1.296.093.053.003.00

-68.9

3-6

8.9

6-6

8.9

9-6

9.0

3

-73.1

6-7

3.1

9-7

3.2

2

-73.8

8-7

3.9

1-7

3.9

4-7

3.9

8

-76.6

0-7

6.6

3-7

6.6

8

-78.2

0


120615AD

23.5 23.0 22.5 22.0 21.5 21.0 20.5 20.0


200

400

600

800

1000

1200

1400

1600

1800

2000

Norm

alized Inte

nsity

21.9

8

Figure A- 38. 31P{1H} NMR spectrum of 11 in C6D6.

226


Figure A- 40. 1H{13C} gHMBC NMR spectrum of 11 in C6D6, expanded.

227



228

Figure A- 43. 1H{15N} gHMBC NMR spectrum of 11 in C6D6, expanded.


229

Figure A- 45. 19F{13C} gHSQC NMR spectrum of 11 in C6D6.

120703AA

8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5


0

200

400

600

800

1000

1200

1400

1600

1800

2000

Norm

alized Inte

nsity

11.015.552.001.711.761.03

7.7

77.6

9

7.1

17.0

8 7.0

27.0

0 6.7

4

3.8

73.8

43.8

33.8

13.7

8 3.6

73.6

43.6

33.6

0

2.0

6 2.0

5

0.9

10.8

90.8

5


230

120703AB

-62 -64 -66 -68 -70 -72 -74 -76 -78 -80 -82 -84 -86 -88 -90


0

200

400

600

800

1000

1200

1400

1600

1800

2000N

orm

alized Inte

nsity

-69.1

8-6

9.2

1-6

9.2

4-6

9.2

8

-71.7

5-7

1.7

8-7

1.8

1-7

1.8

5

-75.3

7-7

5.4

1-7

5.4

4-7

5.4

8

-77.1

4-7

7.1

7 -77.2

1-7

7.2

4



231



232



233

Figure A- 53. 1H{15N} gHMBC NMR spectrum of 12 in C6D6, expanded.


(top).

234

Figure A- 55. 19F{13C} gHMBC NMR spectrum of 12 in C6D6.


235

120309AC

7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0


0

200

400

600

800

1000

1200

1400

1600

Norm

alized Inte

nsity

9.035.892.931.012.972.03

7.6

57.6

47.1

97.1

67.1

47.1

3 7.0

87.0

67.0

56.9

26.9

06.8

1

2.7

9

2.0

32.0

1

1.2

1


120309AB

-69 -70 -71 -72 -73 -74 -75 -76 -77 -78


200

400

600

800

1000

1200

1400

1600

1800

2000

Norm

alized Inte

nsity

-71.4

4-7

1.4

7-7

1.5

1-7

1.5

4

-72.0

2-7

2.0

5-7

2.0

9-7

2.1

2

-76.0

0-7

6.0

4-7

6.0

7-7

6.1

1-7

6.5

1 -76.5

4-7

6.5

7


236

120309AD

240 220 200 180 160 140 120 100 80 60 40 20


50

100

150

200

250

300

Norm

alized Inte

nsity

245.3

7243.0

3

146.7

6145.6

1

138.9

4133.1

6130.6

8 128.9

9128.6

8127.8

4126.4

5125.5

9125.2

7

66.2

6

43.0

3

30.9

5

21.1

021.0

116.3

6

Figure A- 59. 13C{1H} NMR spectrum of 13 in C6D6.


237



(top).

238

120613AC_tBuCCMe

8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5


0

200

400

600

800

1000

1200

1400

1600

1800

2000N

orm

alized Inte

nsity

17.745.972.961.982.00

7.6

1

7.0

77.0

5

6.8

46.8

3

2.9

7

2.0

0

1.1

9


120613AB_tBuCCMe

-69 -70 -71 -72 -73 -74 -75 -76 -77 -78


200

400

600

800

1000

1200

1400

1600

1800

2000

Norm

alized Inte

nsity

-71.8

2-7

1.8

5-7

1.8

9-7

1.9

2

-76.4

8-7

6.5

1-7

6.5

5-7

6.5

8


239

120613AE_tBuCCMe

300 280 260 240 220 200 180 160 140 120 100 80 60 40 20 0


0

50

100

150

200

250

300

350

Norm

alized Inte

nsity

252.8

3

146.4

3

138.9

5132.8

7132.5

5128.6

8127.3

0125.5

5

43.2

7

30.8

7

21.0

6

12.3

2



240


120522A

7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5


0

50

100

150

200

250

300

350

400

450

500

550

Norm

alized Inte

nsity

1.993.105.680.960.971.890.97

7.6

97.6

1

7.1

6 7.1

6 7.1

17.0

96.8

96.8

76.8

66.8

5

3.8

33.8

23.8

03.6

83.6

73.6

53.6

53.6

43.3

73.3

53.2

03.1

8

2.0

52.0

1

1.4

91.4

2 1.3

5

1.1

80.9

70.9

50.9

4


241

120522C

-67 -68 -69 -70 -71 -72 -73 -74 -75 -76 -77 -78 -79 -80


200

400

600

800

1000

1200

1400

1600

1800

2000N

orm

alized Inte

nsity

-70.8

7-7

0.9

0-7

0.9

4-7

0.9

7

-72.1

7-7

2.2

0-7

2.2

4-7

2.2

7

-76.0

0-7

6.0

4-7

6.0

7-7

6.5

1-7

6.5

4-7

6.5

8-7

6.6

1


120522B

260 240 220 200 180 160 140 120 100 80 60 40 20


0

50

100

150

200

250

300

350

400

450

500

550

Norm

alized Inte

nsity

253.6

0

239.4

1

147.3

7145.8

9143.5

8

133.1

7132.7

2128.9

2127.8

0126.5

2125.7

9124.9

3

123.1

8

42.7

8

36.3

031.7

531.6

824.7

821.1

0


242



243

Figure A- 73. 19F{13C} gHMBC NMR spectrum of 15 in C6D6.


244

120622J_MeCN_60C

4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0


0

50

100

150

200

250

300

350

400

450

Norm

alized Inte

nsity

0.590.41

3.1

3 1.5

4

1.2

01.1

8

Figure A- 75. 1H NMR spectrum of 12 in C6D6 and 15 equiv. of MeCN. (tBuCCMe =

1.54 and 1.20 ppm; 14 = 3.13 and 1.18 ppm).

Figure A- 76. 19F{1H} NMR spectrum of 12 in C6D6 and 15 equiv. of MeCN (blue) along

with 19F{1H} NMR spectrum of 14 (red)

NONAME02

-67 -68 -69 -70 -71 -72 -73 -74 -75 -76 -77 -78 -79 -80 -81 -82


-400

-200

0

200

400

600

800

1000

1200

1400

1600

1800

2000

Nor

mal

ized

Inte

nsity

245

Figure A- 77. Labelling scheme for 1H and 13C NMR peaks.

Table A- 2. 1H, 13C, 19F and 15N chemical shifts in compounds 8,16-20 in C6D6.

Compd. 8 16 17 a 18

c 19 20

C1 80.6 82.9 83.6 83.8 83.1 84.1

C2 120.9 123.5 121.0 122.8 123.1 123.3

C3 143.0 146.1 154.2 145.3 145.8 145.8

C4 126.1 123.0 123.3 124.0 123.6 124.7

C5 132.1 131.1 130.3 131.6 131.0 132.6

C6 134.4 133.8 123.0 133.2 134.0 132.9

C7 128.3 126.3 127.2 126.9 126.4 126.9

C8 123.2 124.6 125.8 124.2 124.3 nm

C9 123.3 123.6 124.8 123.6 123.4 nm

C10 20.2 20.1 20.5 20.2 20.0 20.0

C11 80.6 83.8 85.6 83.6 84.0 84.6

C12 120.9 126.8 130.9 126.5 126.9 127.4

C13 143.0 145.2 156.3 142.8 145.0 144.8

C14 126.1 123.9 125.0 126.9 123.7 nm

C15 132.1 132.3 129.9 131.9 132.0 132.9

C16 134.4 134.5 127.1 134.2 134.5 134.7

C17 128.3 127.4 127.2 127.3 127.2 126.7

C18 123.2 124.4 125.3 124.0 124.3 nm

C19 123.3 123.8 125.1 123.7 123.5 nm

C20 20.2 20.3 20.7 20.4 20.2 20.2

246


Compd. 8 16 17 a 18

c 19 20

C21 - 259.6 280.6 284.3 262.1 82.0

C22 - 32.9 38.6 34.0 31.3 26.2

C23 - 20.7 17.1 18.4 20.6 18.6

C24 - 89.5 77.8 89.9 - -

C25 - 29.1 33.5 29.1 -0.1 -

N 66.2 232.1 148.3 217.8 234.2 232.5

H4 6.69 6.56 7.30 6.54 6.51 6.48

H5 6.63 6.63 6.90 6.61 6.61 6.65

H7 7.47 7.69 7.76 7.67 7.68 7.49

H10 1.83 1.97 2.21 1.93 1.97 1.90

H14 6.69 6.55 7.61 6.71 6.53 6.70

H15 6.63 6.78 7.04 6.76 6.76 6.59

H17 7.47 7.68 7.92 7.65 7.66 7.48

H20 1.83 1.93 2.28 1.93 1.93 1.87

H21 - 7.32 - - 7.20 2.99, 2.95

H22 - 5.05, 4.76 4.42, 4.38

4.62,

4.50

5.28,

4.91 2.69, 2.58

H23 - 0.74 0.88 0.70 0.67 0.89

H25 - 1.18 1.76 1.19 0.12 -

F8 e -74.16 -71.06 -70.99 -71.10 -71.30 -70.85

F9 -75.69 -73.44 -73.53 -75.63 -73.90 -73.70

F18 -74.16 -70.71 -68.97 -70.83 -70.50 -68.99

F19 -75.69 -76.73 -75.97 -76.28 -76.60 -75.96 a

H26=2.49 ppm, H28=7.12 ppm, H29=16 ppm, H30=7.23 ppm, and C26=8.5 ppm,C27=118.5 ppm,

C28=132.5 ppm, C29=130.0 ppm,

C30=134.6 ppm.

b H26=2.33 ppm, H28=6.99 ppm, H29=6.99 ppm,

H30=7.07 ppm, and C26=8.5 ppm,C27=118.7 ppm, C28=132.5 ppm,

C29=129.9 ppm,

C30=134.6 ppm.

c the

methyl in position 26 has H=4.87 ppm and C=23.5 ppm. d

Not measured, the sample was too dilute. e The fluorine

signals in compounds 16-20 are quartets with a typical coupling constant of 9-10 Hz. In compound 8 the signals are

broad due to a fluxional process in the ligand, as demonstrated by the spectrum at 70 °C.

Compounds 8, 16-20 were characterized by 1H, 13C, 19F and 15N NMR. The

chemical shifts are presented in Table A- 2. The assignments were made primarily

based on the cross-peaks seen in the 1H-13C gHMBC spectra. The chemical shifts of

the fluorinated carbons were measured in the 19F-13C gHSQC spectra, and their

assignment to positions 8 and 9 vs. 18 and 19 was made based on the long-range

coupling of the fluorines to the quaternary carbon two bonds away, coupling seen in the

19F-13C gHMBC spectra. The chemical shift of the 15N was measured in the 1H-15N

247

gHMBC spectrum, where it shows cross-peaks with H4 and H14. In the case of

compounds 16 and 20, it also shows cross-peaks with H21, which confirms the

structural integrity of these compounds. No stereochemical assignments were made,

i.e. H7 and H17 are interchangeable, as well as C8 and C9. In Table A- 2, C1 and C2

were assigned as the most shielded of the pairs C1, C11 and C2, C12; F8 and F9 were

assigned as the most deshielded of the pairs F8, F18 and F9, F19.

In a typical assignment procedure, H7 displays cross-peaks with a carbon around

20 ppm, assigned as C10, with a carbon between 80-85 ppm, assigned as C1, with a

carbon between 150-160 ppm, assigned as C3 and with a carbon at approx 130 ppm,

assigned as C5. H10, H5 and C7 were then identified by one-bond correlations, or by

the couplings H10-C5, H10-C7, H5-C7. H4 was identified as coupling with H5, or by its

coupling with C6, the third carbon coupling with H10. One coupling of F8 or F9 with C1

was sufficient to identify these fluorines, since the pairs H8-F9 and F18-F19 are

revealed by selective decoupling in the 19F spectra. The assignments for the positions

11-20 was done in a similar way to the one for positions 1-10. The proton signals for

positions 21-27 can be assigned based on their intensity and multiplicity. The carbons in

these positions were assigned based on their one-bond and long-range couplings to

protons.

The 13C chemical shifts difference in positions 3/13and 6/16 as well as the 15N

chemical shifts difference between compounds 17 compared to 16, 18, 19 and 20

suggest that in 17 the nitrogen is more ‘amino-like’ while in 16, 18, 19 and 20 it is an

amido.

248

Figure A- 78. 1H NMR (C6D6, 300 MHz) spectrum of 16.

Figure A- 79. 19F{1H} NMR (C6D6, 300 MHz) spectrum of 16.

110314D

8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5


0

5

10

15

20

25

30

Norm

alized Inte

nsity

2.708.115.851.351.273.361.121.97

0.7

50.7

70.8

0

1.2

1

1.9

62.0

0

4.7

44.7

74.7

94.8

24.8

45.0

45.0

65.0

85.1

15.1

3

6.5

76.6

06.6

16.6

46.6

76.7

96.8

37.3

37.3

67.3

97.7

2

110314C

-70.5 -71.0 -71.5 -72.0 -72.5 -73.0 -73.5 -74.0 -74.5 -75.0 -75.5 -76.0 -76.5 -77.0 -77.5 -78.0


0

8

16

24

32

40

48

56

64

72

80

88

96

Norm

alized Inte

nsity

-77.2

3-7

7.2

0-7

7.1

7-7

7.1

4

-73.9

6-7

3.9

2-7

3.8

9

-71.5

7-7

1.5

3-7

1.4

9-7

1.4

6-7

1.2

1-7

1.1

7-7

1.1

4-7

1.1

1

249

Figure A- 80. 19F{1H} NMR (C6D6, 300 MHz) spectrum of 16 with selective decoupling at 73.9 ppm.

Figure A- 81. 13C{1H} NMR (C6D6, 300 MHz) spectrum of 16.

110421E

-70.5 -71.0 -71.5 -72.0 -72.5 -73.0 -73.5 -74.0 -74.5 -75.0 -75.5 -76.0 -76.5 -77.0 -77.5 -78.0


0

8

16

24

32

40

48

56

64

72

80

88

96

Norm

alized Inte

nsity

-77.2

3-7

7.1

9-7

7.1

6-7

7.1

3

-71.5

1

-71.2

0-7

1.1

7-7

1.1

4-7

1.1

1

110531E

260 240 220 200 180 160 140 120 100 80 60 40 20 0


0

8

16

24

32

40

48

56

64

72

80

Norm

alized Inte

nsity

20.7

820.9

621.4

3

29.8

433.6

3

90.2

7

124.2

6124.4

9124.6

9127.5

4131.7

2133.0

3134.5

7135.0

8145.8

1146.8

3

260.3

1

250

Figure A- 82. 1H-1H gDQFCOSY (C6D6, 500 MHz) spectrum of 16, expanded.

Figure A- 83. 1H-1H gDQFCOSY (C6D6, 500 MHz) spectrum of 16, full.

251

Figure A- 84. 1H-13C gHSQC (C6D6, 500 MHz) spectrum of 16, expanded.


252

Figure A- 86. 1H-13C gHMBC (C6D6, 500 MHz) spectrum of 16, full.


253



254


Figure A- 91. 19F-13C gHSQC (C6D6, 500 MHz) spectrum of 16, expanded.

255


Figure A- 93. 19F-13C gHMBC (C6D6, 500 MHz) spectrum of 16, expanded.

256



111109A

8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0


0

8

16

24

32

40

48

56

64

72

80

88

96

Norm

alized Inte

nsity

2.647.855.352.831.941.204.010.951.11

0.7

80.8

00.8

3

1.6

3

2.0

92.1

62.4

22.4

6

4.3

14.3

44.3

64.3

9

6.7

96.8

16.9

26.9

87.0

17.2

0

7.5

07.5

27.6

67.8

1

111109B

-64 -66 -68 -70 -72 -74 -76 -78 -80 -82 -84 -86 -88 -90


0

8

16

24

32

40

48

56

64

72

80

88

96

Norm

alized Inte

nsity

-76.4

0-7

6.3

8-7

6.3

4-7

6.3

2

-74.1

8-7

4.1

5-7

4.1

1-7

4.0

7

-71.2

6-7

1.2

3-7

1.2

0-7

1.1

6-69.4

4-6

9.4

0-69.3

8-6

9.3

4

257

Figure A- 96. 31P{1H} NMR (C6D6, 300 MHz) spectrum of 17.

Figure A- 97. 1H-13C gHSQC (C6D6, 500 MHz) spectrum of 17.

111109C

40 32 24 16 8 0 -8 -16 -24 -32 -40


0

8

16

24

32

40

48

56

64

72

80

88

96

Norm

alized Inte

nsity

21.7

6

258

Figure A- 98. 1H-13C gHMBC (C6D6, 500 MHz) spectrum of 17.


259



260



261



262

Figure A- 106. 19F-13C gHMBC (C6D6, 500 MHz) spectrum of 17, expanded.


263

Figure A- 108. 1H-1H gDQFCOSY (C6D6, 500 MHz) spectrum of 18.

Figure A- 109. 1H-1H gDQFCOSY (C6D6, 500 MHz) spectrum of 18, expanded.

264


Figure A- 111 1H-13C gHSQC (C6D6, 500 MHz) spectrum of 18, expanded.

265



266


Figure A- 115. 19F-19F gDQFCOSY (C6D6, 500 MHz) spectrum of 18.

267



268



269

Figure A- 120. 1H-1H gDQCOSY (C6D6, 500 MHz) spectrum of 19.

Figure A- 121. 1H-13C gHSQCAD (C6D6, 500 MHz) spectrum of 19, expanded.

270

Figure A- 122. 1H-13C gHSQCAD (C6D6, 500 MHz) spectrum of 19, expanded.

Figure A- 123. 1H-13C gHMBCAD (C6D6, 500 MHz) spectrum of 19.

271

Figure A- 124. 1H-13C gHMBCAD (C6D6, 500 MHz) spectrum of 19, expanded.


272


Figure A- 127. 1H-15N gHMBCAD (C6D6, 500 MHz) spectrum of 19, expanded.

273


Figure A- 129. 19F-19F gDQCOSY (C6D6, 500 MHz) spectrum of 19.

274

Figure A- 130. 19F-13C gHSQCAD (C6D6, 500 MHz) spectrum of 19, expanded.


275



110826AA

8.0 7.5 7.0 6.5 6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0


0

8

16

24

32

40

48

56

64

72

80

88

96

Norm

alized Inte

nsity

3.015.912.121.981.022.00

0.9

00.9

20.9

5

1.9

01.9

3

2.6

12.6

42.7

1

2.7

8

2.9

72.9

82.9

93.0

03.0

13.0

23.0

36.5

36.6

16.6

46.6

86.7

06.7

26.7

4

7.5

2

276

Figure A- 134. 19F NMR (C6D6, 300 MHz) spectrum of 20.

Figure A- 135. 13C{1H} NMR (C6D6, 300 MHz) spectrum of 20.

110826AB

-68 -69 -70 -71 -72 -73 -74 -75 -76 -77 -78 -79 -80


8

16

24

32

40

48

56

64

72

80

88

96

Norm

alized Inte

nsity

-76.4

2-7

6.3

9-7

6.3

6-7

6.3

3

-75.6

0-7

5.5

6-7

5.5

3-7

5.5

0

-71.8

1-7

1.7

8-7

1.7

5-7

1.7

2

-71.2

2-7

1.1

9-7

1.1

5-7

1.1

2

110826AC

150 140 130 120 110 100 90 80 70 60 50 40 30 20 10


0

5

10

15

20

25

Norm

alized Inte

nsity

19.2

620.7

420.9

9

26.9

3

82.2

982.7

383.1

6

119.6

5121.9

6122.9

5125.3

8127.4

8128.9

2132.8

0133.1

9133.8

6135.5

1

145.6

0146.4

5

277

Figure A- 136. 1H -13C gHMBC (C6D6, 500 MHz) spectrum of 20, expanded.


278



279

Figure A- 140. 1H -15N gHMBC (C6D6, 500 MHz) spectrum of 20.

Figure A- 141. 19F{1H} NMR (C6D6, 500 MHz) spectrum of 20 (bottom) and spectra with

selective homonuclear decoupling (top).

280

130321A_OMe_ligand

10 9 8 7 6 5 4 3 2 1 0


0

80

160

240

320

400

480

560

640

720

800

880

960N

orm

alized Inte

nsity

18.216.031.952.022.000.85

9.9

0 7.4

37.4

37.4

1

7.2

37.0

9 7.0

77.0

66.5

56.5

4

3.5

7

1.4

6


130321A_OMe_ligand_13C

160 150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0


0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

Norm

alized Inte

nsity

156.2

9

143.3

6

130.0

4 127.3

8

125.4

7123.7

7

108.1

4

60.7

9

35.2

0

31.0

3

Figure A- 143. 13C{1H} NMR (CDCl3, 500 MHz) spectrum of 22.

281

130424A_ONOB

8 7 6 5 4 3 2 1 0


0

200

400

600

800

1000

1200

1400N

orm

alized Inte

nsity

19.652.012.062.00

7.5

27.5

0

7.2

77.2

37.2

27.0

8 7.0

7 6.7

1

1.5

51.5

2


130424A_ONOB_13C

150 140 130 120 110 100 90 80 70 60 50 40 30 20 10 0


0

200

400

600

800

1000

1200

1400

1600

1800

2000

Norm

alized Inte

nsity

148.3

3

140.0

0

128.4

6 125.2

0123.4

3121.6

2120.5

0

106.9

1

35.2

2

29.9

6


282

A.2 IR Data

Figure A- 146. IR spectrum of 2 (thin film).


283


Figure A- 149. Infrared spectrum of 5 (thin film).

611

.1

669

.2

710

.2746

.1

778

.9806

.9843

.9869

.5

984

.6

104

1.9

110

6.4

122

1.5

124

1.6

126

3.9

132

3.6

135

7.7

140

4.1

146

9.3

155

1.7

158

3.9

286

7.8

290

4.0

295

6.0

*T ue Dec 07 15:36:40 2010 (GMT -05:00)

50

55

60

65

70

75

80

85

90

95

100

%T

1000 1500 2000 2500 3000

cm-1

284



613

.2648

.9

689

.4

719

.9747

.2

779

.7

862

.6

896

.5

976

.4996

.4

106

4.8

111

6.2

119

6.8

121

1.6

126

2.7

132

3.8

135

4.2

141

0.7

143

8.6

148

2.7

154

9.3

158

0.5

286

6.4

291

3.8

295

2.3

305

7.9

*W ed Jun 09 11:07:51 2010 (GMT -04:00)

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100

%T

1000 1500 2000 2500 3000

cm-1

465

.8496

.9530

.0

630

.5674

.6703

.9

748

.7

827

.4

965

.4

110

2.8

113

3.6

=116

9.2

120

0.9

125

9.5

140

1.1

150

4.3

159

2.5

162

3.3

176

3.2

184

6.5

191

6.0

287

6.3

292

9.4

298

1.4

303

5.6

331

5.8

**W ed May 25 12:43:57 2011 (GMT -04:00)

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100

%T

500 1000 1500 2000 2500 3000 3500 4000

cm-1

285



531

.9

573

.5

673

.4710

.0728

.5

747

.4763

.2

911

.1

962

.4977

.8100

4.2

113

0.5

114

6.3

118

0.3

121

8.9

125

7.7

136

9.5

140

6.1

145

6.8

149

2.1

175

9.4

184

2.8

190

6.4

287

2.6

293

3.0

298

1.3

*Fri Apr 22 16:55:42 2011 (GMT -04:00)

-20

-10

0

10

20

30

40

50

60

70

80

90

100

%T

1000 1500 2000 2500 3000 3500 4000

cm-1

743

.0

885

.8955

.3

966

.9111

7.4

116

7.5

121

7.71

267.

9

143

7.7

148

4.0

286

1.7

292

3.4

296

5.9

*W ed Nov 09 15:39:16 2011 (GMT -05:00)

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100

%T

1000 1500 2000 2500 3000 3500 4000

cm-1

286

A.3 UV-Vis Data

Figure A- 154. UV-vis spectra of 5 in toluene (1.79 and 8.94 x10-5 M)

Figure A- 155. UV-vis of 6 in THF (0.057 mM, red; 0.113 mM, blue).

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

250 450 650 850

AU

λ (nm)

0.057 mM [tBuOCO]CrO(CH2PPh3)

0.113 mM [tBuOCO]CrO(CH2PPh3)

287

A.4 MS Data

Figure A- 156. DART mass spectroscopy spectra of 18OPPh3.

Figure A- 157. ESI-TOF mass spectroscopy spectra of 8.

288

Figure A- 158. GC-CI mass spectroscopy spectra of 22.

Figure A- 159. ESI mass spectroscopy spectra of 23.

289

A.5 EPR Data

Figure A- 160. EPR spectrum of 3 (10 mM solution, toluene) at T = 298 K.

Figure A- 161. Procedure used to simulate the high frequency (240 GHz) powder EPR

spectrum at T = 4.5 K. Individually simulated spectra of an S = 2 (a) and an S = 1.5 (b) systems are added together to get the total spectrum (c) corresponding to the mixture of the dimer (4) and monomer (2).

290

Figure A- 162. Solution EPR of a mixture of 3 and 3a (5.0 x10-3 M) in toluene (blue) and a 3 and 3a solution (1.6 x10-3 M) in toluene (blue) with the addition of 6 equiv. MeCN (red).

A.6 CV Data

Figure A- 163. Cyclic voltammograms of 5 x10-3 M solution of 2, 4, and 5 in 0.1 M

TBAH/CH2Cl2 at 100 mVs-1; glassy carbon working and Ag/Ag+ reference electrodes.

3.53E+03 3.55E+03 3.57E+03 3.59E+03

toluene

acetonitrile

291

A.7 X-Ray Crystallographic Data

Figure A- 164. Molecular structure of 1. Hydrogen atoms are omitted for clarity.

X-ray experimental: Data were collected at 173 K on a Siemens SMART

PLATFORM equipped with A CCD area detector and a graphite monochromator

utilizing MoKα radiation ( = 0.71073 Å). Cell parameters were refined using up to 8192

reflections. A full sphere of data (1850 frames) was collected using the -scan method

(0.3° frame width). The first 50 frames were re-measured at the end of data collection

to monitor instrument and crystal stability (maximum correction on I was < 1 %).

Absorption corrections by integration were applied based on measured indexed crystal

faces. The structure was solved by the Direct Methods in SHELXTL6, and refined using

full-matrix least squares. The non-H atoms were treated anisotropically, whereas the

292

hydrogen atoms were calculated in ideal positions and were riding on their respective

carbon atoms. The coordinated THF molecule is disordered in three parts and was

refined as such with the site occupation factors dependently refined. All three THF

parts were constrained to maintain similar geometries. The largest electron density

peak, 1.57 e.Å-3, is within 0.92 A from K1 and could not be resolved as a disordered

site, thus it was attributed to its anisotropy. A total of 328 parameters were refined in

the final cycle of refinement using 4418 reflections with I > 2σ(I) to yield R1 and wR2 of

7.37% and 22.03%, respectively. Refinement was done using F2.

293

Table A- 3. Crystal data, structure solution and refinement for 1.

Item Value

identification code jf05

empirical formula C30H36K2O3

formula weight 522.79

T (K) 173(2)

λ (Å) 0.71073

crystal system Monoclinic

space group C2/c

a (Å) 18.3698(16)

b (Å) 18.2304(15)

c (Å) 16.6555(14)

α (deg) 90

β (deg) 94.661(2)

γ (deg) 90

V (Å3) 5559.3(8)

Z 8

ρcalcd (Mg mm-3

) 1.249

crystal size (mm3) 0.17 x 0.14 x 0.13

abs coeff (mm-1

) 0.369

F(000) 2224

θ range for data collection 1.58 to 27.50

limiting indices -23≤h≤23, -23≤k≤14, -20≤l≤21

no. of reflns collcd 18576

no. of ind reflns (Rint) 6361 (0.0591)

Completeness to θ = 27.50° 99.70%

absorption corr Integration

refinement method Full-matrix least-squares on F2

data / restraints / parameters 6361 / 61 / 328

R1,a wR2

b [I > 2σ ] 0.0737, 0.2203 [4418]

R1,a wR2

b (all data) 0.0977, 0.2376

GOFc on F

2 1.053

largest diff. peak and hole 1.569 and -0.662 e.Å-3

R1 = Σ (||Fo| - |Fc||) / Σ |Fo|

wR2 = [Σ [w(Fo2 - Fc

2)2] / Σ [w(Fo

2)2]]

1/2

S = [Σ[w(Fo2 - Fc

2)2] / (n-p)]

1/2

w= 1/[σ2(Fo

2)+(m*p)

2+n*p], p = [max(Fo

2,0)+ 2* Fc

2]/3, m & n are constants.

294

Table A- 4. Atomic coordinates ( x 104) and equivalent isotropic displacement parameters (Å2x 103) for 1. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor.

Atom X Y Z U(eq)

K2 1398(1) 1760(1) 9022(1) 53(1)

K1 1006(1) 3250(1) 7491(1) 44(1)

O1 195(1) 2538(1) 8596(2) 45(1)

O2 2154(1) 2743(1) 8328(1) 40(1)

C1 1178(2) 3756(2) 9188(2) 35(1)

C2 1781(2) 4132(2) 8928(2) 36(1)

C3 1647(2) 4804(2) 8529(2) 45(1)

C4 954(2) 5071(2) 8382(2) 51(1)

C5 356(2) 4680(2) 8632(2) 44(1)

C6 464(2) 4016(2) 9038(2) 36(1)

C7 -175(2) 3594(2) 9288(2) 37(1)

C8 -270(2) 2843(2) 9047(2) 36(1)

C9 -927(2) 2488(2) 9257(2) 40(1)

C10 -1404(2) 2870(3) 9701(3) 59(1)

C11 -1293(2) 3584(3) 9947(3) 73(1)

C12 -680(2) 3948(2) 9722(3) 57(1)

C13 2534(2) 3832(2) 9025(2) 37(1)

C14 2684(2) 3133(2) 8681(2) 36(1)

C15 3436(2) 2895(2) 8716(2) 42(1)

C16 3974(2) 3353(2) 9074(2) 46(1)

C17 3815(2) 4032(2) 9397(2) 48(1)

C18 3103(2) 4270(2) 9370(2) 44(1)

C19 -1092(2) 1690(2) 8988(2) 46(1)

C20 -1836(2) 1425(2) 9242(3) 59(1)

C21 -501(2) 1175(2) 9376(3) 69(1)

C22 -1123(2) 1600(2) 8072(2) 53(1)

C23 3646(2) 2177(2) 8302(2) 52(1)

C24 4459(2) 1991(3) 8469(3) 73(1)

C25 3215(2) 1522(2) 8557(3) 63(1)

C26 3490(2) 2280(3) 7384(2) 67(1)

O3 1461(12) 254(9) 8426(14) 65(1)

C27 1958(9) -72(11) 7895(13) 85(3)

C28 1404(13) -598(16) 7454(13) 140(5)

C29 705(10) -557(18) 7908(16) 159(7)

C30 947(14) -251(13) 8751(13) 99(3)

O3' 1408(7) 302(6) 8509(11) 65(1)

C27' 2058(7) -37(7) 8243(11) 85(3)

C28' 1844(9) -850(7) 8189(18) 140(5)

C29' 1065(9) -912(7) 8450(17) 159(7)

C30' 746(7) -133(8) 8438(13) 99(3)

O3" 1728(6) 285(5) 8611(7) 65(1)

C27" 2384(6) -153(7) 8775(10) 85(3)

C28" 2162(10) -840(11) 8277(18) 140(5)

C29" 1329(9) -771(14) 8063(17) 159(7)

C30" 1068(7) -158(9) 8609(15) 99(3)

295

Table A- 5. Bond lengths (in Å) for 1. Bond Length Bond Length

K2-O2 2.596(2)

K2-O1 2.673(3)

K2-O3' 2.792(10)

K2-O3" 2.852(10)

K2-O3 2.924(15)

K2-C17#1 3.057(4)

K2-C16#1 3.305(4)

K2-C18#1 3.338(3)

K2-C22#2 3.494(4)

K2-C14 3.520(3)

K2-K1 3.7543(11)

K2-H1 2.93(3)

K1-O2 2.601(2)

K1-O1 2.780(2)

K1-C8#2 2.895(3)

K1-C1 2.966(3)

K1-O1#2 3.029(3)

K1-C2 3.128(3)

K1-C6 3.162(3)

K1-C22#2 3.162(4)

K1-C9#2 3.218(3)

K1-C7#2 3.282(3)

K1-C3 3.474(3)

K1-C5 3.492(3)

O1-C8 1.307(4)

O1-K1#2 3.029(3)

O2-C14 1.306(4)

C1-C6 1.399(4)

C1-C2 1.400(4)

C1-H1 0.99(3)

C2-C3 1.405(5)

C2-C13 1.485(5)

C3-C4 1.366(5)

C4-C5 1.400(5)

C5-C6 1.393(5)

C6-C7 1.489(4)

C7-C12 1.382(5)

C7-C8 1.433(4)

C7-K1#2 3.282(3)

C8-C9 1.437(4)

C8-K1#2 2.895(3)

C9-C10 1.381(5)

C9-C19 1.544(5)

C9-K1#2 3.219(3)

C10-C11 1.374(6)

C11-C12 1.386(6)

C13-C18 1.401(4)

C13-C14 1.433(5)

C14-C15 1.445(5)

C15-C16 1.392(5)

C15-C23 1.542(5)

C16-C17 1.390(5)

C16-K2#1 3.305(4)

C17-C18 1.375(5)

C17-K2#1 3.057(4)

C18-K2#1 3.338(3)

C19-C22 1.531(5)

C19-C21 1.538(5)

C19-C20 1.541(5)

C22-K1#2 3.162(4)

C22-K2#2 3.494(4)

C23-C25 1.513(6)

C23-C24 1.535(5)

C23-C26 1.544(5)

O3-C27 1.449(5)

O3-C30 1.454(5)

C27-C28 1.541(5)

C28-C29 1.543(5)

C29-C30 1.543(5)

O3'-C27' 1.445(5)

O3'-C30' 1.449(5)

C27'-C28' 1.534(5)

C28'-C29' 1.533(5)

C29'-C30' 1.536(5)

O3"-C27" 1.454(5)

O3"-C30" 1.456(5)

C27"-C28" 1.538(5)

C28"-C29" 1.547(5)

C29"-C30" 1.542(5)

Symmetry transformations used to generate equivalent atoms:

Table A- 6. Bond angles (°) for 1. Bond Angle Bond Angle

O2-K2-O1 88.61(7)

O2-K2-O3' 120.3(3)

O1-K2-O3' 116.8(4)

O2-K2-O3" 114.4(2)

O1-K2-O3" 128.6(2)

O3'-K2-O3" 12.1(4)

O2-K2-O3 117.4(3)

O1-K2-O3 117.6(5)

O3'-K2-O3 2.9(6)

O3"-K2-O3 11.0(5)

O2-K2-C17#1 145.09(9)

O1-K2-C17#1 108.59(9)

O3'-K2-C17#1 79.5(4)

O3"-K2-C17#1 78.8(2)

O3-K2-C17#1 82.0(4)

O2-K2-C16#1 129.02(9)

O1-K2-C16#1 93.27(8)

O3'-K2-C16#1 104.0(4)

296

Table A- 6. Continued. Bond Angle Bond Angle

O3"-K2-C16#1 103.7(2)

O3-K2-C16#1 106.5(4)

C17#1-K2-C16#1 24.85(10)

O2-K2-C18#1 128.57(8)

O1-K2-C18#1 132.75(8)

O3'-K2-C18#1 72.6(4)

O3"-K2-C18#1 67.2(2)

O3-K2-C18#1 74.2(5)

C17#1-K2-C18#1 24.32(9)

C16#1-K2-C18#1 42.22(9)

O2-K2-C22#2 69.68(8)

O1-K2-C22#2 74.35(8)

O3'-K2-C22#2 67.7(4)

O3"-K2-C22#2 72.5(2)

O3-K2-C22#2 65.8(5)

C17#1-K2-C22#2 143.37(10)

C16#1-K2-C22#2 158.16(10)

C18#1-K2-C22#2 139.64(9)

O2-K2-C14 17.56(7)

O1-K2-C14 97.51(7)

O3'-K2-C14 127.3(2)

O3"-K2-C14 118.3(2)

O3-K2-C14 124.6(3)

C17#1-K2-C14 127.53(9)

C16#1-K2-C14 113.12(8)

C18#1-K2-C14 112.65(8)

C22#2-K2-C14 86.72(9)

O2-K2-K1 43.80(5)

O1-K2-K1 47.69(5)

O3'-K2-K1 119.1(4)

O3"-K2-K1 123.5(2)

O3-K2-K1 117.4(5)

C17#1-K2-K1 153.62(8)

C16#1-K2-K1 130.80(7)

C18#1-K2-K1 167.63(7)

C22#2-K2-K1 51.58(6)

C14-K2-K1 58.00(5)

O2-K2-H1 61.0(6)

O1-K2-H1 59.0(6)

O3'-K2-H1 175.7(7)

O3"-K2-H1 172.1(6)

O3-K2-H1 175.7(8)

C17#1-K2-H1 101.5(7)

C16#1-K2-H1 76.8(7)

C18#1-K2-H1 110.0(6)

C22#2-K2-H1 110.1(6)

C14-K2-H1 55.3(6)

K1-K2-H1 58.5(6)

O2-K1-O1 86.26(7)

O2-K1-C8#2 133.12(8)

O1-K1-C8#2 103.29(8)

O2-K1-C1 65.21(8)

O1-K1-C1 62.39(8)

C8#2-K1-C1 158.35(9)

O2-K1-O1#2 133.45(7)

O1-K1-O1#2 78.03(8)

C8#2-K1-O1#2 25.37(8)

C1-K1-O1#2 136.01(8)

O2-K1-C2 58.26(8)

O1-K1-C2 88.22(8)

C8#2-K1-C2 163.60(9)

C1-K1-C2 26.39(8)

O1#2-K1-C2 160.29(8)

O2-K1-C6 90.90(8)

O1-K1-C6 56.35(7)

C8#2-K1-C6 132.77(9)

C1-K1-C6 26.15(8)

O1#2-K1-C6 114.46(7)

C2-K1-C6 45.86(8)

O2-K1-C22#2 75.50(9)

O1-K1-C22#2 78.79(9)

C8#2-K1-C22#2 62.12(9)

C1-K1-C22#2 125.05(10)

O1#2-K1-C22#2 58.63(9)

C2-K1-C22#2 132.70(9)

C6-K1-C22#2 134.05(9)

O2-K1-C9#2 107.85(8)

O1-K1-C9#2 114.22(8)

C8#2-K1-C9#2 26.53(8)

C1-K1-C9#2 171.88(9)

O1#2-K1-C9#2 45.37(7)

C2-K1-C9#2 153.89(9)

C6-K1-C9#2 159.03(8)

C22#2-K1-C9#2 47.21(9)

O2-K1-C7#2 148.11(8)

O1-K1-C7#2 116.88(8)

C8#2-K1-C7#2 25.87(8)

C1-K1-C7#2 143.77(9)

O1#2-K1-C7#2 43.93(7)

C2-K1-C7#2 137.84(8)

C6-K1-C7#2 119.80(8)

C22#2-K1-C7#2 87.27(9)

C9#2-K1-C7#2 44.14(8)

O2-K1-C3 78.20(8)

O1-K1-C3 103.27(8)

C8#2-K1-C3 139.81(9)

C1-K1-C3 42.80(8)

O1#2-K1-C3 147.93(8)

C2-K1-C3 23.84(8)

C6-K1-C3 49.53(8)

C22#2-K1-C3 153.44(10)

C9#2-K1-C3 142.21(9)

C7#2-K1-C3 114.00(8)

O2-K1-C5 105.75(8)

O1-K1-C5 76.32(8)

C8#2-K1-C5 121.13(9)

297


C1-K1-C5 42.61(8)

O1#2-K1-C5 112.37(7)

C2-K1-C5 49.79(8)

C6-K1-C5 23.50(8)

C22#2-K1-C5 154.92(10)

C9#2-K1-C5 145.27(8)

C7#2-K1-C5 101.17(8)

C3-K1-C5 40.32(8)

C8-O1-K2 129.6(2)

C8-O1-K1 126.30(19)

K2-O1-K1 86.99(7)

C8-O1-K1#2 71.56(17)

K2-O1-K1#2 158.73(10)

K1-O1-K1#2 78.92(7)

C14-O2-K2 125.57(19)

C14-O2-K1 126.2(2)

K2-O2-K1 92.50(7)

C6-C1-C2 122.2(3)

C6-C1-K1 84.76(17)

C2-C1-K1 83.28(17)

C6-C1-H1 120.3(18)

C2-C1-H1 117.5(18)

K1-C1-H1 104.0(19)

C1-C2-C3 117.4(3)

C1-C2-C13 122.6(3)

C3-C2-C13 119.9(3)

C1-C2-K1 70.33(16)

C3-C2-K1 92.0(2)

C13-C2-K1 104.83(19)

C4-C3-C2 121.3(3)

C4-C3-K1 85.9(2)

C2-C3-K1 64.15(17)

C3-C4-C5 120.5(3)

C6-C5-C4 120.2(3)

C6-C5-K1 64.80(18)

C4-C5-K1 84.7(2)

C5-C6-C1 118.3(3)

C5-C6-C7 120.0(3)

C1-C6-C7 121.7(3)

C5-C6-K1 91.7(2)

C1-C6-K1 69.10(16)

C7-C6-K1 107.88(18)

C12-C7-C8 121.4(3)

C12-C7-C6 118.9(3)

C8-C7-C6 119.7(3)

C12-C7-K1#2 106.3(2)

C8-C7-K1#2 61.81(16)

C6-C7-K1#2 99.53(18)

O1-C8-C7 119.8(3)

O1-C8-C9 123.2(3)

C7-C8-C9 116.6(3)

O1-C8-K1#2 83.07(18)

C7-C8-K1#2 92.32(19)

C9-C8-K1#2 89.40(18)

C10-C9-C8 119.0(3)

C10-C9-C19 120.8(3)

C8-C9-C19 120.2(3)

C10-C9-K1#2 106.5(3)

C8-C9-K1#2 64.07(16)

C19-C9-K1#2 98.63(19)

C11-C10-C9 123.5(3)

C10-C11-C12 118.5(4)

C7-C12-C11 120.8(4)

C18-C13-C14 120.7(3)

C18-C13-C2 119.5(3)

C14-C13-C2 119.4(3)

O2-C14-C13 120.2(3)

O2-C14-C15 122.0(3)

C13-C14-C15 117.7(3)

O2-C14-K2 36.87(14)

C13-C14-K2 114.53(19)

C15-C14-K2 115.6(2)

O2-C14-K1 36.44(15)

C13-C14-K1 89.06(19)

C15-C14-K1 145.9(2)

K2-C14-K1 64.32(6)

C16-C15-C14 118.7(3)

C16-C15-C23 120.4(3)

C14-C15-C23 120.7(3)

C17-C16-C15 122.5(3)

C17-C16-K2#1 67.5(2)

C15-C16-K2#1 100.3(2)

C18-C17-C16 119.8(3)

C18-C17-K2#1 89.4(2)

C16-C17-K2#1 87.6(2)

C17-C18-C13 120.6(3)

C17-C18-K2#1 66.29(19)

C13-C18-K2#1 99.0(2)

C22-C19-C21 108.7(4)

C22-C19-C20 106.2(3)

C21-C19-C20 107.7(3)

C22-C19-C9 112.4(3)

C21-C19-C9 109.8(3)

C20-C19-C9 111.9(3)

C19-C22-K1#2 101.3(2)

C19-C22-K2#2 167.4(3)

K1#2-C22-K2#2 68.46(8)

C25-C23-C24 107.3(4)

C25-C23-C15 112.9(3)

C24-C23-C15 112.5(3)

C25-C23-C26 108.3(3)

C24-C23-C26 107.8(3)

C15-C23-C26 107.9(3)

C27-O3-C30 115.4(11)

C27-O3-K2 129.5(11)

C30-O3-K2 115.0(10)

298


O3-C27-C28 97.0(9)

C27-C28-C29 106.2(4)

C28-C29-C30 106.0(4)

O3-C30-C29 92.2(12)

C27'-O3'-C30' 116.7(8)

C27'-O3'-K2 121.8(8)

C30'-O3'-K2 121.3(7)

O3'-C27'-C28' 102.6(7)

C29'-C28'-C27' 107.2(4)

C28'-C29'-C30' 107.0(4)

O3'-C30'-C29' 100.8(8)

C27"-O3"-C30" 111.9(9)

C27"-O3"-K2 131.5(8)

C30"-O3"-K2 109.3(7)

O3"-C27"-C28" 99.5(7)

C27"-C28"-C29" 105.8(4)

C30"-C29"-C28" 105.8(4)

O3"-C30"-C29" 96.0(10)


Table A- 7. Anisotropic displacement parameters (Å2x 103) for 1. The anisotropic displacement factor exponent takes the form: -2a* b* U12 ]

U11 U22 U33 U23 U13 U12

K2 55(1) 41(1) 64(1) 13(1) 23(1) 4(1)

K1 49(1) 43(1) 38(1) -6(1) 1(1) -1(1)

O1 45(1) 32(1) 58(1) -6(1) 17(1) -6(1)

O2 38(1) 40(1) 43(1) -6(1) 5(1) -6(1)

C1 43(2) 32(2) 30(1) -4(1) 4(1) -5(1)

C2 45(2) 28(2) 34(2) -3(1) 3(1) -8(1)

C3 52(2) 35(2) 48(2) 5(1) 3(2) -13(1)

C4 63(2) 30(2) 59(2) 9(2) -4(2) -7(2)

C5 51(2) 33(2) 48(2) -2(1) -1(2) 1(1)

C6 44(2) 31(2) 34(2) -8(1) 5(1) -4(1)

C7 40(2) 36(2) 35(2) -5(1) 4(1) -4(1)

C8 39(2) 37(2) 31(1) 2(1) 4(1) -6(1)

C9 39(2) 43(2) 36(2) 6(1) 1(1) -9(1)

C10 44(2) 72(3) 64(2) -10(2) 17(2) -20(2)

C11 54(2) 81(3) 90(3) -38(3) 34(2) -13(2)

C12 52(2) 56(2) 65(2) -26(2) 19(2) -9(2)

C13 41(2) 37(2) 33(2) 5(1) 6(1) -10(1)

C14 38(2) 41(2) 30(1) 2(1) 8(1) -8(1)

C15 42(2) 54(2) 31(2) -1(1) 7(1) -5(2)

C16 35(2) 62(2) 41(2) 1(2) 3(1) -9(2)

C17 43(2) 54(2) 47(2) 5(2) -4(1) -17(2)

C18 51(2) 39(2) 43(2) 5(1) 1(1) -12(2)

C19 46(2) 39(2) 53(2) 13(2) -3(2) -12(1)

C20 49(2) 55(2) 71(3) 18(2) 0(2) -19(2)

C21 52(2) 49(2) 104(4) 29(2) -9(2) -9(2)

C22 69(2) 32(2) 58(2) -6(2) 5(2) -12(2)

C23 42(2) 69(3) 45(2) -13(2) 4(2) 7(2)

C24 47(2) 96(3) 74(3) -28(3) -1(2) 14(2)

C25 64(3) 53(2) 72(3) -13(2) 6(2) 6(2)

C26 59(2) 101(4) 41(2) -22(2) 9(2) 7(2)

299

Figure A- 165. Molecular structure of 2 with ellipsoids drawn at the 50% probability

level and two THF lattice solvent molecules are removed for clarity.



utilizing MoK radiation ( = 0.71073 Å). Cell parameters were refined using up to 8192


(0.3 frame width). The first 50 frames were re-measured at the end of data collection



faces.

The structure was solved by the Direct Methods in SHELXTL6, and refined using



carbon atoms. There are two thf solvent molecules in the asymmetric unit in, addition to

the Cr complex. Two of the three coordinated thf molecules have three of the C atoms

300

disordered and were refined in two parts with their site occupation factors adding up to

1.00. One solvent molecule is wholly disordered while the second has only two C

atoms disordered. They were treated in the same manner like the coordinated thf

molecules. A total of 484 parameters were refined in the final cycle of refinement using

6265 reflections with I > 2(I) to yield R1 and wR2 of 5.22% and 12.20%, respectively.

Refinement was done using F2. SHELXTL6 (2000). Bruker-AXS, Madison, Wisconsin,

USA.

Table A- 8. Crystal data and structure refinement for 2. Item Value

Identification code orei10

Empirical formula C46 H67 Cr O7

Formula weight 784.00

Temperature 100(2) K

Wavelength 0.71073 Å

Crystal system Monoclinic

Space group P2(1)/c

Unit cell dimensions a = 22.0077(19) Å = 90°.

b = 10.5772(9) Å = 91.428(1)°.

c = 18.0096(15) Å = 90°.

Volume 4191.0(6) Å3

Z 4

Density (calculated) 1.243Mg/m3

Absorption coefficient 0.322 mm-1

F(000) 1692

Crystal size 0.21 x 0.20 x 0.17 mm3

Theta range for data collection 0.93 to 25.00°.

Index ranges -26≤h≤25, -12≤k≤12, -17≤l≤21

Reflections collected 24248

Independent reflections 7343 [R(int) = 0.0310]

Completeness to theta = 27.50° 99.4 %

Absorption correction None

Max. and min. transmission 0.9457 and 0.9360

Refinement method Full-matrix least-squares on F2

Data / restraints / parameters 7343 / 0 / 484

Goodness-of-fit on F2 1.040

Final R indices [I>2sigma(I)] R1 = 0.0522, wR2 = 0.1220 [6265]

R indices (all data) R1 = 0.0619, wR2 = 0.1282

Largest diff. peak and hole 0.780 and -0.520 e.Å-3

R1 = (||Fo| - |Fc||) / |Fo|

wR2 = [w(Fo2 - Fc

2)2] / wFo22]]1/2

S = [w(Fo2 - Fc

2)2] / (n-p)]1/2

w= 1/[2(Fo2)+(m*p)

2+n*p], p = [max(Fo

2,0)+ 2* Fc2]/3, m & n are constants.

301


Atom X Y Z U(eq)

Cr1 2516(1) 4740(1) 2400(1) 12(1)

O1 3312(1) 3987(2) 2423(1) 15(1)

O2 1723(1) 5500(2) 2447(1) 15(1)

O3 2548(1) 4641(2) 3617(1) 19(1)

O4 2953(1) 6461(2) 2485(1) 17(1)

O5 2077(1) 3024(2) 2411(1) 18(1)

C1 2502(1) 4817(2) 1284(1) 14(1)

C2 2124(1) 5717(2) 906(1) 16(1)

C3 2119(1) 5745(3) 124(2) 21(1)

C4 2502(1) 4976(3) -273(2) 23(1)

C5 2883(1) 4129(3) 93(2) 21(1)

C6 2876(1) 4005(2) 870(1) 17(1)

C7 3515(1) 3117(2) 1957(1) 14(1)

C8 3286(1) 3025(2) 1215(2) 17(1)

C9 3459(1) 1982(3) 789(2) 21(1)

C10 3870(1) 1092(3) 1054(2) 22(1)

C11 4135(1) 1257(2) 1754(2) 20(1)

C12 3977(1) 2251(2) 2215(2) 16(1)

C13 4277(1) 2402(2) 2994(2) 17(1)

C14 4796(1) 1452(3) 3125(2) 23(1)

C15 3809(1) 2170(3) 3601(2) 20(1)

C16 4552(1) 3737(3) 3082(2) 22(1)

C17 1503(1) 6429(2) 2021(1) 13(1)

C18 1718(1) 6628(2) 1290(1) 16(1)

C19 1529(1) 7725(3) 912(2) 19(1)

C20 1119(1) 8559(3) 1202(2) 22(1)

C21 871(1) 8298(2) 1888(2) 18(1)

C22 1047(1) 7248(2) 2306(1) 15(1)

C23 760(1) 6994(2) 3063(1) 16(1)

C24 251(1) 7936(3) 3229(2) 23(1)

C25 1241(1) 7113(3) 3696(2) 23(1)

C26 476(1) 5659(3) 3061(2) 21(1)

C27 2089(1) 4048(3) 4065(2) 24(1)

C28 2140(1) 4652(3) 4834(2) 26(1)

C29 2653(1) 5627(3) 4770(2) 24(1)

C30 3010(1) 5150(3) 4118(2) 20(1)

C31 2727(1) 7654(2) 2780(2) 22(1)

C32 3190(3) 8612(6) 2678(5) 26(2)

C33 3703(3) 7988(7) 2335(6) 31(2)

C34 3537(4) 6656(8) 2140(5) 21(2)

C32' 3079(3) 8666(6) 2333(6) 33(2)

C33' 3612(3) 8046(6) 2046(6) 29(2)

C34' 3449(4) 6746(7) 1978(5) 18(2)

C35 2325(1) 1788(2) 2612(2) 22(1)

C36 1802(2) 875(5) 2597(4) 25(2)

C37 1271(3) 1617(6) 2314(5) 32(2)

C38 1551(3) 2780(6) 1916(4) 19(2)

C36' 1902(4) 850(8) 2230(7) 42(3)

C37' 1357(3) 1533(6) 1974(5) 18(2)

C38' 1455(4) 2896(8) 2104(6) 23(2)

O6 828(1) 2097(3) 140(2) 63(1)

302

Table A- 9. Continued. Atom X Y Z U(eq)

C39 295(2) 2050(4) -323(2) 59(1)

C40 415(4) 2872(8) -944(5) 64(2)

C41 899(3) 3757(7) -656(4) 47(2)

C40' 70(4) 3482(8) -448(5) 46(2)

C41' 611(5) 4218(10) -112(6) 65(3)

C42 1059(2) 3330(4) 61(3) 62(1)

O7 4042(3) 8255(7) -200(6) 45(2)

C43 3955(5) 6900(9) 110(6) 28(3)

C44 4201(5) 6263(10) -580(7) 45(3)

C45 4729(6) 7058(13) -783(9) 59(4)

C46 4603(5) 8222(11) -579(8) 43(3)

O7' 4139(2) 8102(5) 128(4) 48(2)

C43' 3832(4) 6983(7) -103(5) 47(2)

C44' 4342(3) 6062(6) -233(4) 39(2)

C45' 4853(3) 6852(6) -518(4) 34(2)

C46' 4676(3) 8211(6) -305(5) 38(2)

Table A- 10. Bond lengths [Å] for 2. Bond Length Bond Length

Cr1-O1 1.9227(17)

Cr1-O2 1.9248(17)

Cr1-C1 2.011(3)

Cr1-O5 2.0566(18)

Cr1-O4 2.0624(18)

Cr1-O3 2.1938(18)

O1-C7 1.331(3)

O2-C17 1.331(3)

O3-C30 1.446(3)

O3-C27 1.449(3)

O4-C34 1.458(8)

O4-C31 1.461(3)

O4-C34' 1.472(7)

O5-C35 1.459(3)

O5-C38 1.466(6)

O5-C38' 1.469(8)

C1-C6 1.414(4)

C1-C2 1.426(4)

C2-C3 1.408(4)

C2-C18 1.494(4)

C3-C4 1.384(4)

C4-C5 1.383(4)

C5-C6 1.406(4)

C6-C8 1.499(4)

C7-C8 1.419(4)

C7-C12 1.436(4)

C8-C9 1.402(4)

C9-C10 1.381(4)

C10-C11 1.388(4)

C11-C12 1.389(4)

C12-C13 1.544(4)

C13-C14 1.536(4)

C13-C15 1.541(4)

C13-C16 1.542(4)

C17-C18 1.426(4)

C17-C22 1.431(4)

C18-C19 1.402(4)

C19-C20 1.375(4)

C21-C22 1.391(4)

C22-C23 1.541(4)

C23-C24 1.533(4)

C23-C25 1.541(4)

C23-C26 1.544(4)

C27-C28 1.527(4)

C28-C29 1.535(4)

C29-C30 1.514(4)

C31-C32 1.451(7)

C31-C32' 1.557(8)

C32-C33 1.458(9)

C33-C34 1.495(10)

C32'-C33' 1.450(9)

C33'-C34' 1.426(10)

C35-C36 1.501(6)

C35-C36' 1.514(9)

C36-C37 1.486(8)

C37-C38 1.558(9)

C36'-C37' 1.464(10)

C37'-C38' 1.475(11)

O6-C42 1.409(5)

O6-C39 1.422(5)

C39-C40 1.447(9)

C39-C40' 1.607(10)

C40-C41 1.501(10)

C41-C42 1.405(8)

C40'-C41' 1.535(13)

C41'-C42 1.391(11)

O7-C46 1.425(13)

O7-C43 1.552(13)

303


Bond Length Bond Length

C43-C44 1.527(15)

C44-C45 1.488(16)

C45-C46 1.316(17)

O7'-C43' 1.420(9)

O7'-C46' 1.436(8)

C43'-C44' 1.509(10)

C44'-C45' 1.501(8)

C45'-C46' 1.541(9)


Table A- 11. Bond angles [°] for 2. Bond Angle Bond Angle

O1-Cr1-O2 176.20(8)

O1-Cr1-C1 91.70(9)

O2-Cr1-C1 92.08(9)

O1-Cr1-O5 93.57(7)

O2-Cr1-O5 86.62(7)

C1-Cr1-O5 92.88(9)

O1-Cr1-O4 86.67(7)

O2-Cr1-O4 92.82(7)

C1-Cr1-O4 91.96(9)

O5-Cr1-O4 175.14(7)

O1-Cr1-O3 87.27(7)

O2-Cr1-O3 88.95(7)

C1-Cr1-O3 178.98(9)

O5-Cr1-O3 87.19(7)

O4-Cr1-O3 87.97(7)

C7-O1-Cr1 126.42(16)

C17-O2-Cr1 126.86(16)

C30-O3-C27 107.6(2)

C30-O3-Cr1 127.58(16)

C27-O3-Cr1 124.85(16)

C34-O4-C31 110.2(3)

C34-O4-C34' 14.1(4)

C31-O4-C34' 108.2(3)

C34-O4-Cr1 120.5(3)

C31-O4-Cr1 128.87(16)

C34'-O4-Cr1 119.0(3)

C35-O5-C38 106.1(3)

C35-O5-C38' 110.5(3)

C38-O5-C38' 16.5(4)

C35-O5-Cr1 128.35(15)

C38-O5-Cr1 120.9(2)

C38'-O5-Cr1 120.8(3)

C6-C1-C2 119.6(2)

C6-C1-Cr1 120.50(19)

C2-C1-Cr1 119.88(19)

C3-C2-C1 118.7(2)

C3-C2-C18 117.3(2)

C1-C2-C18 123.9(2)

C4-C3-C2 121.0(3)

C5-C4-C3 120.2(3)

C4-C5-C6 120.9(3)

C5-C6-C1 119.3(2)

C5-C6-C8 117.1(2)

C1-C6-C8 123.6(2)

O1-C7-C8 121.5(2)

O1-C7-C12 118.9(2)

C8-C7-C12 119.6(2)

C9-C8-C7 118.2(2)

C9-C8-C6 119.1(2)

C7-C8-C6 122.7(2)

C10-C9-C8 122.2(3)

C9-C10-C11 119.0(3)

C10-C11-C12 122.1(3)

C11-C12-C7 118.4(2)

C11-C12-C13 120.8(2)

C7-C12-C13 120.7(2)

C14-C13-C15 107.1(2)

C14-C13-C16 107.2(2)

C15-C13-C16 109.9(2)

C14-C13-C12 111.9(2)

C15-C13-C12 110.5(2)

C16-C13-C12 110.2(2)

O2-C17-C18 121.2(2)

O2-C17-C22 119.3(2)

C18-C17-C22 119.6(2)

C19-C18-C17 118.0(2)

C19-C18-C2 118.8(2)

C17-C18-C2 123.2(2)

C20-C19-C18 122.4(3)

C19-C20-C21 119.1(2)

C20-C21-C22 122.0(2)

C21-C22-C17 118.5(2)

C21-C22-C23 120.2(2)

C17-C22-C23 121.2(2)

C24-C23-C22 112.1(2)

C24-C23-C25 107.1(2)

C22-C23-C25 110.6(2)

C24-C23-C26 107.3(2)

C22-C23-C26 109.4(2)

C25-C23-C26 110.3(2)

O3-C27-C28 106.7(2)

C27-C28-C29 104.5(2)

C30-C29-C28 103.4(2)

O3-C30-C29 103.8(2)

C32-C31-O4 108.1(3)

C32-C31-C32' 25.2(3)

O4-C31-C32' 103.2(3)

C31-C32-C33 106.9(5)

C32-C33-C34 109.9(6)

O4-C34-C33 104.2(5)

304


Bond Angle Bond Angle

C33'-C32'-C31 106.9(5)

C34'-C33'-C32' 105.2(6)

C33'-C34'-O4 109.5(5)

O5-C35-C36 106.9(3)

O5-C35-C36' 104.6(4)

C36-C35-C36' 26.9(4)

C37-C36-C35 105.2(4)

C36-C37-C38 105.0(5)

O5-C38-C37 100.0(4)

C37'-C36'-C35 108.0(6)

C36'-C37'-C38' 108.5(6)

O5-C38'-C37' 106.3(6)

C42-O6-C39 105.6(3)

O6-C39-C40 105.5(5)

O6-C39-C40' 107.2(4)

C40-C39-C40' 52.2(5)

C39-C40-C41 104.4(6)

C42-C41-C40 106.1(6)

C41'-C40'-C39 100.9(7)

C42-C41'-C40' 106.5(8)

C41'-C42-C41 54.3(5)

C41'-C42-O6 113.1(6)

C41-C42-O6 107.8(4)

C46-O7-C43 105.4(7)

C44-C43-O7 93.7(9)

C45-C44-C43 104.2(9)

C46-C45-C44 106.7(11)

C45-C46-O7 110.4(10)

C43'-O7'-C46' 107.5(5)

O7'-C43'-C44' 103.5(6)

C45'-C44'-C43' 105.1(5)

C44'-C45'-C46' 103.7(5)

O7'-C46'-C45' 106.1(5)


Table A- 12. Anisotropic displacement parameters (Å2x 103) for 2. The anisotropic

displacement factor exponent takes the form: -22[ h2 a*2U11 + ... + 2 h k a* b* U12 ]

U11 U22 U33 U23 U13 U12

Cr1 13(1) 10(1) 12(1) 0(1) 1(1) 1(1)

O1 14(1) 15(1) 15(1) -3(1) 1(1) 3(1)

O2 15(1) 14(1) 15(1) 2(1) 1(1) 3(1)

O3 18(1) 27(1) 13(1) 2(1) 1(1) -1(1)

O4 17(1) 13(1) 20(1) -2(1) 4(1) 0(1)

O5 16(1) 13(1) 23(1) 1(1) -3(1) -1(1)

C1 14(1) 15(1) 14(1) -1(1) 1(1) -4(1)

C2 14(1) 17(1) 15(1) 1(1) 0(1) -3(1)

C3 22(1) 22(1) 18(1) 3(1) -2(1) 0(1)

C4 31(2) 28(2) 11(1) 1(1) 0(1) -1(1)

C5 23(1) 23(1) 17(1) -5(1) 3(1) -1(1)

C6 16(1) 18(1) 17(1) -1(1) 0(1) -3(1)

C7 12(1) 11(1) 21(1) -2(1) 5(1) -2(1)

C8 15(1) 17(1) 20(1) -2(1) 4(1) -2(1)

C9 21(1) 22(1) 20(1) -5(1) 2(1) -2(1)

C10 24(2) 16(1) 28(2) -8(1) 7(1) 1(1)

C11 16(1) 15(1) 28(2) 2(1) 4(1) 2(1)

C12 13(1) 13(1) 22(1) 2(1) 5(1) -2(1)

C13 15(1) 16(1) 19(1) 2(1) 2(1) 2(1)

C14 20(1) 25(2) 25(2) 1(1) 0(1) 5(1)

C15 19(1) 21(1) 20(1) 1(1) 2(1) 2(1)

C16 19(1) 20(1) 26(2) 2(1) -3(1) -2(1)

C17 12(1) 12(1) 15(1) 1(1) -3(1) -3(1)

C18 13(1) 17(1) 18(1) 2(1) -2(1) -3(1)

C19 19(1) 21(1) 18(1) 5(1) 0(1) -2(1)

C20 22(1) 18(1) 28(2) 8(1) -1(1) 2(1)

C21 15(1) 16(1) 25(2) -2(1) 0(1) 2(1)

C22 12(1) 15(1) 17(1) 0(1) -3(1) -3(1)

C23 14(1) 17(1) 16(1) -2(1) 2(1) 1(1)

305

Table A- 12. Continued. U11 U22 U33 U23 U13 U12

C24 22(1) 23(2) 24(2) 1(1) 4(1) 5(1)

C25 23(2) 29(2) 18(1) -2(1) 0(1) 4(1)

C26 19(1) 20(1) 26(2) 3(1) 6(1) -1(1)

C27 31(2) 22(2) 20(2) 2(1) 9(1) -2(1)

C28 27(2) 32(2) 19(2) -2(1) 7(1) 3(1)

C29 28(2) 27(2) 17(1) -4(1) 1(1) 4(1)

C30 19(1) 24(1) 17(1) 0(1) -1(1) 3(1)

C31 21(1) 14(1) 32(2) -7(1) -4(1) 4(1)

C35 21(1) 12(1) 34(2) 4(1) 2(1) 3(1)

O6 51(2) 48(2) 90(2) 7(2) -18(2) -5(1)

C39 55(3) 68(3) 53(3) -19(2) -2(2) -17(2)

C42 54(3) 46(2) 85(3) 13(2) -24(2) -14(2)

306

Figure A- 166. X-ray structure of 3 with ellipsoids drawn at the 50% probability level.








faces.




carbon atoms. A total of 316 parameters were refined in the final cycle of refinement

307

using 3691 reflections with I > 2(I) to yield R1 and wR2 of 4.08% and 8.66%,

respectively. Refinement was done using F2.

SHELXTL6 (2000). Bruker-AXS, Madison, Wisconsin, USA.



Empirical formula C30H35CrO4





Space group P2(1)/n


b = 11.774(3) Å = 92.553(4)°.

c = 24.758(6) Å = 90°.

Volume 2575.8(10) Å3

Z 4

Density (calculated) 1.319 Mg/m3


F(000) 1084



Index ranges -10≤h≤10, -14≤k≤14, -30≤l≤29












R1 = (||Fo| - |Fc||) / |Fo|

wR2 = [w(Fo2 - Fc

2)2] / wFo22]]1/2

S = [w(Fo2 - Fc

2)2] / (n-p)]1/2

w= 1/[2(Fo2)+(m*p)

2+n*p], p = [max(Fo


308


Atom X Y Z U(eq)

Cr1 5610(1) 919(1) 1734(1) 12(1)

O1 6541(2) 1165(1) 2389(1) 14(1)

O2 5782(2) 1771(1) 1128(1) 14(1)

O3 7813(2) 260(1) 1529(1) 16(1)

O4 4739(2) -234(1) 1656(1) 19(1)

C1 3881(3) 1897(2) 1955(1) 13(1)

C2 2999(3) 2477(2) 1554(1) 14(1)

C3 1880(3) 3232(2) 1720(1) 18(1)

C4 1628(3) 3397(2) 2258(1) 19(1)

C5 2474(3) 2817(2) 2649(1) 16(1)

C6 3595(3) 2041(2) 2506(1) 13(1)

C7 5951(3) 1093(2) 2888(1) 13(1)

C8 4459(3) 1450(2) 2951(1) 13(1)

C9 3821(3) 1275(2) 3454(1) 16(1)

C10 4671(3) 815(2) 3881(1) 17(1)

C11 6175(3) 532(2) 3817(1) 16(1)

C12 6866(3) 654(2) 3326(1) 14(1)

C13 8520(3) 322(2) 3259(1) 17(1)

C14 8598(3) -664(2) 2852(1) 24(1)

C15 9416(3) 1359(2) 3061(1) 22(1)

C16 9304(3) -77(2) 3789(1) 22(1)

C17 4651(3) 2096(2) 772(1) 13(1)

C18 3229(3) 2377(2) 966(1) 14(1)

C19 2049(3) 2629(2) 588(1) 17(1)

C20 2295(3) 2669(2) 46(1) 20(1)

C21 3736(3) 2467(2) -136(1) 17(1)

C22 4949(3) 2173(2) 213(1) 14(1)

C23 6533(3) 1961(2) 2(1) 16(1)

C24 6552(3) 2114(2) -614(1) 22(1)

C25 7659(3) 2823(2) 254(1) 20(1)

C26 7061(3) 738(2) 124(1) 21(1)

C27 8048(3) -912(2) 1358(1) 20(1)

C28 9611(3) -933(2) 1137(1) 28(1)

C29 10438(3) -1(2) 1460(1) 29(1)

C30 9226(3) 893(2) 1506(1) 21(1)

Table A- 15. Bond length [Å] for 3. Bond Length Bond Length

Cr1-O4 1.5683(18)

Cr1-O1 1.8098(17)

Cr1-O2 1.8166(17)

Cr1-C1 2.009(2)

Cr1-O3 2.1781(17)

O1-C7 1.364(3)

O2-C17 1.359(3)

O3-C30 1.459(3)

O3-C27 1.461(3)

C1-C6 1.410(3)

C1-C2 1.411(4)

C2-C3 1.405(3)

C2-C18 1.483(3)

C3-C4 1.376(4)

C4-C5 1.378(4)

C5-C6 1.405(3)

C6-C8 1.485(3)

C7-C8 1.401(3)

C7-C12 1.421(3)

C8-C9 1.405(3)

C9-C10 1.381(4)

C10-C11 1.387(4)

C11-C12 1.393(3)

C12-C13 1.530(3)

309

Table A- 15. Continued. Bond Length Bond Length

C13-C16 1.532(4)

C13-C14 1.541(4)

C13-C15 1.548(4)

C17-C18 1.406(3)

C17-C22 1.424(3)

C18-C19 1.403(3)

C19-C20 1.371(4)

C20-C21 1.391(4)

C21-C22 1.391(4)

C22-C23 1.538(3)

C23-C25 1.535(4)

C23-C24 1.535(3)

C23-C26 1.540(4)

C27-C28 1.510(4)

C28-C29 1.526(4)

C29-C30 1.510(4)


Table A- 16. Bond angles [°] for 3. Bond Angles Bond Angles

O4-Cr1-O1 116.73(9)

O4-Cr1-O2 115.82(9)

O1-Cr1-O2 126.89(8)

O4-Cr1-C1 98.84(9)

O1-Cr1-C1 89.21(9)

O2-Cr1-C1 90.06(9)

O4-Cr1-O3 95.88(8)

O1-Cr1-O3 83.67(7)

O2-Cr1-O3 84.00(7)

C1-Cr1-O3 165.27(8)

C7-O1-Cr1 128.63(15)

C17-O2-Cr1 127.20(15)

C30-O3-C27 109.76(18)

C30-O3-Cr1 127.16(14)

C27-O3-Cr1 122.98(14)

C6-C1-C2 120.3(2)

C6-C1-Cr1 120.27(19)

C2-C1-Cr1 119.37(17)

C3-C2-C1 118.5(2)

C3-C2-C18 117.7(2)

C1-C2-C18 123.7(2)

C4-C3-C2 121.2(2)

C3-C4-C5 120.3(2)

C4-C5-C6 120.9(2)

C5-C6-C1 118.8(2)

C5-C6-C8 117.6(2)

C1-C6-C8 123.6(2)

O1-C7-C8 118.8(2)

O1-C7-C12 119.0(2)

C8-C7-C12 122.1(2)

C7-C8-C9 118.2(2)

C7-C8-C6 121.0(2)

C9-C8-C6 120.8(2)

C10-C9-C8 120.7(2)

C9-C10-C11 120.0(2)

C10-C11-C12 122.3(2)

C11-C12-C7 116.6(2)

C11-C12-C13 121.8(2)

C7-C12-C13 121.7(2)

C12-C13-C16 112.6(2)

C12-C13-C14 109.5(2)

C16-C13-C14 107.3(2)

C12-C13-C15 109.8(2)

C16-C13-C15 107.2(2)

C14-C13-C15 110.4(2)

O2-C17-C18 119.2(2)

O2-C17-C22 119.1(2)

C18-C17-C22 121.6(2)

C19-C18-C17 118.1(2)

C19-C18-C2 120.5(2)

C17-C18-C2 121.2(2)

C20-C19-C18 121.0(2)

C19-C20-C21 119.9(2)

C20-C21-C22 122.3(2)

C21-C22-C17 116.7(2)

C21-C22-C23 121.3(2)

C17-C22-C23 122.0(2)

C25-C23-C24 106.9(2)

C25-C23-C22 109.8(2)

C24-C23-C22 111.6(2)

C25-C23-C26 110.7(2)

C24-C23-C26 106.8(2)

C22-C23-C26 111.0(2)

O3-C27-C28 105.4(2)

C27-C28-C29 102.9(2)

C30-C29-C28 102.4(2)

O3-C30-C29 105.0(2)


310



U11 U22 U33 U23 U13 U12

Cr1 12(1) 14(1) 11(1) 0(1) 1(1) 0(1)

O1 12(1) 20(1) 11(1) 0(1) 0(1) 2(1)

O2 11(1) 19(1) 12(1) 3(1) -1(1) 1(1)

O3 14(1) 15(1) 19(1) -1(1) 3(1) 3(1)

O4 21(1) 16(1) 20(1) -2(1) 3(1) -1(1)

C1 11(1) 11(1) 16(1) -2(1) 2(1) -4(1)

C2 11(1) 15(1) 15(1) 0(1) 1(1) -2(1)

C3 17(1) 17(1) 20(1) 4(1) 0(1) 4(1)

C4 15(1) 19(1) 22(1) -1(1) 4(1) 2(1)

C5 17(1) 16(1) 15(1) -2(1) 4(1) -1(1)

C6 11(1) 13(1) 16(1) 0(1) 1(1) -3(1)

C7 17(1) 10(1) 11(1) -2(1) 1(1) -2(1)

C8 15(1) 11(1) 13(1) -3(1) 0(1) -3(1)

C9 17(1) 15(1) 16(1) -4(1) 1(1) -2(1)

C10 21(1) 17(1) 13(1) -1(1) 4(1) -4(1)

C11 23(2) 13(1) 12(1) -1(1) -6(1) 0(1)

C12 16(1) 11(1) 15(1) -1(1) -3(1) 0(1)

C13 17(1) 19(1) 14(1) 1(1) -1(1) 2(1)

C14 25(2) 26(2) 20(1) -2(1) 0(1) 9(1)

C15 15(1) 28(2) 23(2) 4(1) -1(1) -1(1)

C16 21(2) 25(2) 20(1) 2(1) -2(1) 6(1)

C17 13(1) 10(1) 16(1) 1(1) -2(1) -2(1)

C18 14(1) 12(1) 16(1) 2(1) 0(1) -1(1)

C19 11(1) 22(1) 19(1) 3(1) 1(1) 0(1)

C20 16(1) 26(2) 17(1) 5(1) -6(1) 0(1)

C21 19(1) 20(1) 13(1) 2(1) 0(1) -2(1)

C22 16(1) 12(1) 14(1) 0(1) -1(1) -2(1)

C23 15(1) 20(1) 12(1) 2(1) 2(1) 1(1)

C24 20(2) 30(2) 16(1) 0(1) 4(1) 4(1)

C25 13(1) 27(2) 20(1) 1(1) 2(1) -2(1)

C26 21(2) 24(2) 19(1) 1(1) 5(1) 6(1)

C27 24(2) 15(1) 21(1) -3(1) 3(1) 3(1)

C28 28(2) 22(1) 34(2) 1(1) 9(1) 9(1)

C29 17(2) 33(2) 36(2) 7(1) 5(1) 4(1)

C30 17(1) 22(1) 24(1) -1(1) 4(1) -3(1)

311

Figure A- 167. Molecular structure of 4 with ellipsoids drawn at the 50% probability

level and hydrogen atoms and an ether lattice molecule removed for clarity.








faces.




carbon atoms. The molecules are located on 2-fold rotation axes, thus only half a

312

molecule is in the asymmetric unit. There is also a disordered diethyl ether molecule in

the asymmetric unit. The solvent molecule was refined in two parts with their site

occupation factors dependently refined. A total of 353 parameters were refined in the

final cycle of refinement using 5027 reflections with I > 2(I) to yield R1 and wR2 of

5.18% and 12.27%, respectively. Refinement was done using F2.


Table A- 18. X-ray crystallographic structure parameters and refinement data for 4.

Item Value

empirical formula C68H90Cr2O9

formula weight 1155.4

crystal system Monoclinic

space group I2/a

crystal dimensions (mm) 0.23 × 0.18 × 0.14

a (Å) 24.7961(16)

b (Å) 11.9905(8)

c (Å) 21.8533(14)

β (deg) 104.6550(10)

volume (Å3) 6286.0(7)

Z (Å) 4

absorption coeff (mm–1

) 0.400

F (000) 2472

Dcalcd (g/cm3) 1.221

γ (Mo Kα) (Å) 0.71073

Temperature (K) 173(2)

θ range (deg) 1.70 to 27.50

completeness to θmax 99.70%

index ranges -32≤h≤25, -15≤k≤15, -20≤l≤28

reflections collected 20039

indep reflections [Rint] 7215 [0.0525]

data/restraints/param 7215/7/353

final R1 indices [I > R1 = 0.0518, wR2

2σ(I)] = 0.1227 [5027]


largest diff peak/hole e.Å–3

0.499/-0.339

goodness of fit on F2 0.989

313

Table A- 19. Atomic coordinates (x 104) and equivalent isotropic displacement

parameters (Å2x 103) for 4. U(eq) is defined as one third of the trace of the

orthogonalized Uij tensor. Atom X Y Z U(eq)

Cr1 1792(1) 605(1) 4671(1) 20(1)

O1 1408(1) 1462(1) 5087(1) 27(1)

O2 1490(1) -270(1) 3995(1) 23(1)

O3 2500 336(2) 5000 26(1)

O4 1574(1) -784(1) 5244(1) 29(1)

C1 1866(1) 1872(2) 4114(1) 23(1)

C2 1939(1) 1647(2) 3502(1) 25(1)

C3 1974(1) 2540(2) 3102(1) 32(1)

C4 1931(1) 3623(2) 3290(1) 39(1)

C5 1851(1) 3849(2) 3876(1) 36(1)

C6 1822(1) 2986(2) 4302(1) 27(1)

C7 1709(1) 3309(2) 4914(1) 30(1)

C8 1809(1) 4393(2) 5147(1) 40(1)

C9 1663(1) 4720(2) 5687(1) 48(1)

C10 1392(1) 3986(2) 5992(1) 42(1)

C11 1280(1) 2896(2) 5793(1) 33(1)

C12 1468(1) 2552(2) 5258(1) 28(1)

C13 961(1) 2089(2) 6128(1) 37(1)

C14 777(1) 2670(3) 6671(1) 51(1)

C15 1337(1) 1107(3) 6414(1) 43(1)

C16 430(1) 1681(3) 5652(1) 43(1)

C17 1944(1) 502(2) 3247(1) 23(1)

C18 2185(1) 295(2) 2742(1) 31(1)

C19 2162(1) -738(2) 2471(1) 35(1)

C20 1881(1) -1603(2) 2680(1) 33(1)

C21 1632(1) -1464(2) 3181(1) 25(1)

C22 1684(1) -401(2) 3474(1) 22(1)

C23 1315(1) -2428(2) 3395(1) 29(1)

C24 1271(1) -3448(2) 2955(1) 41(1)

C25 1620(1) -2797(2) 4065(1) 37(1)

C26 715(1) -2066(2) 3365(1) 37(1)

C27 1004(1) -1174(2) 5176(1) 38(1)

C28 1053(1) -2210(3) 5566(2) 54(1)

C29 1574(1) -2001(3) 6085(1) 54(1)

C30 1946(1) -1385(2) 5749(1) 40(1)

C31 168(3) 1108(6) 3496(4) 82(2)

C32 316(6) 2236(10) 3489(9) 151(7)

O5 -138(2) 2876(3) 3432(2) 70(2)

C33 -91(5) 4074(7) 3484(5) 129(4)

C34 182(5) 4481(9) 4097(5) 121(4)

C31' 272(4) 1210(8) 3148(5) 73(3)

C32' 336(5) 2310(8) 3443(7) 50(4)

O5' 175(3) 2977(6) 3877(4) 88(3)

C33' 273(7) 4129(11) 3797(8) 121(6)

C34' 170(7) 4657(13) 4400(8) 119(6)

314


Cr1-O3 1.7497(5)

Cr1-O1 1.7962(15)

Cr1-O2 1.8129(15)

Cr1-C1 1.983(2)

Cr1-O4 2.2308(16)

O1-C12 1.357(3)

O2-C22 1.353(3)

O3-Cr1#1 1.7496(5)

O4-C30 1.440(3)

O4-C27 1.460(3)

C1-C6 1.411(3)

C1-C2 1.419(3)

C2-C3 1.400(3)

C2-C17 1.483(3)

C3-C4 1.374(4)

C4-C5 1.372(4)

C5-C6 1.406(3)

C6-C7 1.486(3)

C7-C8 1.395(3)

C7-C12 1.406(3)

C8-C9 1.376(4)

C9-C10 1.377(4)

C10-C11 1.384(4)

C11-C12 1.425(3)

C11-C13 1.546(4)

C13-C15 1.534(4)

C13-C16 1.536(4)

C13-C14 1.540(3)

C17-C18 1.405(3)

C17-C22 1.412(3)

C18-C19 1.367(3)

C19-C20 1.389(3)

C20-C21 1.397(3)

C21-C22 1.418(3)

C21-C23 1.535(3)

C23-C25 1.534(3)

C23-C26 1.536(3)

C23-C24 1.543(3)

C27-C28 1.494(4)

C28-C29 1.509(4)

C29-C30 1.509(4)

C31-C32 1.403(11)

C32-O5 1.342(12)

O5-C33 1.443(9)

C33-C34 1.425(12)

C31'-C32' 1.459(11)

C32'-O5' 1.375(11)

O5'-C33' 1.421(12)

C33'-C34' 1.540(16)


Table A- 21. Bond angles [°] for 4. Bond Angles Bond Angles

O4-Cr1-O1 116.73(9)

O3-Cr1-O1 120.18(7)

O3-Cr1-O2 113.13(7)

O1-Cr1-O2 125.50(7)

O3-Cr1-C1 98.90(8)

O1-Cr1-C1 90.92(8)

O2-Cr1-C1 91.51(8)

O3-Cr1-O4 89.54(7)

O1-Cr1-O4 84.70(7)

O2-Cr1-O4 85.20(6)

C1-Cr1-O4 171.55(7)

C12-O1-Cr1 130.97(15)

C22-O2-Cr1 126.29(14)

Cr1#1-O3-Cr1 158.69(14)

C30-O4-C27 109.45(19)

C30-O4-Cr1 127.19(15)

C27-O4-Cr1 123.27(14)

C6-C1-C2 119.4(2)

C6-C1-Cr1 121.40(17)

C2-C1-Cr1 119.08(17)

C3-C2-C1 119.1(2)

C3-C2-C17 117.7(2)

C1-C2-C17 123.1(2)

C4-C3-C2 121.0(2)

C5-C4-C3 120.5(2)

C4-C5-C6 121.1(2)

C5-C6-C1 119.0(2)

C5-C6-C7 117.2(2)

C1-C6-C7 123.7(2)

C8-C7-C12 117.8(2)

C8-C7-C6 121.0(2)

C12-C7-C6 121.1(2)

C9-C8-C7 121.2(3)

C8-C9-C10 119.9(3)

C9-C10-C11 122.5(3)

C10-C11-C12 116.7(3)

C10-C11-C13 122.0(2)

C12-C11-C13 121.3(2)

O1-C12-C7 120.4(2)

O1-C12-C11 118.0(2)

C7-C12-C11 121.6(2)

C15-C13-C16 111.1(2)

C15-C13-C14 107.5(2)

C16-C13-C14 107.3(2)

C15-C13-C11 110.0(2)

C16-C13-C11 109.3(2)

C14-C13-C11 111.6(2)

C18-C17-C22 117.6(2)

315

Table A- 21. Continued. Bond Angles Bond Angles

C18-C17-C2 120.4(2)

C22-C17-C2 121.9(2)

C19-C18-C17 121.4(2)

C18-C19-C20 120.3(2)

C19-C20-C21 121.8(2)

C20-C21-C22 116.9(2)

C20-C21-C23 120.7(2)

C22-C21-C23 122.3(2)

O2-C22-C17 119.84(19)

O2-C22-C21 118.3(2)

C17-C22-C21 121.9(2)

C25-C23-C21 110.0(2)

C25-C23-C26 111.2(2)

C21-C23-C26 109.8(2)

C25-C23-C24 107.8(2)

C21-C23-C24 111.62(19)

C26-C23-C24 106.3(2)

O4-C27-C28 105.8(2)

C27-C28-C29 102.7(2)

C28-C29-C30 103.2(2)

O4-C30-C29 105.4(2)

O5-C32-C31 109.7(11)

C32-O5-C33 120.9(8)

C34-C33-O5 115.1(8)

O5'-C32'-C31' 144.4(11)

C32'-O5'-C33' 113.1(9)

O5'-C33'-C34' 102.9(11)



displacement factor exponent takes the form: -22[ h2 a*2U11 + ... + 2 h k

a* b* U12 ]. U11 U22 U33 U23 U13 U12

Cr1 23(1) 22(1) 17(1) -2(1) 6(1) 0(1)

O1 31(1) 27(1) 27(1) -3(1) 13(1) 3(1)

O2 28(1) 24(1) 17(1) -3(1) 8(1) -3(1)

O3 26(1) 27(1) 23(1) 0 5(1) 0

O4 29(1) 35(1) 23(1) 5(1) 5(1) -4(1)

C1 20(1) 24(1) 23(1) 1(1) 4(1) -1(1)

C2 24(1) 24(1) 25(1) 1(1) 7(1) 0(1)

C3 40(2) 30(1) 30(1) 5(1) 15(1) -1(1)

C4 52(2) 26(1) 44(2) 9(1) 22(1) -2(1)

C5 49(2) 19(1) 44(2) -1(1) 17(1) -1(1)

C6 29(1) 25(1) 30(1) -1(1) 9(1) 0(1)

C7 29(1) 27(1) 35(1) -5(1) 8(1) 4(1)

C8 44(2) 29(1) 48(2) -8(1) 11(1) 1(1)

C9 57(2) 35(2) 48(2) -21(1) 10(2) 5(1)

C10 46(2) 47(2) 34(2) -17(1) 10(1) 13(1)

C11 27(1) 42(2) 30(1) -7(1) 5(1) 12(1)

C12 25(1) 30(1) 28(1) -6(1) 4(1) 6(1)

C13 34(1) 53(2) 28(1) -5(1) 12(1) 9(1)

C14 45(2) 75(2) 36(2) -12(2) 16(1) 17(2)

C15 45(2) 57(2) 29(2) -1(1) 14(1) 12(1)

C16 35(2) 59(2) 39(2) -4(1) 15(1) 2(1)

C17 25(1) 24(1) 19(1) 1(1) 5(1) 1(1)

C18 37(1) 33(1) 25(1) 4(1) 13(1) -2(1)

C19 45(2) 41(2) 25(1) -6(1) 18(1) -2(1)

C20 41(2) 31(1) 26(1) -9(1) 10(1) -1(1)

C21 28(1) 25(1) 23(1) -1(1) 4(1) 1(1)

C22 23(1) 25(1) 16(1) -1(1) 4(1) 1(1)

C23 36(1) 22(1) 29(1) -6(1) 10(1) -5(1)

C24 52(2) 28(2) 45(2) -11(1) 17(1) -10(1)

C25 48(2) 28(1) 36(2) 2(1) 13(1) -2(1)

C26 35(2) 35(2) 43(2) -6(1) 12(1) -9(1)

C27 34(1) 46(2) 37(2) 1(1) 13(1) -9(1)

316

Table A- 22. Continued U11 U22 U33 U23 U13 U12

C28 63(2) 52(2) 53(2) 5(2) 28(2) -17(2)

C29 89(2) 43(2) 33(2) 10(1) 20(2) -3(2)

C30 46(2) 42(2) 29(1) 10(1) 3(1) 3(1)

Figure A- 168. X-ray structure of 5.








faces.

The structure was solved by the Direct Methods in SHELXTL6, and

refined using full-matrix least squares. The non-H atoms were treated anisotropically,

317

whereas the hydrogen atoms were calculated in ideal positions and were riding on their

respective carbon atoms. In addition to the Cr complex, a dichloromethane solvent

molecule was found and refined. A total of 655 parameters were refined in the final

cycle of refinement using 9004 reflections with I > 2(I) to yield R1 and wR2 of 3.25%

and 8.48%, respectively. Refinement was done using F2.




Empirical formula C63H59Cl2CrO4P2





Space group P2(1)/n

Unit cell dimensions a = = 20.0532(14) Å = 90°.

b = 11.8927(8) Å = 112.310(1)°.

c = 23.8911(17) Å = 90°.

Volume 5271.2(6) Å3

Z 4



F(000) 2228



Index ranges -24≤h≤24, -14≤k≤14, -28≤l≤29











Largest diff. peak and hole 0.438 and -0.439 e.Å-3 R1 = (||Fo| - |Fc||) / |Fo|

wR2 = [w(Fo2 - Fc

2)2] / wFo22]]1/2

S = [w(Fo2 - Fc

2)2] / (n-p)]1/2

w= 1/[2(Fo2)+(m*p)

2+n*p], p = [max(Fo


318


Atom X Y Z U(eq)

Cr1 4987(1) 4834(1) 2215(1) 12(1)

P1 4353(1) 6479(1) 3054(1) 14(1)

P2 6226(1) 3809(1) 1654(1) 13(1)

Cl1 931(1) 3063(1) 64(1) 40(1)

Cl2 -309(1) 4276(1) -788(1) 47(1)

O1 5542(1) 4307(1) 3018(1) 14(1)

O2 4463(1) 5484(1) 1429(1) 14(1)

O3 4434(1) 5820(1) 2548(1) 17(1)

O4 5768(1) 4396(1) 1937(1) 16(1)

C1 4362(1) 3489(1) 2043(1) 15(1)

C2 4630(1) 2462(1) 2342(1) 16(1)

C3 4171(1) 1522(2) 2192(1) 21(1)

C4 3495(1) 1580(2) 1733(1) 25(1)

C5 3244(1) 2582(2) 1429(1) 22(1)

C6 3658(1) 3568(1) 1595(1) 16(1)

C7 5381(1) 2330(1) 2805(1) 16(1)

C8 5794(1) 3262(1) 3136(1) 14(1)

C9 6477(1) 3076(1) 3618(1) 16(1)

C10 6741(1) 1981(2) 3729(1) 18(1)

C11 6359(1) 1075(1) 3384(1) 19(1)

C12 5691(1) 1254(1) 2930(1) 18(1)

C13 6910(1) 4070(1) 3997(1) 18(1)

C14 6463(1) 4707(2) 4292(1) 20(1)

C15 7132(1) 4885(2) 3596(1) 21(1)

C16 7608(1) 3668(2) 4510(1) 26(1)

C17 3330(1) 4658(1) 1312(1) 16(1)

C18 3748(1) 5587(1) 1251(1) 15(1)

C19 3400(1) 6618(1) 992(1) 17(1)

C20 2650(1) 6676(2) 804(1) 20(1)

C21 2242(1) 5772(2) 861(1) 22(1)

C22 2579(1) 4781(2) 1115(1) 19(1)

C23 3830(1) 7645(2) 927(1) 19(1)

C24 4204(1) 7365(2) 488(1) 24(1)

C25 3345(1) 8675(2) 668(1) 31(1)

C26 4396(1) 8005(2) 1545(1) 25(1)

C27 4092(1) 5625(1) 3558(1) 16(1)

C28 4423(1) 4579(2) 3736(1) 21(1)

C29 4246(1) 3929(2) 4146(1) 26(1)

C30 3744(1) 4313(2) 4369(1) 24(1)

C31 3408(1) 5343(2) 4186(1) 22(1)

C32 3581(1) 6004(2) 3783(1) 19(1)

C33 3661(1) 7520(1) 2763(1) 17(1)

C34 3002(1) 7165(2) 2327(1) 23(1)

C35 2427(1) 7908(2) 2127(1) 32(1)

C36 2510(1) 8997(2) 2352(1) 35(1)

C37 3163(1) 9361(2) 2766(1) 29(1)

C38 3744(1) 8619(2) 2981(1) 23(1)

C39 5184(1) 7157(1) 3512(1) 16(1)

C40 5317(1) 7462(2) 4108(1) 23(1)

C41 5966(1) 7967(2) 4456(1) 26(1)

C42 6488(1) 8144(2) 4218(1) 27(1)

319


C43 6359(1) 7838(2) 3623(1) 26(1)

C44 5705(1) 7355(2) 3269(1) 21(1)

C45 5825(1) 2501(1) 1308(1) 16(1)

C46 6224(1) 1629(2) 1199(1) 21(1)

C47 5878(1) 664(2) 902(1) 26(1)

C48 5135(1) 568(2) 717(1) 27(1)

C49 4734(1) 1438(2) 818(1) 27(1)

C50 5076(1) 2410(2) 1110(1) 21(1)

C51 7125(1) 3515(1) 2188(1) 14(1)

C52 7686(1) 4276(1) 2275(1) 17(1)

C53 8368(1) 4071(2) 2714(1) 21(1)

C54 8490(1) 3114(2) 3066(1) 22(1)

C55 7930(1) 2367(2) 2994(1) 24(1)

C56 7249(1) 2563(2) 2557(1) 19(1)

C57 6296(1) 4668(1) 1056(1) 15(1)

C58 5788(1) 5514(2) 821(1) 21(1)

C59 5790(1) 6148(2) 331(1) 26(1)

C60 6293(1) 5932(2) 76(1) 20(1)

C61 6800(1) 5088(2) 308(1) 19(1)

C62 6802(1) 4455(2) 796(1) 18(1)

C63 581(1) 3840(2) -612(1) 47(1)


Cr1-O1 1.9211(11)

Cr1-O2 1.9312(11)

Cr1-C1 1.9761(17)

Cr1-O3 1.9771(12)

Cr1-O4 1.9896(11)

P1-O3 1.5007(12)

P1-C33 1.7915(17)

P1-C27 1.7986(17)

P1-C39 1.7997(17)

P2-O4 1.5029(12)

P2-C45 1.8007(17)

P2-C57 1.8040(16)

P2-C51 1.8047(16)

Cl1-C63 1.759(2)

Cl2-C63 1.750(2)

O1-C8 1.330(2)

O2-C18 1.3384(19)

C1-C2 1.413(2)

C1-C6 1.415(2)

C2-C3 1.406(2)

C2-C7 1.501(2)

C3-C4 1.384(3)

C4-C5 1.387(3)

C5-C6 1.403(2)

C6-C17 1.495(2)

C7-C12 1.403(2)

C7-C8 1.429(2)

C8-C9 1.432(2)

C9-C10 1.393(2)

C9-C13 1.542(2)

C10-C11 1.395(2)

C11-C12 1.383(2)

C13-C14 1.533(2)

C13-C15 1.544(2)

C13-C16 1.545(2)

C17-C22 1.403(2)

C17-C18 1.427(2)

C18-C19 1.431(2)

C19-C20 1.398(2)

C19-C23 1.538(2)

C20-C21 1.389(3)

C21-C22 1.380(3)

C23-C25 1.540(2)

C23-C24 1.540(2)

C23-C26 1.542(2)

C27-C28 1.398(2)

C27-C32 1.399(2)

C28-C29 1.394(3)

C29-C30 1.383(3)

C30-C31 1.387(3)

C31-C32 1.387(2)

C33-C38 1.393(2)

C33-C34 1.402(2)

C34-C35 1.385(3)

C35-C36 1.389(3)

C36-C37 1.377(3)

C37-C38 1.395(3)

C39-C40 1.393(2)

320


C39-C44 1.396(2)

C40-C41 1.386(3)

C41-C42 1.384(3)

C42-C43 1.393(3)

C43-C44 1.386(3)

C45-C46 1.394(2)

C45-C50 1.396(2)

C46-C47 1.388(3)

C47-C48 1.389(3)

C48-C49 1.386(3)

C49-C50 1.389(3)

C51-C56 1.397(2)

C51-C52 1.398(2)

C52-C53 1.392(2)

C53-C54 1.382(3)

C54-C55 1.389(3)

C55-C56 1.388(2)

C57-C58 1.389(2)

C57-C62 1.399(2)

C58-C59 1.394(2)

C59-C60 1.386(3)

C60-C61 1.385(2)

C61-C62 1.387(2)



O1-Cr1-O2 175.28(5)

O1-Cr1-C1 91.46(6)

O2-Cr1-C1 93.07(6)

O1-Cr1-O3 89.59(5)

O2-Cr1-O3 88.40(5)

C1-Cr1-O3 98.96(6)

O1-Cr1-O4 90.97(5)

O2-Cr1-O4 89.24(5)

C1-Cr1-O4 103.62(6)

O3-Cr1-O4 157.38(5)

O3-P1-C33 110.65(7)

O3-P1-C27 113.16(7)

C33-P1-C27 105.68(8)

O3-P1-C39 111.47(7)

C33-P1-C39 109.12(8)

C27-P1-C39 106.47(8)

O4-P2-C45 111.40(7)

O4-P2-C57 109.74(7)

C45-P2-C57 106.36(7)

O4-P2-C51 112.84(7)

C45-P2-C51 108.03(8)

C57-P2-C51 108.22(8)

C8-O1-Cr1 123.01(10)

C18-O2-Cr1 117.9(1)

P1-O3-Cr1 151.94(7)

P2-O4-Cr1 164.78(8)

C2-C1-C6 121.22(15)

C2-C1-Cr1 120.29(12)

C6-C1-Cr1 118.43(12)

C3-C2-C1 118.14(15)

C3-C2-C7 118.74(15)

C1-C2-C7 123.12(15)

C4-C3-C2 120.83(16)

C3-C4-C5 120.57(16)

C4-C5-C6 120.77(16)

C5-C6-C1 118.15(15)

C5-C6-C17 119.06(14)

C1-C6-C17 122.75(15)

C12-C7-C8 118.25(15)

C12-C7-C2 119.44(15)

C8-C7-C2 122.30(15)

O1-C8-C7 120.97(14)

O1-C8-C9 118.97(14)

C7-C8-C9 120.01(15)

C10-C9-C8 118.41(15)

C10-C9-C13 121.10(15)

C8-C9-C13 120.49(14)

C9-C10-C11 121.73(15)

C12-C11-C10 119.67(16)

C11-C12-C7 121.70(16)

C14-C13-C9 110.61(14)

C14-C13-C15 109.42(14)

C9-C13-C15 110.30(13)

C14-C13-C16 107.49(14)

C9-C13-C16 111.57(14)

C15-C13-C16 107.34(14)

C22-C17-C18 118.78(15)

C22-C17-C6 118.27(15)

C18-C17-C6 122.93(14)

O2-C18-C17 119.81(14)

O2-C18-C19 120.25(15)

C17-C18-C19 119.94(14)

C20-C19-C18 118.01(15)

C20-C19-C23 120.37(15)

C18-C19-C23 121.62(14)

C21-C20-C19 122.17(16)

C22-C21-C20 119.67(16)

C21-C22-C17 121.43(16)

C19-C23-C25 112.21(14)

C19-C23-C24 109.55(14)

C25-C23-C24 107.19(15)

C19-C23-C26 111.13(14)

C25-C23-C26 106.67(15)

C24-C23-C26 109.97(15)

321


C28-C27-C32 120.18(16)

C28-C27-P1 118.69(13)

C32-C27-P1 121.11(13)

C29-C28-C27 119.23(16)

C30-C29-C28 120.27(17)

C29-C30-C31 120.56(17)

C32-C31-C30 119.93(16)

C31-C32-C27 119.81(16)

C38-C33-C34 120.35(16)

C38-C33-P1 122.60(13)

C34-C33-P1 116.92(13)

C35-C34-C33 119.36(18)

C34-C35-C36 120.02(19)

C37-C36-C35 120.81(18)

C36-C37-C38 120.00(18)

C33-C38-C37 119.42(18)

C40-C39-C44 119.84(16)

C40-C39-P1 120.85(13)

C44-C39-P1 119.29(13)

C41-C40-C39 119.90(17)

C42-C41-C40 120.21(17)

C41-C42-C43 120.18(17)

C44-C43-C42 119.86(17)

C43-C44-C39 119.98(16)

C46-C45-C50 119.90(16)

C46-C45-P2 122.69(13)

C50-C45-P2 117.27(13)

C47-C46-C45 119.96(17)

C46-C47-C48 119.85(18)

C49-C48-C47 120.49(17)

C48-C49-C50 119.92(17)

C49-C50-C45 119.87(17)

C56-C51-C52 119.43(15)

C56-C51-P2 119.62(13)

C52-C51-P2 120.74(13)

C53-C52-C51 120.16(16)

C54-C53-C52 120.02(16)

C53-C54-C55 120.15(16)

C56-C55-C54 120.28(17)

C55-C56-C51 119.93(16)

C58-C57-C62 119.68(15)

C58-C57-P2 117.67(13)

C62-C57-P2 122.46(13)

C57-C58-C59 119.76(16)

C60-C59-C58 120.17(17)

C61-C60-C59 120.31(16)

C60-C61-C62 119.81(16)

C61-C62-C57 120.27(16)

Cl2-C63-Cl1 113.04(12)




U11 U22 U33 U23 U13 U12

W1 9(1) 13(1) 11(1) -1(1) 0(1) 0(1)

Cr1 11(1) 12(1) 12(1) 0(1) 4(1) 1(1)

P1 13(1) 14(1) 13(1) -1(1) 5(1) 2(1)

P2 12(1) 13(1) 13(1) 1(1) 5(1) 1(1)

Cl1 36(1) 49(1) 33(1) 3(1) 11(1) 2(1)

Cl2 41(1) 42(1) 64(1) 18(1) 27(1) 14(1)

O1 16(1) 13(1) 14(1) 0(1) 5(1) 2(1)

O2 11(1) 17(1) 15(1) 3(1) 5(1) 1(1)

O3 17(1) 18(1) 16(1) -1(1) 6(1) 3(1)

O4 15(1) 18(1) 16(1) 1(1) 8(1) 2(1)

C1 16(1) 16(1) 14(1) -2(1) 8(1) -1(1)

C2 18(1) 16(1) 16(1) -1(1) 8(1) -1(1)

C3 22(1) 15(1) 26(1) 3(1) 8(1) -2(1)

C4 22(1) 19(1) 31(1) -2(1) 7(1) -8(1)

C5 16(1) 23(1) 22(1) -2(1) 3(1) -5(1)

C6 16(1) 18(1) 15(1) -1(1) 7(1) -2(1)

C7 18(1) 17(1) 16(1) 2(1) 9(1) 1(1)

C8 15(1) 15(1) 14(1) 2(1) 8(1) 2(1)

C9 17(1) 17(1) 15(1) 2(1) 8(1) 1(1)

C10 17(1) 21(1) 18(1) 4(1) 7(1) 4(1)

C11 23(1) 14(1) 23(1) 5(1) 13(1) 6(1)

322


C12 22(1) 15(1) 20(1) 0(1) 10(1) -2(1)

C13 17(1) 18(1) 16(1) 0(1) 3(1) 2(1)

C14 22(1) 22(1) 16(1) -2(1) 6(1) 0(1)

C15 17(1) 21(1) 23(1) -2(1) 7(1) -2(1)

C16 22(1) 23(1) 23(1) -1(1) -1(1) 3(1)

C17 16(1) 20(1) 12(1) -1(1) 5(1) -2(1)

C18 13(1) 20(1) 11(1) -1(1) 4(1) 1(1)

C19 16(1) 20(1) 13(1) 0(1) 4(1) 1(1)

C20 17(1) 23(1) 18(1) 4(1) 4(1) 5(1)

C21 12(1) 33(1) 19(1) 4(1) 3(1) 2(1)

C22 15(1) 25(1) 17(1) 1(1) 4(1) -4(1)

C23 16(1) 17(1) 21(1) 3(1) 5(1) 2(1)

C24 31(1) 20(1) 25(1) 6(1) 15(1) 0(1)

C25 24(1) 20(1) 45(1) 10(1) 9(1) 4(1)

C26 26(1) 24(1) 24(1) 0(1) 7(1) -6(1)

C27 13(1) 18(1) 14(1) -1(1) 3(1) -3(1)

C28 19(1) 22(1) 24(1) 2(1) 10(1) 3(1)

C29 28(1) 20(1) 31(1) 7(1) 13(1) 4(1)

C30 27(1) 26(1) 22(1) 3(1) 11(1) -4(1)

C31 19(1) 28(1) 19(1) -2(1) 9(1) -1(1)

C32 17(1) 20(1) 18(1) -1(1) 5(1) 1(1)

C33 18(1) 18(1) 16(1) 4(1) 9(1) 4(1)

C34 22(1) 24(1) 21(1) 2(1) 6(1) 3(1)

C35 22(1) 40(1) 27(1) 5(1) 1(1) 11(1)

C36 35(1) 37(1) 31(1) 10(1) 11(1) 23(1)

C37 40(1) 20(1) 33(1) 2(1) 19(1) 12(1)

C38 27(1) 20(1) 23(1) 0(1) 12(1) 4(1)

C39 15(1) 15(1) 18(1) 0(1) 4(1) 1(1)

C40 20(1) 28(1) 20(1) -4(1) 9(1) -3(1)

C41 28(1) 30(1) 18(1) -5(1) 5(1) -6(1)

C42 24(1) 26(1) 25(1) 0(1) 3(1) -10(1)

C43 23(1) 30(1) 27(1) 2(1) 11(1) -8(1)

C44 23(1) 21(1) 19(1) 1(1) 9(1) -2(1)

C45 18(1) 15(1) 13(1) 2(1) 6(1) -1(1)

C46 21(1) 19(1) 23(1) -1(1) 6(1) 1(1)

C47 34(1) 16(1) 25(1) -2(1) 10(1) 3(1)

C48 37(1) 21(1) 21(1) -3(1) 9(1) -12(1)

C49 24(1) 35(1) 22(1) -6(1) 10(1) -11(1)

C50 19(1) 27(1) 17(1) -3(1) 8(1) -2(1)

C51 14(1) 16(1) 14(1) -1(1) 6(1) 3(1)

C52 20(1) 17(1) 17(1) 0(1) 8(1) 0(1)

C53 16(1) 26(1) 20(1) -3(1) 7(1) -4(1)

C54 14(1) 27(1) 22(1) 0(1) 4(1) 4(1)

C55 23(1) 20(1) 24(1) 6(1) 5(1) 3(1)

C56 18(1) 17(1) 21(1) 2(1) 6(1) -1(1)

C57 16(1) 14(1) 13(1) -1(1) 4(1) -2(1)

C58 21(1) 24(1) 22(1) 5(1) 12(1) 6(1)

C59 28(1) 25(1) 26(1) 10(1) 13(1) 10(1)

C60 24(1) 21(1) 16(1) 4(1) 8(1) -2(1)

C61 19(1) 23(1) 18(1) -2(1) 10(1) -1(1)

C62 18(1) 19(1) 18(1) 1(1) 7(1) 3(1)

C63 41(1) 50(2) 65(2) 27(1) 36(1) 13(1)

323

Figure A- 169. Molecular Structure of 6.








faces.

324




carbon atoms. The asymmetric unit consists of the Cr complex and two toluene solvent

molecules. A total of 593 parameters were refined in the final cycle of refinement using

7354 reflections with I > 2(I) to yield R1 and wR2 of 3.60% and 7.60%, respectively.

Refinement was done using F2.

SHELXTL6 (2000). Bruker-AXS, Madison, Wisconsin, USA. Table A- 28. Crystal data and structure refinement for 6. Item Value


Empirical formula C59H60CrO3P




Crystal system Triclinic

Space group P-1


b = 16.9424(15) Å = 101.572(2)°.

c = 25.884(2) Å = 90°.

Volume 4760.6(7) Å3

Z 4



F(000) 1908



Index ranges -14≤h≤14, -22≤k≤22, -33≤l≤33




Absorption correction Numerical








R1 = (||Fo| - |Fc||) / |Fo| wR2 = [w(Fo2 - Fc

2)2] / wFo22]]1/2

S = [w(Fo2 - Fc

2)2] / (n-p)]1/2 w= 1/[2(Fo2)+(m*p)

2+n*p], p = [max(Fo


325


Atom X Y Z U(eq)

Cr1 -218(1) 6781(1) 1991(1) 12(1)

P1 2582(1) 6690(1) 2818(1) 12(1)

O1 835(1) 6998(1) 1532(1) 13(1)

O2 -493(1) 6242(1) 2582(1) 13(1)

O4 -1255(1) 7424(1) 1869(1) 16(1)

C1 508(2) 7011(1) 1000(1) 14(1)

C2 867(2) 7658(1) 717(1) 16(1)

C3 546(2) 7620(1) 169(1) 19(1)

C4 -112(2) 6993(1) -94(1) 22(1)

C5 -470(2) 6376(1) 189(1) 20(1)

C6 -152(2) 6368(1) 739(1) 15(1)

C7 -542(2) 5706(1) 1041(1) 16(1)

C8 -687(2) 4959(1) 801(1) 20(1)

C9 -1150(2) 4332(1) 1040(1) 23(1)

C10 -1551(2) 4445(1) 1506(1) 21(1)

C11 -1434(2) 5185(1) 1756(1) 16(1)

C12 -833(2) 5808(1) 1545(1) 14(1)

C13 -2000(2) 5284(1) 2224(1) 15(1)

C14 -3059(2) 4855(1) 2266(1) 18(1)

C15 -3589(2) 4941(1) 2699(1) 19(1)

C16 -3073(2) 5456(1) 3098(1) 16(1)

C17 -2034(2) 5908(1) 3079(1) 15(1)

C18 -1506(2) 5817(1) 2622(1) 13(1)

C19 1551(2) 8373(1) 997(1) 17(1)

C20 768(2) 8777(1) 1351(1) 19(1)

C21 2798(2) 8108(1) 1325(1) 22(1)

C22 1823(2) 9002(1) 605(1) 27(1)

C23 -1469(2) 6462(1) 3529(1) 16(1)

C24 -2219(2) 6487(1) 3968(1) 24(1)

C25 -166(2) 6168(1) 3775(1) 20(1)

C26 -1430(2) 7313(1) 3324(1) 18(1)

C27 1281(2) 7271(1) 2557(1) 13(1)

C28 2276(2) 5650(1) 2722(1) 14(1)

C29 1961(2) 5355(1) 2208(1) 16(1)

C30 1635(2) 4572(1) 2124(1) 19(1)

C31 1618(2) 4075(1) 2550(1) 21(1)

C32 1935(2) 4362(1) 3061(1) 19(1)

C33 2262(2) 5147(1) 3149(1) 17(1)

C34 3116(2) 6852(1) 3519(1) 13(1)

C35 2454(2) 7311(1) 3810(1) 16(1)

C36 2895(2) 7422(1) 4348(1) 18(1)

C37 3988(2) 7078(1) 4593(1) 19(1)

C38 4660(2) 6622(1) 4305(1) 19(1)

C39 4226(2) 6512(1) 3771(1) 18(1)

C40 3880(2) 6962(1) 2531(1) 15(1)

C41 4371(2) 7716(1) 2650(1) 19(1)

C42 5376(2) 7964(1) 2450(1) 24(1)

C43 5894(2) 7463(1) 2127(1) 23(1)

C44 5420(2) 6721(1) 2015(1) 23(1)

C45 4418(2) 6460(1) 2216(1) 18(1)

C46 3300(2) 6126(1) 563(1) 52(1)

326


C47 3689(2) 5294(1) 711(1) 28(1)

C48 2891(2) 4777(1) 878(1) 34(1)

C49 3246(3) 4007(2) 1012(1) 50(1)

C50 4400(3) 3744(1) 980(1) 47(1)

C51 5205(2) 4257(2) 816(1) 44(1)

C52 4857(2) 5022(1) 683(1) 40(1)

C53 6617(2) 7217(1) 720(1) 34(1)

C54 6686(2) 8096(1) 635(1) 22(1)

C55 5813(2) 8608(1) 767(1) 25(1)

C56 5846(2) 9409(1) 661(1) 30(1)

C57 6767(2) 9716(1) 433(1) 31(1)

C58 7651(2) 9217(1) 313(1) 31(1)

C59 7610(2) 8416(1) 409(1) 26(1)


Cr1-O4 1.5699(11)

Cr1-O2 1.8576(11)

Cr1-O1 1.8615(11)

Cr1-C12 2.0495(17)

Cr1-C27 2.1483(17)

P1-C27 1.7650(17)

P1-C28 1.8007(18)

P1-C40 1.8060(17)

P1-C34 1.8144(17)

O1-C1 1.3535(19)

O2-C18 1.3551(19)

C1-C6 1.406(2)

C1-C2 1.419(2)

C2-C3 1.392(2)

C2-C19 1.533(2)

C3-C4 1.388(3)

C4-C5 1.379(3)

C5-C6 1.398(2)

C6-C7 1.481(2)

C7-C8 1.405(2)

C7-C12 1.415(2)

C8-C9 1.378(2)

C9-C10 1.380(2)

C10-C11 1.405(2)

C11-C12 1.415(2)

C11-C13 1.481(2)

C13-C18 1.397(2)

C13-C14 1.402(2)

C14-C15 1.374(2)

C15-C16 1.386(2)

C16-C17 1.392(2)

C17-C18 1.428(2)

C17-C23 1.529(2)

C19-C21 1.536(2)

C19-C22 1.541(2)

C19-C20 1.542(2)

C23-C24 1.536(2)

C23-C25 1.539(2)

C23-C26 1.541(2)

C27-H27B 0.938(18)

C27-H27A 0.933(19)

C28-C33 1.397(2)

C28-C29 1.399(2)

C29-C30 1.381(2)

C30-C31 1.391(2)

C31-C32 1.385(2)

C32-C33 1.385(2)

C34-C35 1.390(2)

C34-C39 1.396(2)

C35-C36 1.392(2)

C36-C37 1.379(2)

C37-C38 1.388(2)

C38-C39 1.382(2)

C40-C45 1.394(2)

C40-C41 1.399(2)

C41-C42 1.383(2)

C42-C43 1.392(3)

C43-C44 1.371(3)

C44-C45 1.390(2)

C46-C47 1.500(3)

C47-C48 1.375(3)

C47-C52 1.390(3)

C48-C49 1.386(3)

C49-C50 1.373(3)

C50-C51 1.373(3)

C51-C52 1.375(3)

C53-C54 1.509(3)

C54-C59 1.386(3)

C54-C55 1.393(3)

C55-C56 1.386(3)


327

Table A- 31. Bond angles [°] for 6. Bond Angle Bond Angle O4-Cr1-O2 105.86(6)

O4-Cr1-O1 105.10(6)

O2-Cr1-O1 148.23(5)

O4-Cr1-C12 107.32(6)

O2-Cr1-C12 88.71(6)

O1-Cr1-C12 88.82(6)

O4-Cr1-C27 107.62(6)

O2-Cr1-C27 82.05(6)

O1-Cr1-C27 82.01(6)

C12-Cr1-C27 145.05(7)

C27-P1-C28 112.13(8)

C27-P1-C40 110.91(8)

C28-P1-C40 109.69(8)

C27-P1-C34 112.10(8)

C28-P1-C34 107.45(8)

C40-P1-C34 104.20(8)

C1-O1-Cr1 125.4(1)

C18-O2-Cr1 126.87(10)

O1-C1-C6 118.91(15)

O1-C1-C2 119.43(15)

C6-C1-C2 121.63(15)

C3-C2-C1 116.69(16)

C3-C2-C19 121.25(16)

C1-C2-C19 122.05(15)

C4-C3-C2 122.45(17)

C5-C4-C3 119.86(17)

C4-C5-C6 120.59(17)

C5-C6-C1 118.74(16)

C5-C6-C7 120.37(16)

C1-C6-C7 120.85(15)

C8-C7-C12 119.45(16)

C8-C7-C6 117.92(15)

C12-C7-C6 122.54(16)

C9-C8-C7 120.98(17)

C8-C9-C10 119.95(17)

C9-C10-C11 120.70(17)

C10-C11-C12 119.67(16)

C10-C11-C13 117.56(16)

C12-C11-C13 122.72(15)

C7-C12-C11 118.42(15)

C7-C12-Cr1 120.44(12)

C11-C12-Cr1 120.76(12)

C18-C13-C14 119.17(15)

C18-C13-C11 120.64(15)

C14-C13-C11 120.18(16)

C15-C14-C13 120.64(16)

C14-C15-C16 119.69(16)

C15-C16-C17 122.69(16)

C16-C17-C18 116.70(16)

C16-C17-C23 121.64(15)

C18-C17-C23 121.64(15)

O2-C18-C13 119.61(15)

O2-C18-C17 119.31(15)

C13-C18-C17 121.07(15)

C2-C19-C21 109.56(14)

C2-C19-C22 112.21(15)

C21-C19-C22 107.03(14)

C2-C19-C20 110.35(14)

C21-C19-C20 110.64(14)

C22-C19-C20 106.98(15)

C17-C23-C24 112.44(14)

C17-C23-C25 108.86(14)

C24-C23-C25 107.75(14)

C17-C23-C26 110.33(14)

C24-C23-C26 106.58(14)

C25-C23-C26 110.84(14)

P1-C27-Cr1 120.32(9)

P1-C27-H27B 109.5(11)

Cr1-C27-H27B 101.8(11)

P1-C27-H27A 108.2(11)

Cr1-C27-H27A 107.2(11)

H27B-C27-H27A 109.5(16)

C33-C28-C29 119.55(16)

C33-C28-P1 121.33(13)

C29-C28-P1 118.97(13)

C30-C29-C28 120.07(16)

C29-C30-C31 120.09(17)

C32-C31-C30 120.17(17)

C31-C32-C33 120.11(17)

C32-C33-C28 120.00(16)

C35-C34-C39 119.30(15)

C35-C34-P1 121.67(13)

C39-C34-P1 119.03(13)

C34-C35-C36 120.02(16)

C37-C36-C35 120.12(17)

C36-C37-C38 120.30(16)

C39-C38-C37 119.72(16)

C38-C39-C34 120.53(16)

C45-C40-C41 119.49(16)

C45-C40-P1 123.71(14)

C41-C40-P1 116.78(13)

C42-C41-C40 120.15(17)

C41-C42-C43 119.94(18)

C44-C43-C42 119.98(17)

C43-C44-C45 120.86(17)

C44-C45-C40 119.56(17)

C48-C47-C52 117.9(2)

C48-C47-C46 120.6(2)

C52-C47-C46 121.5(2)

C47-C48-C49 120.7(2)

C50-C49-C48 120.7(2)

C49-C50-C51 119.0(2)

C51-C52-C47 121.2(2)

C59-C54-C55 117.87(19)

C59-C54-C53 120.73(18)

328

Table A- 31. Continued. Bond Angle Bond Angle C55-C54-C53 121.38(18)

C56-C55-C54 120.98(18)

C57-C56-C55 120.30(19)

C58-C57-C56 119.1(2)

C57-C58-C59 120.75(19)

C58-C59-C54 120.92(19)




U11 U22 U33 U23 U13 U12

Cr1 12(1) 12(1) 11(1) 0(1) 3(1) 0(1)

P1 13(1) 13(1) 11(1) 0(1) 2(1) 0(1)

O1 15(1) 16(1) 10(1) 0(1) 3(1) -1(1)

O2 14(1) 14(1) 11(1) 0(1) 4(1) -4(1)

O4 15(1) 15(1) 16(1) -2(1) 2(1) 1(1)

C1 13(1) 18(1) 12(1) 0(1) 4(1) 4(1)

C2 15(1) 18(1) 14(1) 1(1) 6(1) 4(1)

C3 21(1) 22(1) 16(1) 4(1) 8(1) 6(1)

C4 26(1) 31(1) 10(1) 0(1) 5(1) 8(1)

C5 22(1) 23(1) 16(1) -6(1) 4(1) 2(1)

C6 15(1) 18(1) 14(1) -2(1) 5(1) 2(1)

C7 13(1) 18(1) 16(1) -4(1) 2(1) 0(1)

C8 21(1) 22(1) 18(1) -7(1) 6(1) -1(1)

C9 25(1) 16(1) 29(1) -9(1) 10(1) -4(1)

C10 23(1) 16(1) 25(1) -4(1) 9(1) -6(1)

C11 14(1) 16(1) 17(1) -2(1) 2(1) 0(1)

C12 12(1) 14(1) 14(1) -3(1) 1(1) 1(1)

C13 17(1) 13(1) 16(1) 2(1) 5(1) 1(1)

C14 21(1) 13(1) 20(1) -2(1) 3(1) -4(1)

C15 18(1) 18(1) 22(1) 2(1) 6(1) -4(1)

C16 17(1) 16(1) 17(1) 3(1) 7(1) 2(1)

C17 16(1) 14(1) 14(1) 2(1) 2(1) 2(1)

C18 14(1) 11(1) 14(1) 4(1) 3(1) 1(1)

C19 20(1) 16(1) 17(1) 4(1) 6(1) -1(1)

C20 23(1) 16(1) 20(1) 0(1) 6(1) 0(1)

C21 19(1) 22(1) 24(1) 2(1) 5(1) -2(1)

C22 34(1) 22(1) 25(1) 5(1) 10(1) -4(1)

C23 18(1) 19(1) 11(1) 0(1) 5(1) -1(1)

C24 28(1) 29(1) 16(1) -4(1) 10(1) -6(1)

C25 21(1) 23(1) 15(1) 1(1) 1(1) -1(1)

C26 23(1) 17(1) 16(1) -2(1) 6(1) 1(1)

C27 14(1) 12(1) 13(1) -1(1) 4(1) 0(1)

C28 12(1) 13(1) 16(1) 1(1) 3(1) 1(1)

C29 18(1) 17(1) 13(1) 2(1) 2(1) 4(1)

C30 23(1) 17(1) 16(1) -4(1) 2(1) 2(1)

C31 24(1) 13(1) 26(1) -2(1) 5(1) -1(1)

C32 22(1) 16(1) 20(1) 4(1) 6(1) 0(1)

C33 17(1) 20(1) 15(1) 0(1) 3(1) 2(1)

C34 14(1) 12(1) 14(1) 1(1) 3(1) -2(1)

C35 15(1) 16(1) 16(1) 3(1) 2(1) 1(1)

C36 22(1) 18(1) 15(1) -2(1) 5(1) 1(1)

C37 22(1) 21(1) 12(1) 0(1) 0(1) -2(1)

C38 15(1) 22(1) 19(1) 4(1) 0(1) 1(1)

329


C39 17(1) 18(1) 18(1) 0(1) 4(1) 1(1)

C40 13(1) 17(1) 14(1) 3(1) 2(1) 2(1)

C41 16(1) 20(1) 21(1) 0(1) 5(1) 1(1)

C42 17(1) 22(1) 30(1) 6(1) 2(1) -1(1)

C43 14(1) 31(1) 26(1) 11(1) 7(1) 3(1)

C44 22(1) 27(1) 22(1) 6(1) 10(1) 8(1)

C45 19(1) 18(1) 19(1) 2(1) 6(1) 3(1)

C46 58(2) 36(2) 62(2) 10(1) 14(1) 11(1)

C47 30(1) 25(1) 29(1) 0(1) 4(1) 2(1)

C48 32(1) 38(1) 37(1) -2(1) 15(1) 1(1)

C49 68(2) 37(2) 52(2) 3(1) 31(1) -10(1)

C50 75(2) 29(1) 36(1) 4(1) 8(1) 16(1)

C51 35(1) 46(2) 48(2) -5(1) 3(1) 13(1)

C52 30(1) 38(1) 55(2) -1(1) 13(1) 0(1)

C53 35(1) 35(1) 28(1) 2(1) -1(1) 0(1)

C54 19(1) 32(1) 13(1) -2(1) -3(1) -1(1)

C55 18(1) 40(1) 19(1) -8(1) 4(1) -6(1)

C56 26(1) 37(1) 27(1) -12(1) 2(1) 4(1)

C57 39(1) 30(1) 21(1) -2(1) -2(1) -4(1)

C58 28(1) 47(2) 18(1) -1(1) 6(1) -10(1)

C59 20(1) 41(1) 18(1) -5(1) 3(1) 3(1)

330


X-Ray experimental: X-Ray Intensity data were collected at 100 K on a Bruker

DUO diffractometer using MoK radiation ( = 0.71073 Å) and an APEXII CCD area

detector. Raw data frames were read by program SAINT1 and integrated using 3D

profiling algorithms. The resulting data were reduced to produce hkl reflections and

their intensities and estimated standard deviations. The data were corrected for Lorentz

and polarization effects and numerical absorption corrections were applied based on

indexed and measured faces.

The structure was solved and refined in SHELXTL6.1, using full-matrix least-

squares refinement. The non-H atoms were refined with anisotropic thermal

parameters and all of the H atoms were calculated in idealized positions and refined

riding on their parent atoms. The C28 unit is disordered and was refined in two parts

331

(against the minor part C28’). Their site occupation factors were fxed at 50% ratio after

refined to this value. In the final cycle of refinement, 7092 reflections (of which 5724 are

observed with I > 2(I)) were used to refine 412 parameters and the resulting R1, wR2

and S (goodness of fit) were 2.42%, 4.73% and 1.056, respectively. The refinement

was carried out by minimizing the wR2 function using F2 rather than F values. R1 is

calculated to provide a reference to the conventional R value but its function is not

minimized. SHELXTL6 (2008). Bruker-AXS, Madison, Wisconsin, USA.



Empirical formula C29 H31 F12 N O3 W





Space group P21/n


b = 9.5278(15) Å = 97.389(3)°.

c = 28.609(5) Å = 90°.

Volume 3085.4(8) Å3

Z 4



F(000) 1672



Index ranges -14≤h≤14, -12≤k≤12, -37≤l≤37












wR2 = [w(Fo2 - Fc

2)2] / wFo22]]1/2

S = [w(Fo2 - Fc

2)2] / (n-p)]1/2

w= 1/[2(Fo2)+(m*p)

2+n*p], p = [max(Fo


332


Atom X Y Z U(eq)

W1 2542(1) 10022(1) 3572(1) 11(1)

F1 -169(2) 9337(2) 4292(1) 25(1)

F2 -986(1) 8840(2) 3594(1) 24(1)

F3 -989(1) 7324(2) 4146(1) 22(1)

F4 -145(2) 6522(2) 3193(1) 25(1)

F5 330(2) 5315(2) 3824(1) 23(1)

F6 1667(2) 5973(2) 3408(1) 24(1)

F7 5320(2) 9786(2) 2600(1) 22(1)

F8 5440(2) 11870(2) 2887(1) 20(1)

F9 6908(1) 10462(2) 3030(1) 20(1)

F10 5896(2) 12077(2) 3826(1) 25(1)

F11 6946(1) 10217(2) 3957(1) 21(1)

F12 5303(2) 10409(2) 4241(1) 19(1)

O1 1225(2) 8710(2) 3522(1) 13(1)

O2 4023(2) 10487(2) 3342(1) 13(1)

O3 1593(2) 11282(2) 3045(1) 18(1)

N1 3447(2) 8401(2) 3889(1) 11(1)

C1 874(2) 7769(3) 3846(1) 12(1)

C2 1784(2) 7498(3) 4282(1) 12(1)

C3 2994(2) 7754(3) 4276(1) 11(1)

C4 3782(2) 7388(3) 4674(1) 14(1)

C5 3396(3) 6796(3) 5064(1) 15(1)

C6 2201(3) 6538(3) 5077(1) 15(1)

C7 1421(2) 6892(3) 4685(1) 14(1)

C8 -329(3) 8312(3) 3973(1) 17(1)

C9 671(3) 6385(3) 3569(1) 17(1)

C10 1781(3) 5899(4) 5507(1) 24(1)

C11 5172(2) 10001(3) 3417(1) 12(1)

C12 5214(2) 8391(3) 3468(1) 11(1)

C13 4359(2) 7689(3) 3699(1) 12(1)

C14 4446(2) 6221(3) 3734(1) 14(1)

C15 5331(3) 5482(3) 3560(1) 17(1)

C16 6184(2) 6156(3) 3339(1) 17(1)

C17 6109(2) 7610(3) 3301(1) 15(1)

C18 5726(2) 10532(3) 2982(1) 16(1)

C19 5836(2) 10677(3) 3866(1) 15(1)

C20 7151(3) 5346(3) 3147(1) 25(1)

C21 2363(2) 11017(3) 4074(1) 13(1)

C22 2411(3) 11896(3) 4508(1) 16(1)

C23 2936(3) 11016(4) 4933(1) 27(1)

C24 1174(3) 12400(3) 4579(1) 23(1)

C25 3202(3) 13175(3) 4454(1) 26(1)

C26 890(3) 12526(3) 3135(1) 24(1)

C27 -347(3) 12141(4) 3193(2) 43(1)

C28 1156(7) 10644(8) 2583(2) 29(2)

C28' 1660(6) 11005(7) 2542(2) 22(1)

C29 1877(3) 9493(4) 2466(1) 35(1)

333


C21-W1-O2 110.62(11)

C21-W1-O1 103.76(10)

O2-W1-O1 144.97(8)

C21-W1-N1 98.87(11)

O2-W1-N1 84.79(8)

O1-W1-N1 83.51(9)

C21-W1-O3 100.02(10)

O2-W1-O3 90.97(8)

O1-W1-O3 89.50(8)

N1-W1-O3 160.94(8)

C1-O1-W1 130.73(16)

C11-O2-W1 136.15(16)

C26-O3-C28' 114.4(3)

C26-O3-C28 111.0(3)

C28'-O3-C28 27.1(3)

C26-O3-W1 124.91(17)

C28'-O3-W1 120.6(3)

C28-O3-W1 119.1(3)

C13-N1-C3 117.0(2)

C13-N1-W1 123.92(17)

C3-N1-W1 117.86(17)

O1-C1-C2 115.4(2)

O1-C1-C9 104.3(2)

C2-C1-C9 108.3(2)

O1-C1-C8 106.4(2)

C2-C1-C8 113.0(2)

C9-C1-C8 109.0(2)

C7-C2-C3 118.4(2)

C7-C2-C1 119.8(2)

C3-C2-C1 121.6(2)

C4-C3-C2 118.6(2)

C4-C3-N1 118.8(2)

C2-C3-N1 122.7(2)

C5-C4-C3 121.5(3)

C4-C5-C6 120.9(3)

C7-C6-C5 117.8(2)

C7-C6-C10 121.5(3)

C5-C6-C10 120.7(3)

C6-C7-C2 122.8(3)

F1-C8-F2 107.0(2)

F1-C8-F3 107.2(2)

F2-C8-F3 106.3(2)

F1-C8-C1 110.9(2)

F2-C8-C1 110.9(2)

F3-C8-C1 114.1(2)

F4-C9-F6 106.7(2)

F4-C9-F5 106.9(2)

F6-C9-F5 106.4(2)

F4-C9-C1 111.9(2)

F6-C9-C1 110.5(2)

F5-C9-C1 114.0(2)

O2-C11-C12 111.5(2)

O2-C11-C19 110.1(2)

C12-C11-C19 109.3(2)

O2-C11-C18 104.1(2)

C12-C11-C18 112.9(2)

C19-C11-C18 108.9(2)

C17-C12-C13 119.1(2)

C17-C12-C11 120.9(2)

C13-C12-C11 120.0(2)

C14-C13-N1 120.0(2)

C14-C13-C12 117.2(2)

N1-C13-C12 122.8(2)

C15-C14-C13 122.2(3)

C14-C15-C16 121.3(3)

C15-C16-C17 117.3(3)

C15-C16-C20 121.3(3)

C17-C16-C20 121.4(3)

C16-C17-C12 122.9(3)

F8-C18-F7 106.9(2)

F8-C18-F9 106.6(2)

F7-C18-F9 107.3(2)

F8-C18-C11 111.1(2)

F7-C18-C11 110.4(2)

F9-C18-C11 114.2(2)

F12-C19-F11 107.5(2)

F12-C19-F10 107.1(2)

F11-C19-F10 106.6(2)

F12-C19-C11 111.4(2)

F11-C19-C11 112.2(2)

F10-C19-C11 111.7(2)

C22-C21-W1 171.2(2)

C21-C22-C24 110.5(2)

C21-C22-C23 108.8(2)

C24-C22-C23 109.9(2)

C21-C22-C25 108.7(2)

C24-C22-C25 109.2(2)

C23-C22-C25 109.8(3)

O3-C26-C27 111.5(3)

C29-C28-O3 112.6(5)

O3-C28'-C29 110.3(4)

C28-C29-C28' 27.4(3)


334


W1-C21 1.754(3)

W1-O2 1.9419(18)

W1-O1 1.9462(18)

W1-N1 2.008(2)

W1-O3 2.1144(19)

F1-C8 1.332(3)

F2-C8 1.335(3)

F3-C8 1.340(3)

F4-C9 1.335(3)

F5-C9 1.340(3)

F6-C9 1.339(3)

F7-C18 1.336(3)

F8-C18 1.336(3)

F9-C18 1.340(3)

F10-C19 1.341(3)

F11-C19 1.335(3)

F12-C19 1.325(3)

O1-C1 1.385(3)

O2-C11 1.382(3)

O3-C26 1.473(3)

O3-C28' 1.474(6)

O3-C28 1.481(7)

N1-C13 1.409(3)

N1-C3 1.422(3)

C1-C2 1.538(4)

C1-C9 1.540(4)

C1-C8 1.554(4)

C2-C7 1.399(4)

C2-C3 1.405(4)

C3-C4 1.401(4)

C4-C5 1.371(4)

C5-C6 1.391(4)

C6-C7 1.383(4)

C6-C10 1.505(4)

C11-C12 1.541(4)

C11-C19 1.544(4)

C11-C18 1.551(4)

C12-C17 1.397(4)

C12-C13 1.414(4)

C13-C14 1.406(4)

C14-C15 1.375(4)

C15-C16 1.384(4)

C16-C17 1.392(4)

C16-C20 1.507(4)

C21-C22 1.494(4)

C22-C24 1.530(4)

C22-C23 1.534(4)

C22-C25 1.536(4)

C26-C27 1.488(5)

C28-C29 1.437(8)

C28'-C29 1.483(7)




U11 U22 U33 U23 U13 U12

W1 10(1) 11(1) 12(1) 3(1) 2(1) 1(1)

F1 22(1) 24(1) 31(1) -10(1) 8(1) 3(1)

F2 13(1) 33(1) 27(1) 9(1) 1(1) 4(1)

F3 14(1) 27(1) 27(1) 5(1) 8(1) -4(1)

F4 26(1) 29(1) 18(1) -5(1) -6(1) -6(1)

F5 31(1) 13(1) 26(1) 0(1) 4(1) -8(1)

F6 22(1) 23(1) 27(1) -10(1) 9(1) 0(1)

F7 31(1) 22(1) 12(1) -1(1) 4(1) -7(1)

F8 26(1) 15(1) 21(1) 6(1) 6(1) -3(1)

F9 14(1) 25(1) 24(1) 3(1) 9(1) -4(1)

F10 42(1) 11(1) 21(1) -1(1) -3(1) -4(1)

F11 14(1) 29(1) 20(1) -2(1) -2(1) -1(1)

F12 22(1) 24(1) 11(1) 0(1) 4(1) 0(1)

O1 10(1) 16(1) 12(1) 5(1) 0(1) -3(1)

O2 8(1) 15(1) 17(1) 6(1) 4(1) 2(1)

O3 18(1) 19(1) 15(1) 3(1) 0(1) 5(1)

N1 12(1) 10(1) 12(1) 3(1) 4(1) 2(1)

C1 13(1) 13(1) 11(1) 0(1) 3(1) -2(1)

C2 12(1) 12(1) 12(1) -2(1) 1(1) 0(1)

C3 16(1) 7(1) 10(1) 1(1) 4(1) 1(1)

335


C4 13(1) 14(1) 14(1) 2(1) 2(1) 0(1)

C5 18(1) 14(1) 11(1) 0(1) -3(1) -1(1)

C6 20(2) 16(1) 10(1) 0(1) 4(1) -2(1)

C7 14(1) 13(1) 15(1) -1(1) 4(1) -2(1)

C8 16(2) 18(1) 18(1) 2(1) 4(1) -2(1)

C9 17(1) 17(1) 18(1) -2(1) 2(1) -3(1)

C10 22(2) 32(2) 16(2) 7(1) 4(1) -5(1)

C11 10(1) 14(1) 13(1) 1(1) 1(1) -1(1)

C12 12(1) 12(1) 11(1) -1(1) 0(1) -1(1)

C13 11(1) 13(1) 12(1) 0(1) 1(1) 0(1)

C14 14(1) 15(1) 15(1) 2(1) 3(1) -1(1)

C15 17(2) 12(1) 20(1) 2(1) 1(1) 3(1)

C16 14(1) 17(1) 20(1) -3(1) 2(1) 2(1)

C17 13(1) 16(1) 16(1) -1(1) 3(1) -2(1)

C18 13(1) 17(1) 17(1) 1(1) 2(1) -3(1)

C19 16(1) 13(1) 15(1) 0(1) 1(1) -1(1)

C20 21(2) 19(2) 35(2) -3(1) 10(1) 5(1)

C21 12(1) 9(1) 18(1) 4(1) 4(1) 1(1)

C22 17(2) 13(1) 18(1) 0(1) 3(1) 0(1)

C23 38(2) 27(2) 14(1) -1(1) -2(1) 6(2)

C24 23(2) 23(2) 24(2) -3(1) 8(1) 2(1)

C25 28(2) 20(2) 30(2) -7(1) 10(1) -4(1)

C26 24(2) 18(2) 29(2) 5(1) 0(1) 11(1)

C27 22(2) 32(2) 74(3) 1(2) 7(2) 5(2)


336



detector.

Raw data frames were read by program SAINT1 and integrated using 3D profiling

algorithms. The resulting data were reduced to produce hkl reflections and their

intensities and estimated standard deviations. The data were corrected for Lorentz and

polarization effects and numerical absorption corrections were applied based on





riding on their parent atoms. In the final cycle of refinement, 7644 reflections (of which

6905 are observed with I > 2(I)) were used to refine 457 parameters and the resulting

R1, wR2 and S (goodness of fit) were 1.45%, 3.69% and 1.052, respectively. The

refinement was carried out by minimizing the wR2 function using F2 rather than F

values. R1 is calculated to provide a reference to the conventional R value but its

function is not minimized.









Space group P21/c


b = 15.7072(7) Å = 95.374(1)°.

337

Table A- 39. Continued. Item Value

Unit cell dimensions (continued) c = 19.9882(9) Å = 90°.

Volume 3327.8(3) Å3

Z 4



F(000) 1752



Index ranges -13≤h≤13, -20≤k≤20, -25≤l≤25












wR2 = [w(Fo2 - Fc

2)2] / wFo22]]1/2

S = [w(Fo2 - Fc

2)2] / (n-p)]1/2

w= 1/[2(Fo2)+(m*p)

2+n*p], p = [max(Fo



Atom X Y Z U(eq)

W1 8673(1) 598(1) 7892(1) 11(1)

F1 7832(1) -1208(1) 6441(1) 32(1)

F2 8375(1) -2040(1) 7270(1) 28(1)

F3 6512(1) -2135(1) 6766(1) 36(1)

F4 6882(1) -2032(1) 8278(1) 28(1)

F5 5113(1) -1625(1) 7770(1) 32(1)

F6 6092(1) -823(1) 8517(1) 27(1)

F7 8904(1) 2190(1) 9782(1) 24(1)

F8 10130(1) 2773(1) 9122(1) 26(1)

F9 8534(1) 3467(1) 9412(1) 25(1)

F10 9046(1) 3305(1) 7921(1) 27(1)

F11 7195(1) 3603(1) 8206(1) 23(1)

F12 7438(1) 2605(1) 7491(1) 21(1)

O1 8067(1) -570(1) 7793(1) 15(1)

O2 8856(1) 1626(1) 8453(1) 15(1)

N1 6835(1) 861(1) 7957(1) 13(1)

C1 6965(2) -903(1) 7468(1) 15(1)

C2 6095(2) -235(1) 7109(1) 13(1)

C3 6036(2) 584(1) 7386(1) 13(1)

C4 5202(2) 1178(1) 7062(1) 14(1)

C5 4463(2) 974(1) 6482(1) 15(1)

C6 4521(2) 166(1) 6194(1) 15(1)

338


C7 5329(2) -424(1) 6517(1) 15(1)

C8 7423(2) -1581(1) 6980(1) 23(1)

C9 6256(2) -1353(1) 8010(1) 21(1)

C10 3713(2) -54(1) 5556(1) 20(1)

C11 8117(2) 2293(1) 8633(1) 15(1)

C12 6823(2) 1997(1) 8808(1) 13(1)

C13 6242(2) 1309(1) 8456(1) 13(1)

C14 5050(2) 1043(1) 8618(1) 15(1)

C15 4448(2) 1443(1) 9114(1) 17(1)

C16 5014(2) 2125(1) 9471(1) 18(1)

C17 6188(2) 2393(1) 9309(1) 17(1)

C18 8924(2) 2690(1) 9241(1) 20(1)

C19 7953(2) 2959(1) 8059(1) 18(1)

C20 4356(2) 2569(1) 10010(1) 28(1)

C21 9510(2) 830(1) 7111(1) 15(1)

C22 10556(2) 552(1) 7576(1) 16(1)

C23 10325(2) 268(1) 8256(1) 15(1)

C24 9449(2) 1152(1) 6394(1) 19(1)

C25 8051(2) 1245(1) 6143(1) 24(1)

C26 10067(2) 516(1) 5947(1) 35(1)

C27 10080(2) 2033(1) 6374(1) 31(1)

C28 11910(2) 610(1) 7410(1) 22(1)

C29 11243(2) 60(1) 8818(1) 18(1)

C30 12231(2) -520(1) 8764(1) 26(1)

C31 13060(2) -703(1) 9321(1) 32(1)

C32 12921(2) -314(1) 9931(1) 32(1)

C33 11938(2) 250(1) 9992(1) 29(1)

C34 11096(2) 435(1) 9438(1) 22(1)


W1-C21 1.9046(16)

W1-C23 1.9106(18)

W1-O1 1.9489(11)

W1-O2 1.9631(11)

W1-N1 2.0158(14)

W1-C22 2.1589(18)

F1-C8 1.335(2)

F2-C8 1.331(2)

F3-C8 1.343(2)

F4-C9 1.342(2)

F5-C9 1.336(2)

F6-C9 1.336(2)

F7-C18 1.339(2)

F8-C18 1.334(2)

F9-C18 1.3435(19)

F10-C19 1.337(2)

F11-C19 1.3436(19)

F12-C19 1.335(2)

O1-C1 1.389(2)

O2-C11 1.3797(19)

N1-C13 1.417(2)

N1-C3 1.426(2)

C1-C2 1.533(2)

C1-C9 1.548(2)

C1-C8 1.552(2)

C2-C3 1.404(2)

C2-C7 1.404(2)

C3-C4 1.404(2)

C4-C5 1.377(2)

C5-C6 1.397(2)

C6-C7 1.383(2)

C6-C10 1.511(2)

C11-C12 1.525(2)

C11-C19 1.550(2)

C11-C18 1.551(2)

C12-C13 1.402(2)

C12-C17 1.404(2)

C13-C14 1.402(2)

C14-C15 1.382(2)

C15-C16 1.393(3)

C16-C17 1.386(2)

C16-C20 1.510(2)

C21-C22 1.450(3)

C21-C24 1.514(2)

339


C22-C23 1.473(2)

C22-C28 1.512(2)

C23-C29 1.455(2)

C24-C26 1.531(3)

C24-C25 1.533(3)

C24-C27 1.540(3)

C29-C34 1.394(3)

C29-C30 1.403(3)

C30-C31 1.385(3)

C31-C32 1.383(3)

C32-C33 1.386(3)

C33-C34 1.389(3)


Table A- 40. Bond angles [°] for13. Bond Angle Bond Angle

C21-W1-C23 83.09(7)

C21-W1-O1 105.78(6)

C23-W1-O1 93.85(6)

C21-W1-O2 106.38(6)

C23-W1-O2 88.16(6)

O1-W1-O2 147.78(5)

C21-W1-N1 122.99(7)

C23-W1-N1 153.60(6)

O1-W1-N1 83.38(5)

O2-W1-N1 80.83(5)

C21-W1-C22 41.22(7)

C23-W1-C22 41.90(7)

O1-W1-C22 104.24(6)

O2-W1-C22 98.61(6)

N1-W1-C22 163.57(6)

C1-O1-W1 131.31(10)

C11-O2-W1 138.19(11)

C13-N1-C3 116.32(14)

C13-N1-W1 130.22(11)

C3-N1-W1 113.36(10)

O1-C1-C2 114.02(13)

O1-C1-C9 106.85(14)

C2-C1-C9 109.08(14)

O1-C1-C8 104.57(14)

C2-C1-C8 112.85(14)

C9-C1-C8 109.19(14)

C3-C2-C7 118.82(15)

C3-C2-C1 119.39(15)

C7-C2-C1 121.78(15)

C4-C3-C2 118.50(15)

C4-C3-N1 118.07(14)

C2-C3-N1 123.32(15)

C5-C4-C3 121.35(15)

C4-C5-C6 120.94(16)

C7-C6-C5 117.82(16)

C7-C6-C10 121.38(15)

C5-C6-C10 120.79(15)

C6-C7-C2 122.54(15)

F2-C8-F1 107.27(15)

F2-C8-F3 106.62(14)

F1-C8-F3 107.86(15)

F2-C8-C1 111.70(15)

F1-C8-C1 110.52(14)

F3-C8-C1 112.62(16)

F6-C9-F5 106.99(15)

F6-C9-F4 106.68(15)

F5-C9-F4 106.91(14)

F6-C9-C1 110.76(13)

F5-C9-C1 112.46(15)

F4-C9-C1 112.69(15)

O2-C11-C12 112.18(13)

O2-C11-C19 110.28(13)

C12-C11-C19 109.54(14)

O2-C11-C18 102.83(14)

C12-C11-C18 112.89(13)

C19-C11-C18 108.93(13)

C13-C12-C17 118.71(15)

C13-C12-C11 119.03(14)

C17-C12-C11 122.26(15)

C14-C13-C12 118.67(15)

C14-C13-N1 119.17(15)

C12-C13-N1 122.14(15)

C15-C14-C13 121.41(16)

C14-C15-C16 120.66(16)

C17-C16-C15 118.04(15)

C17-C16-C20 121.02(17)

C15-C16-C20 120.93(17)

C16-C17-C12 122.50(16)

F8-C18-F7 106.83(15)

F8-C18-F9 106.42(14)

F7-C18-F9 107.32(13)

F8-C18-C11 111.85(14)

F7-C18-C11 110.29(14)

F9-C18-C11 113.77(15)

F12-C19-F10 106.87(13)

F12-C19-F11 106.97(15)

F10-C19-F11 106.87(13)

F12-C19-C11 110.96(13)

F10-C19-C11 112.80(15)

F11-C19-C11 112.03(13)

C22-C21-C24 132.01(15)

C22-C21-W1 78.84(10)

C24-C21-W1 149.07(14)

C21-C22-C23 119.89(15)

340


C21-C22-C28 122.13(16)

C23-C22-C28 117.78(16)

C21-C22-W1 59.94(9)

C23-C22-W1 60.00(9)

C28-C22-W1 173.09(13)

C29-C23-C22 128.45(16)

C29-C23-W1 151.93(13)

C22-C23-W1 78.11(10)

C21-C24-C26 110.58(15)

C21-C24-C25 107.23(14)

C26-C24-C25 109.11(16)

C21-C24-C27 110.19(15)

C26-C24-C27 111.07(16)

C25-C24-C27 108.54(16)

C34-C29-C30 119.30(17)

C34-C29-C23 117.92(16)

C30-C29-C23 122.75(17)

C31-C30-C29 119.94(19)

C32-C31-C30 120.3(2)

C31-C32-C33 120.31(19)

C32-C33-C34 119.92(19)

C33-C34-C29 120.24(18)




U11 U22 U33 U23 U13 U12

W1 9(1) 13(1) 11(1) -1(1) 0(1) 0(1)

F1 34(1) 38(1) 24(1) -6(1) 5(1) 14(1)

F2 24(1) 23(1) 36(1) -7(1) -7(1) 12(1)

F3 33(1) 20(1) 49(1) -16(1) -18(1) 4(1)

F4 25(1) 20(1) 39(1) 13(1) 0(1) 4(1)

F5 18(1) 29(1) 49(1) 14(1) -5(1) -10(1)

F6 31(1) 25(1) 26(1) 6(1) 10(1) 2(1)

F7 28(1) 29(1) 15(1) -1(1) -3(1) -2(1)

F8 18(1) 31(1) 28(1) -10(1) 0(1) -8(1)

F9 30(1) 20(1) 26(1) -11(1) 2(1) -2(1)

F10 21(1) 29(1) 31(1) 8(1) 7(1) -7(1)

F11 27(1) 16(1) 27(1) 2(1) 6(1) 4(1)

F12 27(1) 22(1) 14(1) 2(1) 1(1) -1(1)

O1 11(1) 13(1) 21(1) -2(1) -3(1) 0(1)

O2 12(1) 16(1) 16(1) -3(1) 1(1) -1(1)

N1 11(1) 14(1) 13(1) -2(1) 1(1) 0(1)

C1 13(1) 12(1) 20(1) -1(1) -2(1) 0(1)

C2 9(1) 14(1) 17(1) 0(1) 0(1) -1(1)

C3 11(1) 15(1) 13(1) 0(1) 3(1) -2(1)

C4 13(1) 14(1) 16(1) 0(1) 4(1) -1(1)

C5 12(1) 18(1) 15(1) 5(1) 2(1) 1(1)

C6 12(1) 20(1) 14(1) 1(1) 2(1) -3(1)

C7 14(1) 15(1) 17(1) -2(1) 1(1) -2(1)

C8 22(1) 19(1) 27(1) -5(1) -6(1) 4(1)

C9 16(1) 16(1) 30(1) 6(1) -3(1) -1(1)

C10 19(1) 24(1) 18(1) 0(1) -3(1) -2(1)

C11 16(1) 14(1) 13(1) -2(1) 1(1) -2(1)

C12 15(1) 13(1) 12(1) 2(1) 2(1) 1(1)

C13 13(1) 13(1) 11(1) 2(1) 2(1) 3(1)

C14 14(1) 16(1) 15(1) 4(1) 0(1) 1(1)

C15 14(1) 20(1) 18(1) 7(1) 5(1) 3(1)

C16 21(1) 19(1) 15(1) 4(1) 6(1) 6(1)

C17 21(1) 15(1) 14(1) 0(1) 2(1) 2(1)

C18 21(1) 19(1) 20(1) -5(1) 2(1) -2(1)

C19 17(1) 17(1) 20(1) 0(1) 5(1) -3(1)

341


C20 32(1) 30(1) 25(1) -3(1) 13(1) 4(1)

C21 12(1) 19(1) 15(1) -3(1) 3(1) -2(1)

C22 13(1) 18(1) 19(1) -4(1) 3(1) -1(1)

C23 13(1) 14(1) 17(1) -1(1) 0(1) 0(1)

C24 16(1) 29(1) 12(1) 1(1) 2(1) -2(1)

C25 19(1) 37(1) 15(1) 4(1) 0(1) -2(1)

C26 32(1) 55(1) 18(1) -4(1) 7(1) 10(1)

C27 29(1) 40(1) 22(1) 11(1) -3(1) -13(1)

C28 11(1) 30(1) 25(1) 1(1) 4(1) 1(1)

C29 12(1) 20(1) 21(1) 5(1) -1(1) -3(1)

C30 22(1) 25(1) 30(1) 4(1) -1(1) 4(1)

C31 22(1) 31(1) 42(1) 14(1) -2(1) 7(1)

C32 22(1) 43(1) 30(1) 22(1) -7(1) -6(1)

C33 24(1) 42(1) 20(1) 9(1) -1(1) -6(1)

C34 18(1) 29(1) 21(1) 7(1) 2(1) -1(1)







342



The structure was solved and refined in SHELXTL6.1, using full-matrix

least-squares refinement. The non-H atoms were refined with anisotropic thermal


riding on their parent atoms. The W center is disordered and was refined in two

positions with their site occupation factors dependently refine to 0.930(1) and 0.070(1),

for the major and minor parts respectively. It is worth noting here that the major W

center is symmetrically coordinated to the C21/C23 atoms while W2 is asymmetrically

coordinated to them; 1.882(3)/1.908(3) Å for W1 compared to2.387(6)/1.768(4) Å. In

the final cycle of refinement, 7570 reflections (of which 6697 are observed with I > 2(I))

were used to refine 441 parameters and the resulting R1, wR2 and S (goodness of fit)

were 2.20%, 4.82% and 1.089, respectively. The refinement was carried out by

minimizing the wR2 function using F2 rather than F values. R1 is calculated to provide a

reference to the conventional R value but its function is not minimized.








Space group P21/c


b = 9.8689(8) Å = 104.391(1)°.

c = 19.5331(16) Å = 90°.

Volume 3295.0(5) Å3

Z 4



F(000) 1720



343


Index ranges -22≤h≤22, -12≤k≤12, -25≤l≤25




Absorption correction Semi-empirical from equivalents








wR2 = [w(Fo2 - Fc

2)2] / wFo22]]1/2

S = [w(Fo2 - Fc

2)2] / (n-p)]1/2

w= 1/[2(Fo2)+(m*p)

2+n*p], p = [max(Fo



Atom X Y Z U(eq)

W1 2613(1) 1137(1) 8118(1) 15(1)

W2 2678(2) 1030(3) 8412(3) 38(1)

F1 1224(1) 963(2) 9763(1) 32(1)

F2 809(1) 2705(2) 9123(1) 34(1)

F3 22(1) 1070(2) 9161(1) 32(1)

F4 659(1) 545(2) 7273(1) 30(1)

F5 248(1) 2288(2) 7732(1) 33(1)

F6 -267(1) 334(2) 7801(1) 31(1)

F7 4121(1) 506(2) 6899(1) 40(1)

F8 4953(1) 483(2) 7909(1) 42(1)

F9 4865(1) -1236(2) 7222(1) 45(1)

F10 3652(1) -2318(2) 8712(1) 33(1)

F11 4386(1) -3044(2) 8064(1) 44(1)

F12 4794(1) -1458(2) 8819(1) 52(1)

O1 1715(1) 1362(2) 8529(1) 21(1)

O2 3606(1) 223(2) 8162(1) 23(1)

N1 2182(1) -767(2) 7962(1) 18(1)

C1 1029(1) 680(3) 8526(1) 18(1)

C2 1154(1) -845(2) 8626(1) 17(1)

C3 1712(1) -1484(3) 8334(1) 18(1)

C4 1799(2) -2893(3) 8414(1) 22(1)

C5 1362(2) -3640(3) 8776(1) 23(1)

C6 821(2) -3015(3) 9078(1) 22(1)

C7 722(1) -1628(3) 8992(1) 20(1)

C8 757(2) 1359(3) 9144(1) 24(1)

C9 405(2) 969(3) 7824(1) 23(1)

C10 358(2) -3822(3) 9491(2) 30(1)

C11 3800(2) -856(3) 7790(1) 22(1)

C12 3108(1) -1465(3) 7245(1) 21(1)

C13 2356(1) -1429(2) 7370(1) 19(1)

344


C14 1738(2) -1999(3) 6858(1) 22(1)

C15 1852(2) -2570(3) 6246(1) 25(1)

C16 2592(2) -2604(3) 6112(1) 25(1)

C17 3207(2) -2063(3) 6623(1) 25(1)

C18 4443(2) -281(3) 7451(2) 33(1)

C19 4166(2) -1933(3) 8348(2) 31(1)

C20 2719(2) -3167(3) 5431(2) 34(1)

C21 2509(2) 2400(3) 7378(1) 24(1)

C22 2945(2) 3188(3) 7978(2) 28(1)

C23 3166(2) 2579(3) 8677(1) 25(1)

C24 2188(2) 2786(3) 6614(2) 30(1)

C25 1922(2) 1468(3) 6207(2) 37(1)

C26 1479(2) 3727(3) 6554(2) 36(1)

C27 2805(2) 3456(4) 6292(2) 42(1)

C28 3201(2) 4628(3) 7880(2) 35(1)

C29 3631(2) 3070(3) 9381(2) 35(1)

C30 3195(2) 4179(4) 9680(2) 59(1)

C31 4448(2) 3544(4) 9343(2) 56(1)

C32 3717(2) 1810(4) 9859(2) 51(1)


W1-C21 1.882(3)

W1-C23 1.908(3)

W1-O2 1.9549(17)

W1-O1 1.9587(17)

W1-N1 2.022(2)

W1-C22 2.144(3)

W2-C21 2.387(6)

W2-C23 1.768(4)

W2-O1 1.800(3)

W2-O2 1.989(3)

W2-N1 2.074(3)

W2-C22 2.383(5)

W2-C21 2.387(6)

F1-C8 1.341(3)

F2-C8 1.334(3)

F3-C8 1.337(3)

F4-C9 1.333(3)

F5-C9 1.334(3)

F6-C9 1.332(3)

F7-C18 1.336(4)

F8-C18 1.333(3)

F9-C18 1.345(3)

F10-C19 1.338(3)

F11-C19 1.330(3)

F12-C19 1.337(3)

O1-C1 1.384(3)

O2-C11 1.380(3)

N1-C3 1.420(3)

N1-C13 1.426(3)

C1-C2 1.527(3)

C1-C8 1.556(3)

C1-C9 1.557(3)

C2-C7 1.400(3)

C2-C3 1.403(3)

C3-C4 1.403(4)

C4-C5 1.382(4)

C5-C6 1.386(4)

C6-C7 1.384(4)

C6-C10 1.510(3)

C11-C12 1.530(4)

C11-C19 1.544(4)

C11-C18 1.556(4)

C12-C17 1.400(4)

C12-C13 1.407(3)

C13-C14 1.401(3)

C14-C15 1.381(4)

C15-C16 1.393(4)

C16-C17 1.386(4)

C16-C20 1.510(4)

C21-C22 1.456(4)

C21-C24 1.508(4)

C22-C23 1.453(4)

C22-C28 1.517(4)

C23-C29 1.496(4)

C24-C27 1.536(4)

C24-C25 1.536(4)

C24-C26 1.539(4)

C29-C30 1.533(5)

C29-C31 1.535(5)

C29-C32 1.539(5)


345


C21-W1-C23 83.30(12)

C21-W1-O2 104.73(9)

C23-W1-O2 89.61(10)

C21-W1-O1 107.80(9)

C23-W1-O1 91.81(9)

O2-W1-O1 147.39(8)

C21-W1-N1 122.65(10)

C23-W1-N1 154.02(10)

O2-W1-N1 82.92(8)

O1-W1-N1 81.68(8)

C21-W1-C22 41.79(11)

C23-W1-C22 41.52(11)

O2-W1-C22 99.81(9)

O1-W1-C22 102.70(8)

N1-W1-C22 164.43(10)

C23-W2-O1 102.23(16)

C23-W2-O2 92.69(15)

O1-W2-O2 164.89(18)

C23-W2-N1 170.7(3)

O1-W2-N1 84.13(12)

O2-W2-N1 80.77(12)

C23-W2-C22 37.41(14)

O1-W2-C22 99.12(15)

O2-W2-C22 91.27(16)

N1-W2-C22 135.5(3)

C23-W2-C21 72.92(18)

O1-W2-C21 94.62(19)

O2-W2-C21 87.46(18)

N1-W2-C21 100.1(2)

C22-W2-C21 35.55(12)

C1-O1-W2 139.76(18)

C1-O1-W1 137.67(15)

W2-O1-W1 16.71(16)

C11-O2-W1 132.08(16)

C11-O2-W2 139.98(18)

W1-O2-W2 16.54(14)

C3-N1-C13 117.2(2)

C3-N1-W1 129.19(16)

C13-N1-W1 113.54(15)

C3-N1-W2 116.6(2)

C13-N1-W2 125.63(19)

W1-N1-W2 15.89(14)

O1-C1-C2 112.3(2)

O1-C1-C8 103.1(2)

C2-C1-C8 112.9(2)

O1-C1-C9 109.9(2)

C2-C1-C9 109.9(2)

C8-C1-C9 108.5(2)

C7-C2-C3 119.1(2)

C7-C2-C1 121.9(2)

C3-C2-C1 119.0(2)

C4-C3-C2 117.9(2)

C4-C3-N1 119.2(2)

C2-C3-N1 122.8(2)

C5-C4-C3 121.7(2)

C4-C5-C6 120.8(2)

C7-C6-C5 117.9(2)

C7-C6-C10 121.2(2)

C5-C6-C10 120.9(2)

C6-C7-C2 122.6(2)

F2-C8-F3 106.7(2)

F2-C8-F1 106.7(2)

F3-C8-F1 107.3(2)

F2-C8-C1 111.6(2)

F3-C8-C1 114.6(2)

F1-C8-C1 109.6(2)

F6-C9-F4 107.5(2)

F6-C9-F5 107.5(2)

F4-C9-F5 107.3(2)

F6-C9-C1 111.9(2)

F4-C9-C1 110.4(2)

F5-C9-C1 112.0(2)

O2-C11-C12 114.2(2)

O2-C11-C19 105.9(2)

C12-C11-C19 110.0(2)

O2-C11-C18 104.2(2)

C12-C11-C18 112.8(2)

C19-C11-C18 109.3(2)

C17-C12-C13 119.2(2)

C17-C12-C11 121.3(2)

C13-C12-C11 119.6(2)

C14-C13-C12 117.8(2)

C14-C13-N1 118.4(2)

C12-C13-N1 123.7(2)

C15-C14-C13 121.8(2)

C14-C15-C16 121.1(2)

C17-C16-C15 117.3(2)

C17-C16-C20 121.0(2)

C15-C16-C20 121.7(3)

C16-C17-C12 122.9(2)

F8-C18-F7 107.1(2)

F8-C18-F9 106.4(2)

F7-C18-F9 107.4(2)

F8-C18-C11 111.3(2)

F7-C18-C11 110.2(2)

F9-C18-C11 114.1(2)

F11-C19-F12 107.3(2)

F11-C19-F10 107.1(2)

F12-C19-F10 106.9(3)

F11-C19-C11 112.7(2)

F12-C19-C11 111.9(2)

F10-C19-C11 110.5(2)

C22-C21-C24 130.9(2)

C22-C21-W1 78.78(16)

C24-C21-W1 150.2(2)

C22-C21-W2 72.07(17)

346


C24-C21-W2 156.6(2)

W1-C21-W2 7.04(7)

C23-C22-C21 120.0(2)

C23-C22-C28 119.2(3)

C21-C22-C28 120.8(3)

C23-C22-W1 60.53(15)

C21-C22-W1 59.43(14)

C28-C22-W1 178.6(2)

C23-C22-W2 47.66(18)

C21-C22-W2 72.38(19)

C28-C22-W2 166.8(2)

W1-C22-W2 13.10(11)

C22-C23-C29 133.4(3)

C22-C23-W2 94.9(3)

C29-C23-W2 131.7(3)

C22-C23-W1 77.96(17)

C29-C23-W1 148.6(2)

W2-C23-W1 17.25(17)

C21-C24-C27 112.6(3)

C21-C24-C25 106.9(2)

C27-C24-C25 108.0(2)

C21-C24-C26 109.1(2)

C27-C24-C26 110.7(2)

C25-C24-C26 109.4(3)

C23-C29-C30 111.6(3)

C23-C29-C31 111.2(3)

C30-C29-C31 111.5(3)

C23-C29-C32 104.2(3)

C30-C29-C32 109.2(3)

C31-C29-C32 108.8(3)


Table A- 46. Anisotropic displacement parameters (Å2x 103) for 14. The anisotropic displacement factor exponent takes the form: -2π2[h2 a*2U11 + ... + 2 h k a* b* U12 ]

U11 U22 U33 U23 U13 U12

W1 14(1) 13(1) 18(1) 2(1) 4(1) -1(1)

F1 39(1) 37(1) 21(1) -6(1) 7(1) 1(1)

F2 41(1) 20(1) 48(1) -6(1) 23(1) 1(1)

F3 28(1) 31(1) 43(1) -3(1) 21(1) 1(1)

F4 30(1) 40(1) 20(1) 5(1) 4(1) 7(1)

F5 33(1) 24(1) 41(1) 12(1) 7(1) 9(1)

F6 18(1) 39(1) 34(1) 10(1) 2(1) -3(1)

F7 35(1) 42(1) 47(1) 8(1) 16(1) -12(1)

F8 22(1) 46(1) 59(1) -9(1) 13(1) -15(1)

F9 23(1) 53(1) 66(1) -14(1) 23(1) -4(1)

F10 32(1) 31(1) 34(1) 9(1) 4(1) 3(1)

F11 32(1) 26(1) 77(1) 3(1) 18(1) 12(1)

F12 30(1) 41(1) 70(1) 12(1) -19(1) -3(1)

O1 18(1) 18(1) 28(1) -2(1) 9(1) -1(1)

O2 16(1) 19(1) 32(1) -1(1) 4(1) 0(1)

N1 15(1) 15(1) 24(1) 0(1) 8(1) 0(1)

C1 16(1) 18(1) 22(1) 1(1) 6(1) 1(1)

C2 17(1) 18(1) 16(1) 1(1) 1(1) 0(1)

C3 16(1) 18(1) 20(1) 1(1) 3(1) -2(1)

C4 20(1) 19(1) 28(1) 1(1) 7(1) 2(1)

C5 26(1) 17(1) 26(1) 4(1) 5(1) -1(1)

C6 21(1) 23(1) 21(1) 3(1) 4(1) -5(1)

C7 20(1) 23(1) 19(1) 0(1) 5(1) 0(1)

C8 25(1) 21(2) 29(1) -1(1) 10(1) 2(1)

C9 21(1) 22(1) 27(1) 7(1) 6(1) 3(1)

C10 35(2) 27(2) 32(1) 5(1) 15(1) -4(1)

C11 16(1) 18(1) 34(1) 0(1) 8(1) 0(1)

C12 17(1) 17(1) 30(1) 2(1) 7(1) 0(1)

C13 18(1) 14(1) 25(1) 3(1) 7(1) 0(1)

C14 17(1) 21(1) 28(1) 2(1) 7(1) -1(1)

C15 24(1) 24(1) 26(1) 0(1) 5(1) -4(1)

347


C16 30(1) 21(1) 27(1) 2(1) 11(1) 0(1)

C17 22(1) 23(1) 33(1) 2(1) 14(1) 1(1)

C18 19(1) 34(2) 47(2) -3(1) 13(1) -5(1)

C19 17(1) 25(2) 47(2) 2(1) 1(1) 2(1)

C20 40(2) 36(2) 29(1) -3(1) 14(1) 0(1)

C21 23(1) 21(1) 30(1) 6(1) 11(1) 5(1)

C22 21(1) 25(2) 41(2) 3(1) 15(1) 3(1)

C23 19(1) 24(1) 32(1) -3(1) 8(1) -2(1)

C24 31(2) 31(2) 31(1) 11(1) 14(1) 9(1)

C25 40(2) 43(2) 27(1) 7(1) 9(1) 7(1)

C26 36(2) 38(2) 34(2) 13(1) 13(1) 10(1)

C27 45(2) 46(2) 43(2) 14(2) 24(2) 6(2)

C28 35(2) 22(2) 53(2) -1(1) 21(1) -2(1)

C29 30(2) 39(2) 34(2) -7(1) 2(1) -4(1)

C30 65(3) 71(3) 39(2) -23(2) 10(2) 3(2)

C31 36(2) 68(3) 59(2) -12(2) 0(2) -17(2)

C32 43(2) 72(3) 32(2) 4(2) -4(1) -7(2)




detector.

348

Raw data frames were read by program SAINT1 and integrated using 3D profiling

algorithms. The resulting data were reduced to produce hkl reflections and their

intensities and estimated standard deviations. The data were corrected for Lorentz and

polarization effects and numerical absorption corrections were applied based on





riding on their parent atoms. The C30-C31 unit is disordered and was refined against

the minor part C30’-C31’ with their site occupation factors dependently refined. In the

final cycle of refinement, 7274 reflections (of which 6082 are observed with I > 2(I))

were used to refine 446 parameters and the resulting R1, wR2 and S (goodness of fit)

were 2.09%, 4.48% and 0.962, respectively. The refinement was carried out by

minimizing the wR2 function using F2 rather than F values. R1 is calculated to provide a

reference to the conventional R value but its function is not minimized.









Space group P21/c


b = 9.2537(5) Å = 112.5630(10)°.

c = 18.9077(10) Å = 90°.

Volume 3168.0(3) Å3

Z 4



349


F(000) 1744



Index ranges -25≤h≤25, -11≤k≤12, -24≤l≤24












wR2 = [w(Fo2 - Fc

2)2] / wFo22]]1/2

S = [w(Fo2 - Fc

2)2] / (n-p)]1/2

w= 1/[2(Fo2)+(m*p)

2+n*p], p = [max(Fo


Table A- 48. Atomic coordinates ( x 104) and equivalent isotropic displacement

parameters (Å2x 103) for 15. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor.

Atom X Y Z U(eq)

W1 2478(1) 775(1) 2714(1) 13(1)

F1 826(1) -2223(2) 1992(1) 26(1)

F2 146(1) -423(2) 2012(1) 27(1)

F3 210(1) -2259(2) 2733(1) 25(1)

F4 388(1) 689(2) 3386(1) 27(1)

F5 921(1) -1027(2) 4164(1) 26(1)

F6 1521(1) 900(2) 4142(1) 26(1)

F7 3997(1) 4513(2) 3826(1) 21(1)

F8 4397(1) 3594(2) 3016(1) 19(1)

F9 5088(1) 3576(2) 4214(1) 21(1)

F10 4774(1) 777(2) 3183(1) 24(1)

F11 5187(1) 742(2) 4415(1) 20(1)

F12 4257(1) -577(1) 3754(1) 20(1)

O1 1499(1) 397(2) 2734(1) 16(1)

O2 3400(1) 1895(2) 3117(1) 14(1)

N1 2833(1) 166(2) 3826(1) 13(1)

C1 1281(1) -717(3) 3094(2) 16(1)

C2 1898(1) -1802(3) 3509(2) 15(1)

C3 2617(1) -1283(3) 3907(1) 13(1)

C4 3160(1) -2263(3) 4349(2) 17(1)

C5 3002(2) -3715(3) 4362(2) 17(1)

C6 2306(2) -4261(3) 3926(2) 19(1)

C7 1758(2) -3286(3) 3525(2) 18(1)

C8 608(2) -1416(3) 2452(2) 20(1)

C9 1020(1) -31(3) 3699(2) 18(1)

C10 2161(2) -5868(3) 3853(2) 27(1)

C11 4030(1) 1943(2) 3777(1) 12(1)

350


C12 3863(1) 1823(2) 4503(1) 12(1)

C13 3290(1) 903(3) 4496(1) 13(1)

C14 3168(1) 747(3) 5178(2) 17(1)

C15 3597(2) 1462(3) 5840(2) 18(1)

C16 4167(2) 2375(3) 5856(2) 18(1)

C17 4287(1) 2537(3) 5181(1) 16(1)

C18 4387(1) 3415(3) 3714(2) 16(1)

C19 4572(1) 713(3) 3786(1) 15(1)

C20 4659(2) 3116(3) 6584(2) 29(1)

C21 2530(2) -436(3) 1918(2) 18(1)

C22 2220(1) 869(3) 1500(2) 19(1)

C23 2092(1) 2132(3) 1906(2) 18(1)

C24 2782(2) -1836(3) 1678(2) 22(1)

C25 2168(2) -2544(3) 992(2) 30(1)

C26 3464(2) -1553(3) 1488(2) 29(1)

C27 2998(2) -2871(3) 2360(2) 26(1)

C28 1984(2) 1014(3) 639(2) 28(1)

C29 1148(2) 698(4) 215(2) 41(1)

C30 600(3) 1599(6) 545(3) 29(1)

C31 644(3) 3253(5) 506(3) 30(1)

C30' 664(5) 1767(9) 101(5) 30(2)

C31' 532(4) 2126(9) 823(5) 24(2)

C32 1017(2) 3825(5) 1272(2) 53(1)

C33 1855(2) 3609(3) 1585(2) 33(1)


W1-C23 1.897(3)

W1-C21 1.911(3)

W1-O1 1.9648(17)

W1-O2 1.9664(16)

W1-N1 2.023(2)

W1-C22 2.156(3)

F1-C8 1.336(3)

F2-C8 1.335(3)

F3-C8 1.349(3)

F4-C9 1.330(3)

F5-C9 1.339(3)

F6-C9 1.332(3)

F7-C18 1.337(3)

F8-C18 1.337(3)

F9-C18 1.345(3)

F10-C19 1.343(3)

F11-C19 1.331(3)

F12-C19 1.335(3)

O1-C1 1.390(3)

O2-C11 1.379(3)

N1-C13 1.416(3)

N1-C3 1.432(3)

C1-C2 1.536(4)

C1-C8 1.550(4)

C1-C9 1.558(3)

C2-C7 1.403(3)

C2-C3 1.403(3)

C3-C4 1.404(3)

C4-C5 1.381(4)

C5-C6 1.390(4)

C6-C7 1.386(4)

C6-C10 1.511(4)

C11-C12 1.532(3)

C11-C19 1.553(3)

C11-C18 1.557(3)

C12-C17 1.398(3)

C12-C13 1.405(3)

C13-C14 1.406(3)

C14-C15 1.379(4)

C15-C16 1.391(4)

C16-C17 1.392(3)

C16-C20 1.509(4)

C21-C22 1.443(4)

C21-C24 1.516(4)

C22-C23 1.473(4)

C22-C28 1.517(4)

C23-C33 1.496(4)

C24-C27 1.530(4)

C24-C26 1.536(4)

C24-C25 1.538(4)

C28-C29 1.550(4)

C29-C30' 1.330(9)

351

Table A- 50. Continued. Bond Length Bond Length C29-C30 1.659(6)

C30-C31 1.536(7)

C31-C32 1.449(6)

C30'-C31' 1.521(12)

C31'-C32 1.865(9)

C32-C33 1.531(4)



C23-W1-C21 83.04(11)

C23-W1-O1 92.39(9)

C21-W1-O1 104.95(9)

C23-W1-O2 89.20(9)

C21-W1-O2 107.16(9)

O1-W1-O2 147.80(7)

C23-W1-N1 153.22(10)

C21-W1-N1 123.66(10)

O1-W1-N1 83.14(8)

O2-W1-N1 81.16(7)

C23-W1-C22 42.03(11)

C21-W1-C22 41.01(10)

O1-W1-C22 101.27(9)

O2-W1-C22 101.29(8)

N1-W1-C22 164.62(9)

C1-O1-W1 128.81(15)

C11-O2-W1 137.59(14)

C13-N1-C3 117.82(19)

C13-N1-W1 130.02(15)

C3-N1-W1 111.98(15)

O1-C1-C2 113.9(2)

O1-C1-C8 104.8(2)

C2-C1-C8 113.2(2)

O1-C1-C9 107.9(2)

C2-C1-C9 107.9(2)

C8-C1-C9 108.9(2)

C7-C2-C3 119.2(2)

C7-C2-C1 121.9(2)

C3-C2-C1 118.8(2)

C2-C3-C4 118.3(2)

C2-C3-N1 122.7(2)

C4-C3-N1 118.7(2)

C5-C4-C3 121.0(2)

C4-C5-C6 121.2(2)

C7-C6-C5 117.9(2)

C7-C6-C10 120.7(3)

C5-C6-C10 121.3(2)

C6-C7-C2 122.1(3)

F2-C8-F1 106.7(2)

F2-C8-F3 106.7(2)

F1-C8-F3 108.2(2)

F2-C8-C1 111.8(2)

F1-C8-C1 110.7(2)

F3-C8-C1 112.4(2)

F4-C9-F6 107.0(2)

F4-C9-F5 106.9(2)

F6-C9-F5 106.9(2)

F4-C9-C1 112.9(2)

F6-C9-C1 110.8(2)

F5-C9-C1 111.9(2)

O2-C11-C12 112.54(19)

O2-C11-C19 110.95(19)

C12-C11-C19 108.54(19)

O2-C11-C18 103.38(19)

C12-C11-C18 112.90(19)

C19-C11-C18 108.41(19)

C17-C12-C13 119.1(2)

C17-C12-C11 122.1(2)

C13-C12-C11 118.7(2)

C12-C13-C14 118.1(2)

C12-C13-N1 122.0(2)

C14-C13-N1 120.0(2)

C15-C14-C13 121.6(2)

C14-C15-C16 121.1(2)

C15-C16-C17 117.5(2)

C15-C16-C20 121.6(2)

C17-C16-C20 120.8(2)

C16-C17-C12 122.6(2)

F8-C18-F7 106.8(2)

F8-C18-F9 106.37(19)

F7-C18-F9 107.2(2)

F8-C18-C11 111.2(2)

F7-C18-C11 110.6(2)

F9-C18-C11 114.3(2)

F11-C19-F12 107.6(2)

F11-C19-F10 107.29(19)

F12-C19-F10 106.39(19)

F11-C19-C11 112.2(2)

F12-C19-C11 110.62(19)

F10-C19-C11 112.4(2)

C22-C21-C24 131.9(2)

C22-C21-W1 78.64(15)

C24-C21-W1 149.1(2)

C21-C22-C23 119.9(2)

C21-C22-C28 123.6(2)

C23-C22-C28 116.5(2)

C21-C22-W1 60.35(14)

C23-C22-W1 59.54(13)

C28-C22-W1 175.2(2)

C22-C23-C33 127.0(2)

352

Table A- 51. Continued. Bond Angle Bond Angle C22-C23-W1 78.44(15)

C33-C23-W1 154.0(2)

C21-C24-C27 107.5(2)

C21-C24-C26 109.7(2)

C27-C24-C26 108.6(2)

C21-C24-C25 112.2(2)

C27-C24-C25 108.6(2)

C26-C24-C25 110.2(2)

C22-C28-C29 111.4(2)

C30'-C29-C28 119.4(5)

C30'-C29-C30 33.1(4)

C28-C29-C30 114.8(3)

C31-C30-C29 115.3(4)

C32-C31-C30 109.4(4)

C29-C30'-C31' 112.0(7)

C30'-C31'-C32 111.1(5)

C31-C32-C33 113.2(3)

C31-C32-C31' 42.5(3)

C33-C32-C31' 110.5(3)

C23-C33-C32 113.3(3)




U11 U22 U33 U23 U13 U12

W1 15(1) 11(1) 12(1) 1(1) 5(1) -1(1)

F1 29(1) 26(1) 23(1) -8(1) 10(1) -6(1)

F2 19(1) 26(1) 27(1) 3(1) 1(1) -1(1)

F3 22(1) 22(1) 32(1) -1(1) 11(1) -8(1)

F4 23(1) 28(1) 31(1) 4(1) 11(1) 12(1)

F5 34(1) 23(1) 30(1) 7(1) 22(1) 5(1)

F6 25(1) 24(1) 31(1) -12(1) 13(1) -4(1)

F7 31(1) 12(1) 26(1) 1(1) 17(1) 1(1)

F8 29(1) 17(1) 16(1) 0(1) 14(1) -6(1)

F9 20(1) 20(1) 21(1) -1(1) 5(1) -8(1)

F10 34(1) 25(1) 20(1) 4(1) 19(1) 8(1)

F11 18(1) 21(1) 20(1) 0(1) 5(1) 3(1)

F12 24(1) 10(1) 28(1) -2(1) 12(1) 0(1)

O1 16(1) 14(1) 18(1) 5(1) 6(1) 0(1)

O2 16(1) 14(1) 10(1) 1(1) 5(1) -3(1)

N1 17(1) 10(1) 11(1) 2(1) 5(1) -2(1)

C1 17(1) 12(1) 20(1) -1(1) 8(1) -2(1)

C2 18(1) 13(1) 17(1) 2(1) 10(1) 2(1)

C3 18(1) 11(1) 12(1) 0(1) 9(1) 1(1)

C4 17(1) 20(1) 16(1) 3(1) 8(1) 4(1)

C5 25(2) 14(1) 17(1) 5(1) 13(1) 8(1)

C6 30(2) 12(1) 24(1) 1(1) 18(1) 1(1)

C7 22(1) 14(1) 23(2) -1(1) 13(1) -1(1)

C8 19(1) 18(1) 24(2) 2(1) 7(1) -2(1)

C9 18(1) 15(1) 22(2) 2(1) 9(1) 2(1)

C10 40(2) 12(1) 35(2) 1(1) 22(2) 1(1)

C11 13(1) 10(1) 12(1) -1(1) 5(1) 0(1)

C12 16(1) 9(1) 12(1) 0(1) 6(1) 3(1)

C13 16(1) 10(1) 13(1) 2(1) 6(1) 4(1)

C14 18(1) 16(1) 18(1) 4(1) 10(1) 4(1)

C15 27(2) 18(1) 14(1) 3(1) 12(1) 5(1)

C16 30(2) 11(1) 14(1) -1(1) 9(1) 4(1)

C17 23(1) 8(1) 16(1) 1(1) 7(1) 1(1)

C18 20(1) 14(1) 14(1) 0(1) 8(1) -2(1)

C19 19(1) 14(1) 14(1) 1(1) 9(1) -1(1)

C20 50(2) 20(2) 16(2) -4(1) 12(2) -5(1)

353


C21 21(1) 19(1) 14(1) -3(1) 8(1) -6(1)

C22 17(1) 25(1) 13(1) 4(1) 4(1) -7(1)

C23 15(1) 20(1) 18(1) 4(1) 6(1) -2(1)

C24 26(2) 22(1) 19(2) -7(1) 11(1) -3(1)

C25 35(2) 30(2) 28(2) -14(1) 14(2) -9(1)

C26 30(2) 36(2) 26(2) -6(1) 15(1) -4(1)

C27 37(2) 20(1) 28(2) -6(1) 19(2) -2(1)

C28 28(2) 40(2) 14(1) 4(1) 4(1) -10(1)

C29 32(2) 56(2) 23(2) 4(2) -4(1) -16(2)

C32 40(2) 87(3) 31(2) 10(2) 14(2) 37(2)

C33 38(2) 30(2) 39(2) 20(2) 24(2) 12(1)



SMART diffractometer using MoK radiation ( = 0.71073 Å) and an APEXII CCD area





354

indexed and measured faces. The structure was solved and refined in SHELXTL6.1,

using full-matrix least-squares refinement. The non-H atoms were refined with

anisotropic thermal parameters and all of the H atoms were calculated in idealized

positions and refined riding on their parent atoms. A disorder between H4a and a small

percentage of Br on C4 was identified with the final refinement yielding 3% of Br and

97% of the proton. The Br atom was refined with several site occupation factors until an

acceptable value was reached; which was 3%. In the final cycle of refinement, 5441

reflections (of which 4758 are observed with I > 2(I)) were used to refine 403

parameters and the resulting R1, wR2 and S (goodness of fit) were 2.51%, 4.76% and

1.050, respectively. The refinement was carried out by minimizing the wR2 function

using F2 rather than F values. R1 is calculated to provide a reference to the

conventional R value but its function is not minimized. SHELXTL6 (2000). Bruker-AXS,

Madison, Wisconsin, USA.



Empirical formula C27H26.94Br0.03 F12NO3W




Crystal system Triclinic

Space group P-1

Unit cell dimensions a = 8.5483(3) Å = 86.891(2)°.

b = 9.4574(3) Å = 82.183(2)°.

c = 19.5076(6) Å = 70.699(2)°.

Volume 1474.54(8) Å3

Z 2



F(000) 806



Index ranges -10≤h≤10, -11≤k≤11, -23≤l≤23





355









R1 = (||Fo| - |Fc||) / |Fo| wR2 = [w(Fo2 - Fc

2)2] / wFo22]]1/2

S = [w(Fo2 - Fc

2)2] / (n-p)]1/2 w= 1/[2(Fo2)+(m*p)

2+n*p], p = [max(Fo



Atom X Y Z U(eq)

W1 3609(1) 1736(1) 2549(1) 16(1)

F1 5880(2) 4612(2) 2861(1) 30(1)

F2 7688(2) 2958(2) 3406(1) 27(1)

F3 6058(2) 4965(2) 3925(1) 30(1)

F4 6595(2) 982(2) 4222(1) 29(1)

F5 5490(2) 2925(2) 4863(1) 31(1)

F6 3976(2) 1660(2) 4595(1) 31(1)

F7 1602(3) 3244(2) 8(1) 28(1)

F8 2913(3) 1095(2) 423(1) 31(1)

F9 4092(2) 2785(2) 270(1) 29(1)

F10 -894(2) 4073(2) 1021(1) 27(1)

F11 17(3) 1759(2) 1329(1) 35(1)

F12 -415(2) 3500(2) 2066(1) 28(1)

O1 5040(3) 2101(3) 3171(1) 19(1)

O2 3011(3) 2015(3) 1620(1) 20(1)

O3 5245(3) -24(3) 2314(1) 18(1)

N1 2585(3) 3959(3) 2559(2) 17(1)

Br -970(20) 5834(19) 2883(9) 50(4)

C1 4814(4) 3133(4) 3689(2) 18(1)

C2 3058(4) 4308(4) 3776(2) 17(1)

C3 2080(4) 4656(4) 3227(2) 17(1)

C4 460(4) 5697(4) 3337(2) 20(1)

C5 -103(4) 6470(4) 3956(2) 22(1)

C6 889(4) 6213(4) 4487(2) 19(1)

C7 2446(4) 5116(4) 4387(2) 18(1)

C8 6117(4) 3925(4) 3474(2) 20(1)

C9 5219(4) 2179(4) 4348(2) 22(1)

C10 309(4) 7124(4) 5144(2) 24(1)

C11 1969(4) 3106(4) 1228(2) 17(1)

C12 2072(4) 4648(4) 1346(2) 17(1)

C13 2442(4) 4975(4) 1990(2) 16(1)

C14 2661(4) 6366(4) 2059(2) 21(1)

C15 2447(4) 7408(4) 1526(2) 21(1)

C16 2010(4) 7124(4) 898(2) 20(1)

C17 1849(4) 5732(4) 826(2) 19(1)

C18 2638(4) 2562(4) 475(2) 23(1)

356


C19 150(4) 3108(4) 1412(2) 21(1)

C20 1761(5) 8246(4) 318(2) 27(1)

C21 6921(4) -850(4) 1986(2) 23(1)

C22 7123(5) -172(5) 1275(2) 42(1)

C23 7040(5) -2471(5) 1966(3) 48(1)

C24 8137(4) -623(5) 2438(2) 35(1)

C25 1954(4) 1209(4) 3141(2) 20(1)

C26 1779(5) -170(4) 3514(2) 30(1)

C27 3404(5) -1428(4) 3571(2) 34(1)


W1-O3 1.819(2)

W1-C25 1.882(4)

W1-O2 1.931(2)

W1-O1 1.953(2)

W1-N1 1.993(3)

F1-C8 1.337(4)

F2-C8 1.345(4)

F3-C8 1.339(4)

F4-C9 1.340(4)

F5-C9 1.345(4)

F6-C9 1.335(4)

F7-C18 1.344(4)

F8-C18 1.336(4)

F9-C18 1.333(4)

F10-C19 1.335(4)

F11-C19 1.338(4)

F12-C19 1.328(4)

O1-C1 1.392(4)

O2-C11 1.391(4)

O3-C21 1.462(4)

N1-C13 1.418(5)

N1-C3 1.440(4)

Br-C4 1.571(16)

C1-C8 1.539(5)

C1-C2 1.539(4)

C1-C9 1.541(5)

C2-C7 1.395(5)

C2-C3 1.404(5)

C3-C4 1.405(4)

C4-C5 1.388(5)

C5-C6 1.389(5)

C6-C7 1.387(5)

C6-C10 1.514(5)

C11-C12 1.522(5)

C11-C19 1.547(5)

C11-C18 1.552(5)

C12-C17 1.387(5)

C12-C13 1.411(5)

C13-C14 1.404(5)

C14-C15 1.381(5)

C15-C16 1.392(5)

C16-C17 1.384(5)

C16-C20 1.496(5)

C21-C23 1.505(6)

C21-C22 1.509(6)

C21-C24 1.523(5)

C25-C26 1.499(5)

C26-C27 1.515(5)


Table A- 54. Bond angles [°] for 16. Bond Angle Bond Angle O2-C11-C12 111.2(3)

O2-C11-C19 109.6(3)

C12-C11-C19 110.3(3)

O2-C11-C18 103.1(3)

C12-C11-C18 112.4(3)

C19-C11-C18 110.1(3)

C17-C12-C13 119.1(3)

C17-C12-C11 121.4(3)

C13-C12-C11 119.5(3)

C14-C13-C12 117.7(3)

C14-C13-N1 120.0(3)

C12-C13-N1 122.3(3)

C15-C14-C13 121.3(3)

C14-C15-C16 121.5(3)

C17-C16-C15 116.8(3)

C17-C16-C20 121.1(3)

C15-C16-C20 122.1(3)

C16-C17-C12 123.5(3)

F9-C18-F8 106.8(3)

F9-C18-F7 107.1(3)

F8-C18-F7 106.3(3)

F9-C18-C11 110.8(3)

F8-C18-C11 111.3(3)

F7-C18-C11 114.1(3)

357

Table A- 56. Continued. Bond Angle Bond Angle F12-C19-F10 106.9(3)

F12-C19-F11 107.5(3)

F10-C19-F11 107.0(3)

F12-C19-C11 110.9(3)

F10-C19-C11 112.2(3)

F11-C19-C11 112.0(3)

O3-C21-C23 107.3(3)

O3-C21-C22 107.0(3)

C23-C21-C22 112.9(3)

O3-C21-C24 106.4(3)

C23-C21-C24 111.6(3)

C22-C21-C24 111.3(4)

C26-C25-W1 137.2(3)

C25-C26-C27 115.1(3)




U11 U22 U33 U23 U13 U12

W1 15(1) 16(1) 15(1) -1(1) 0(1) -2(1)

F1 25(1) 39(1) 27(1) 10(1) -1(1) -13(1)

F2 13(1) 34(1) 32(1) -5(1) 1(1) -4(1)

F3 25(1) 32(1) 36(2) -12(1) 0(1) -13(1)

F4 24(1) 28(1) 26(1) 3(1) -6(1) 4(1)

F5 32(1) 38(1) 20(1) -2(1) -11(1) -4(1)

F6 25(1) 37(1) 31(1) 14(1) 0(1) -12(1)

F7 34(1) 34(1) 16(1) 0(1) -8(1) -9(1)

F8 48(1) 22(1) 22(1) -6(1) -4(1) -10(1)

F9 27(1) 36(1) 21(1) -6(1) 6(1) -9(1)

F10 20(1) 34(1) 26(1) 5(1) -9(1) -8(1)

F11 33(1) 28(1) 52(2) 0(1) -6(1) -19(1)

F12 20(1) 41(1) 19(1) -1(1) 4(1) -10(1)

O1 17(1) 20(1) 16(1) -4(1) -1(1) 0(1)

O2 20(1) 18(1) 18(1) -3(1) -3(1) -2(1)

O3 18(1) 18(1) 14(1) 0(1) 2(1) -3(1)

N1 18(1) 19(2) 11(2) -3(1) -4(1) -2(1)

C1 15(2) 20(2) 18(2) -2(2) 0(2) -4(2)

C2 13(2) 19(2) 16(2) -1(2) 0(2) -4(1)

C3 18(2) 16(2) 16(2) -2(2) 0(2) -5(1)

C4 21(2) 17(2) 20(2) -3(2) 3(2) -4(2)

C5 16(2) 23(2) 23(2) -2(2) 0(2) -2(2)

C6 17(2) 20(2) 20(2) -4(2) 5(2) -8(2)

C7 19(2) 23(2) 14(2) 1(2) -4(2) -10(2)

C8 16(2) 24(2) 19(2) 0(2) 2(2) -5(2)

C9 18(2) 26(2) 20(2) 0(2) -2(2) -4(2)

C10 22(2) 27(2) 22(2) -6(2) 0(2) -6(2)

C11 18(2) 17(2) 13(2) 3(2) -2(2) -4(2)

C12 14(2) 20(2) 15(2) 0(2) 0(2) -6(1)

C13 9(2) 18(2) 16(2) -2(2) 1(1) 0(1)

C14 17(2) 21(2) 23(2) -7(2) -3(2) -4(2)

C15 20(2) 16(2) 26(2) 1(2) -3(2) -5(2)

C16 15(2) 22(2) 21(2) 4(2) -2(2) -5(2)

C17 14(2) 25(2) 16(2) 0(2) -1(2) -6(2)

C18 26(2) 24(2) 19(2) -1(2) -2(2) -9(2)

C19 24(2) 20(2) 20(2) 0(2) -4(2) -10(2)

C20 30(2) 25(2) 26(2) 5(2) -4(2) -10(2)

C21 16(2) 26(2) 20(2) -6(2) 4(2) 2(2)

C22 30(2) 60(3) 26(3) -2(2) 9(2) -5(2)

358


C23 31(2) 28(3) 77(4) -17(2) 4(2) -2(2)

C24 20(2) 39(3) 38(3) -11(2) -3(2) 3(2)

C25 21(2) 25(2) 10(2) 0(2) 3(2) -6(2)

C26 31(2) 30(2) 27(3) -1(2) 7(2) -12(2)

C27 46(2) 30(2) 31(3) 12(2) -5(2) -23(2)








indexed and measured faces. The structure was solved and refined in SHELXTL6.1,

using full-matrix least-squares refinement. The non-H atoms were refined with

anisotropic thermal parameters and all of the H atoms were calculated in idealized

359

positions and refined riding on their parent atoms. In the final cycle of refinement, 5714

reflections (of which 4559 are observed with I > 2 (I)) were used to refine 363

parameters and the resulting R1, wR2 and S (goodness of fit) were 1.87%, 3.38% and

0.901, respectively. The highest residual electron density peak is within 1 Å of W1 and

thus attributed to its anisotropy. The refinement was carried out by minimizing the wR2

function using F2 rather than F values. R1 is calculated to provide a reference to the

conventional R value but its function is not minimized. SHELXTL6 (2008). Bruker-AXS,

Madison, Wisconsin, USA.

Table A- 56 Crystal data and structure refinement for 20. Item Value


Empirical formula C23H19F12NO3W





Space group P21/c


b = 16.9746(9) Å = 112.895(1)°.

c = 13.2038(7) Å = 90°.

Volume 2489.8(2) Å3

Z 4



F(000) 1480



Index ranges -14≤h≤15, -22≤k≤22, -17≤l≤17












R1 = (||Fo| - |Fc||) / |Fo| wR2 = [w(Fo2 - Fc

2)2] / wFo22]]1/2

S = [w(Fo2 - Fc

2)2] / (n-p)]1/2 w= 1/[2(Fo2)+(m*p)

2+n*p], p = [max(Fo


360


Atom X Y Z U(eq)

W1 480(1) 3415(1) 5351(1) 13(1)

F1 -589(1) 2776(1) 7359(1) 24(1)

F2 -2463(1) 2603(1) 7013(1) 30(1)

F3 -1757(2) 3775(1) 7087(1) 30(1)

F4 -3435(1) 3292(1) 3771(1) 23(1)

F5 -3028(1) 4199(1) 4992(1) 20(1)

F6 -4058(1) 3193(1) 5091(1) 24(1)

F7 4190(1) 3026(1) 7507(1) 29(1)

F8 4996(1) 2374(1) 6565(1) 29(1)

F9 4234(1) 3521(1) 6027(1) 25(1)

F10 1699(2) 1921(1) 4099(1) 32(1)

F11 3487(2) 1470(1) 4926(1) 31(1)

F12 3223(2) 2618(1) 4189(1) 30(1)

O1 -1079(1) 3459(1) 5339(1) 15(1)

O2 2042(2) 3116(1) 5534(2) 16(1)

O3 132(2) 3908(1) 4142(2) 21(1)

N1 303(2) 2258(1) 5623(2) 14(1)

C1 -1942(2) 2999(2) 5524(2) 13(1)

C2 -1897(2) 2152(2) 5159(2) 13(1)

C3 -816(2) 1836(2) 5179(2) 13(1)

C4 -839(2) 1080(2) 4763(2) 16(1)

C5 -1874(2) 633(2) 4403(2) 17(1)

C6 -2942(2) 923(2) 4425(2) 16(1)

C7 -2935(2) 1690(2) 4796(2) 16(1)

C8 -1692(2) 3038(2) 6761(2) 19(1)

C9 -3139(2) 3419(2) 4833(2) 18(1)

C10 -4086(2) 445(2) 4046(2) 22(1)

C11 2834(2) 2479(2) 5827(2) 14(1)

C12 2473(2) 1868(1) 6485(2) 11(1)

C13 1275(2) 1804(1) 6384(2) 12(1)

C14 1031(2) 1279(2) 7091(2) 15(1)

C15 1904(2) 801(2) 7803(2) 14(1)

C16 3081(2) 821(2) 7858(2) 13(1)

C17 3344(2) 1364(1) 7202(2) 13(1)

C18 4085(2) 2853(2) 6494(2) 20(1)

C19 2818(3) 2122(2) 4746(2) 21(1)

C20 4035(2) 288(2) 8616(2) 20(1)

C21 1128(2) 4226(2) 6656(2) 19(1)

C22 2203(3) 4744(2) 6772(3) 30(1)

C23 2564(3) 5280(2) 7769(2) 32(1)


W1-O3 1.7040(18)

W1-O2 1.8737(16)

W1-O1 1.8753(16)

W1-N1 2.022(2)

W1-C21 2.105(3)

F1-C8 1.332(3)

F2-C8 1.327(3)

F3-C8 1.334(3)

F4-C9 1.323(3)

F5-C9 1.340(3)

F6-C9 1.336(3)

F7-C18 1.326(3)

F8-C18 1.340(3)

F9-C18 1.336(3)

361

Table A- 60. Continued. Bond Length Bond Length F10-C19 1.330(3)

F11-C19 1.335(3)

F12-C19 1.330(3)

O1-C1 1.397(3)

O2-C11 1.394(3)

N1-C3 1.435(3)

N1-C13 1.437(3)

C1-C2 1.524(3)

C1-C8 1.543(3)

C1-C9 1.549(3)

C2-C7 1.395(3)

C2-C3 1.400(3)

C3-C4 1.393(4)

C4-C5 1.378(4)

C5-C6 1.390(4)

C6-C7 1.390(4)

C6-C10 1.508(3)

C11-C12 1.521(3)

C11-C19 1.543(4)

C11-C18 1.556(4)

C12-C17 1.399(3)

C12-C13 1.402(3)

C13-C14 1.402(3)

C14-C15 1.371(3)

C15-C16 1.394(3)

C16-C17 1.383(3)

C16-C20 1.499(3)

C21-C22 1.523(4)

C22-C23 1.518(4)


Table A- 58. Bond angles [°] for 20. Bond Angle Bond Angle O3-W1-O2 97.06(8)

O3-W1-O1 95.23(8)

O2-W1-O1 165.07(8)

O3-W1-N1 129.69(9)

O2-W1-N1 83.37(8)

O1-W1-N1 82.27(8)

O3-W1-C21 108.82(10)

O2-W1-C21 92.15(9)

O1-W1-C21 91.87(9)

N1-W1-C21 121.46(9)

C1-O1-W1 142.07(16)

C11-O2-W1 142.37(16)

C3-N1-C13 113.55(19)

C3-N1-W1 124.01(15)

C13-N1-W1 122.11(15)

O1-C1-C2 110.6(2)

O1-C1-C8 108.0(2)

C2-C1-C8 111.1(2)

O1-C1-C9 103.1(2)

C2-C1-C9 112.8(2)

C8-C1-C9 110.9(2)

C7-C2-C3 119.8(2)

C7-C2-C1 120.1(2)

C3-C2-C1 120.2(2)

C4-C3-C2 118.0(2)

C4-C3-N1 119.5(2)

C2-C3-N1 122.5(2)

C5-C4-C3 121.3(2)

C4-C5-C6 121.3(2)

C7-C6-C5 117.5(2)

C7-C6-C10 120.0(2)

C5-C6-C10 122.5(2)

C6-C7-C2 121.9(2)

F2-C8-F1 107.5(2)

F2-C8-F3 107.9(2)

F1-C8-F3 107.0(2)

F2-C8-C1 111.9(2)

F1-C8-C1 110.5(2)

F3-C8-C1 111.7(2)

F4-C9-F6 108.4(2)

F4-C9-F5 107.2(2)

F6-C9-F5 106.6(2)

F4-C9-C1 110.8(2)

F6-C9-C1 113.1(2)

F5-C9-C1 110.5(2)

O2-C11-C12 111.7(2)

O2-C11-C19 106.7(2)

C12-C11-C19 110.9(2)

O2-C11-C18 104.4(2)

C12-C11-C18 112.6(2)

C19-C11-C18 110.2(2)

C17-C12-C13 119.4(2)

C17-C12-C11 119.8(2)

C13-C12-C11 120.8(2)

C14-C13-C12 117.5(2)

C14-C13-N1 118.8(2)

C12-C13-N1 123.7(2)

C15-C14-C13 121.9(2)

C14-C15-C16 121.1(2)

C17-C16-C15 117.4(2)

C17-C16-C20 121.1(2)

C15-C16-C20 121.4(2)

C16-C17-C12 122.5(2)

F7-C18-F9 107.5(2)

F7-C18-F8 108.1(2)

F9-C18-F8 107.0(2)

F7-C18-C11 110.7(2)

F9-C18-C11 111.1(2)

362

Table A- 61. Continued. Bond Angle Bond Angle F8-C18-C11 112.3(2)

F10-C19-F12 107.8(2)

F10-C19-F11 107.1(2)

F12-C19-F11 107.2(2)

F10-C19-C11 109.9(2)

F12-C19-C11 112.8(2)

F11-C19-C11 111.8(2)

C22-C21-W1 119.37(19)

C23-C22-C21 112.2(2)




U11 U22 U33 U23 U13 U12

W1 11(1) 13(1) 16(1) 3(1) 6(1) 2(1)

F1 20(1) 32(1) 16(1) 0(1) 2(1) 6(1)

F2 28(1) 45(1) 23(1) 3(1) 15(1) -5(1)

F3 42(1) 26(1) 22(1) -7(1) 10(1) 9(1)

F4 23(1) 26(1) 17(1) 1(1) 3(1) 7(1)

F5 18(1) 14(1) 29(1) 1(1) 9(1) 5(1)

F6 12(1) 25(1) 37(1) 4(1) 12(1) 2(1)

F7 30(1) 33(1) 22(1) -4(1) 7(1) -15(1)

F8 12(1) 30(1) 45(1) 17(1) 11(1) 4(1)

F9 18(1) 20(1) 38(1) 10(1) 13(1) -3(1)

F10 30(1) 44(1) 18(1) -8(1) 5(1) -2(1)

F11 48(1) 24(1) 29(1) 6(1) 24(1) 19(1)

F12 42(1) 33(1) 27(1) 12(1) 25(1) 9(1)

O1 12(1) 13(1) 24(1) -1(1) 9(1) 0(1)

O2 13(1) 12(1) 26(1) 4(1) 10(1) 4(1)

O3 20(1) 26(1) 20(1) 8(1) 11(1) 6(1)

N1 8(1) 14(1) 17(1) 1(1) 3(1) 2(1)

C1 10(1) 13(1) 16(1) 0(1) 6(1) 0(1)

C2 13(1) 14(1) 12(1) 2(1) 6(1) 2(1)

C3 14(1) 13(1) 12(1) 4(1) 4(1) 1(1)

C4 14(1) 18(2) 16(1) 0(1) 5(1) 6(1)

C5 23(1) 13(1) 15(1) -3(1) 6(1) 0(1)

C6 15(1) 17(2) 14(1) 2(1) 3(1) -1(1)

C7 12(1) 20(2) 17(1) 1(1) 5(1) 2(1)

C8 17(1) 22(2) 18(1) -1(1) 7(1) 2(1)

C9 14(1) 18(1) 22(1) -1(1) 8(1) 1(1)

C10 18(1) 18(2) 27(2) -1(1) 4(1) -2(1)

C11 10(1) 15(1) 15(1) 3(1) 5(1) 3(1)

C12 13(1) 12(1) 10(1) -1(1) 6(1) -1(1)

C13 14(1) 9(1) 12(1) -3(1) 4(1) 2(1)

C14 13(1) 16(1) 18(1) -3(1) 8(1) -2(1)

C15 18(1) 12(1) 14(1) -1(1) 6(1) -3(1)

C16 15(1) 11(1) 12(1) -2(1) 3(1) -1(1)

C17 11(1) 15(2) 13(1) -2(1) 4(1) -1(1)

C18 17(1) 19(2) 24(2) 9(1) 9(1) 1(1)

C19 24(2) 21(2) 20(2) 6(1) 12(1) 7(1)

C20 16(1) 18(2) 21(1) 7(1) 3(1) 0(1)

C21 17(1) 18(2) 21(1) 0(1) 6(1) 1(1)

C22 27(2) 27(2) 39(2) -12(2) 16(1) -6(1)

C23 27(2) 26(2) 35(2) -3(1) 3(1) -4(1)

363

A.8 DFT Calculations

Spin-restricted density functional theory calculations of complexes were

executed in the Gaussian 03 program suite. Calculations employed geometry

optimization and single point analysis using hybrid functional (the three-parameter

exchange functional of Becke (B3) and the correlation functional of Lee, Yang, and Parr

(LYP) (B3LYP). Full geometry optimization and single point analysis for the complexes

were performed using the LANL2DZ basis set. The atomic coordinates were generated

from Gabedit 2.3.0. Molecular orbital pictures were generated from Gabedit with

isovalues of 0.051687au.

Table A- 60. Atomic coordinates for the geometry optimized structure of 12. Atom x y z

W -0.12745 -1.08614 -0.29451

F 3.90526 -0.90583 0.469071

F 3.89004 -1.65156 -1.63545

F 5.011239 0.215578 -1.1324

F 3.003304 0.209846 -3.55598

F 3.574594 2.107173 -2.50412

F 1.414422 1.638585 -2.87029

F -4.09731 -0.59176 -2.27099

F -4.4724 -2.0963 -0.66299

F -5.57796 -0.15717 -0.63626

F -3.76437 -1.40866 1.939733

F -4.57599 0.677311 1.760095

F -2.40456 0.35175 2.209716

O 1.489991 -0.63172 -1.32539

O -2.08324 -1.02917 -0.32489

O -0.26758 -3.02829 -1.18753

N -0.27874 0.929631 -0.09915

C 2.505278 0.325479 -1.13454

C 2.202208 1.357805 -0.02189

C 0.870699 1.627367 0.409017

C 0.682353 2.610386 1.411257

C 1.752625 3.319335 1.959522

C 3.075933 3.07615 1.526012

C 3.270606 2.0968 0.538379

C 3.827622 -0.49244 -0.86357

C 2.638493 1.067798 -2.51625

C 4.246489 3.835739 2.120942

C -3.12363 -0.11955 -0.08009

C -2.74293 1.303936 -0.53261

C -1.3743 1.721334 -0.56289

C -1.11454 3.021981 -1.07857

364

Table A- 63. Continued. Atom x y z

C -2.13595 3.886204 -1.47445

C -3.49155 3.503415 -1.38033

C -3.76042 2.206795 -0.91517

C -4.32694 -0.72742 -0.89733

C -3.47545 -0.13136 1.453772

C -4.60795 4.447572 -1.78421

C 0.477852 -1.49288 1.320329

C 0.810842 -1.78321 2.758397

C 0.969409 -0.44128 3.531436

C 2.137885 -2.59177 2.850495

C -0.34777 -2.61029 3.391829

C 0.514105 -4.23663 -0.7693

C 1.657527 -4.51633 -1.74263

C -1.24338 -3.254 -2.31383

C -1.02881 -2.23553 -3.43098

H -0.33007 2.798816 1.7548

H 1.564255 4.061468 2.733014

H 4.28429 1.917495 0.195396

H 4.408044 3.558148 3.172053

H 4.073122 4.919538 2.094698

H 5.175428 3.631356 1.57737

H -0.08397 3.34462 -1.17103

H -1.87686 4.868363 -1.86581

H -4.79759 1.897084 -0.8491

H -4.63989 5.330939 -1.13117

H -5.5868 3.958459 -1.72818

H -4.47304 4.809397 -2.81252

H 1.191039 -0.64969 4.58748

H 0.048463 0.149618 3.479676

H 1.787505 0.158363 3.11689

H 2.382211 -2.78883 3.903643

H 2.967245 -2.04043 2.396648

H 2.049407 -3.56033 2.339518

Table A- 61. Atomic coordinates for the geometry optimized structure of 13. Atom x y z

W 0.081727 0.769395 0.07934

N -0.02057 -1.16183 -0.48527

C 2.751792 -1.57054 1.739777

F -3.97651 -1.00195 -2.95987

F -3.15943 1.05971 -3.29416

F -1.76755 -0.69728 -3.20096

F 3.131144 -0.73439 2.792038

C -1.24657 -1.865 -0.18993

F -3.91091 2.176779 -0.85321

C -3.57092 -3.41165 0.468937

F 3.562631 -2.70654 1.808228

C -1.14234 -3.14676 0.412189

F -3.91738 0.801235 0.907942

C -2.27017 -3.90349 0.728253

C -2.54961 -1.35104 -0.42981

F -5.20535 0.356503 -0.88322

C -2.72753 0.02727 -1.08443

365


F 1.448012 -1.99586 2.027041

C 0.652071 -2.79482 -2.19109

C -3.68037 -2.13633 -0.10499

C 3.325289 -2.66974 -1.42081

C 1.601736 -3.59412 -2.83142

C -2.91846 -0.14265 -2.63582

C 2.381576 -1.84629 -0.77015

C -3.94451 0.835991 -0.49476

C 1.010446 -1.91974 -1.13597

O -1.61688 0.876496 -0.91842

F 4.372839 0.222578 -1.19057

F 4.501695 0.802052 0.964387

O 1.980816 0.27248 0.347245

F 5.285809 -1.18447 0.308717

C 0.08731 2.769919 1.041259

C 0.173097 4.152301 1.664814

C -0.86703 1.404378 3.196218

C -1.38509 -0.05417 3.343128

C 1.119601 3.559784 -1.28426

C 0.506963 4.817254 -1.52482

C 1.051822 5.706276 -2.46566

C 2.8278 4.110827 -2.9522

C 2.282698 3.213804 -2.02042

C -0.39366 1.593961 1.766174

C 2.961803 -3.55386 -2.45065

C 0.558234 2.585918 -0.35977

C 2.800822 -0.86333 0.334078

C 4.24178 -0.26538 0.113867

C 3.997313 -4.41408 -3.14946

C -4.79981 -4.23206 0.810008

C 0.321257 1.603497 4.186459

C -2.03134 2.378606 3.54083

C 2.216348 5.360327 -3.17895

H -0.15264 -3.53419 0.627441

H -2.14384 -4.88248 1.186479

H -0.38635 -2.83394 -2.50157

H -4.67315 -1.75363 -0.31517

H 4.36685 -2.6324 -1.12137

H 1.286702 -4.25179 -3.63914

H -0.78793 4.669147 1.542443

H 0.945925 4.750263 1.175306

H 0.387247 4.088999 2.732777

H -0.59535 -0.77912 3.113435

H -2.23389 -0.24089 2.675342

H -1.71714 -0.22834 4.375005

H -0.41088 5.080287 -1.00553

H 0.565057 6.661093 -2.64886

366

Table A- 62. Atomic coordinates for the geometry optimized structure of [CF3-ONO]W≡N(OEt2).

Atom x y z

W -0.01166 -1.316234 -0.600527

F -3.913603 -1.229893 -1.515286

F -4.030253 -2.296927 0.443369

F -5.198502 -0.414432 0.140982

F -3.33012 -0.778441 2.697482

F -3.946094 1.246314 1.954514

F -1.785035 0.813864 2.364152

F 3.796878 -1.182565 1.617204

F 4.302323 -2.329171 -0.230359

F 5.366653 -0.413771 0.199896

F 3.891514 -1.030603 -2.662688

F 4.463343 1.025995 -1.968994

F 2.373435 0.622244 -2.679057

O -1.664664 -1.160067 0.450622

O 1.942803 -1.241175 -0.592126

O 0.186861 -3.391454 -0.17621

N 0.083467 0.667241 -0.393897

C -2.713813 -0.216503 0.368715

C -2.402922 1.011125 -0.527336

C -1.069872 1.404678 -0.840574

C -0.872706 2.542169 -1.655963

C -1.949557 3.293276 -2.132914

C -3.276638 2.933096 -1.809896

C -3.474692 1.797202 -1.00604

C -3.96657 -1.030831 -0.138139

C -2.959677 0.261459 1.845638

C -4.454314 3.724858 -2.34463

C 2.959918 -0.279118 -0.495816

C 2.50035 0.996421 0.242675

C 1.123777 1.379105 0.28121

C 0.790953 2.545441 1.020217

C 1.762716 3.328622 1.644984

C 3.130519 2.989386 1.565018

C 3.466005 1.820263 0.862885

C 4.116227 -1.037804 0.260229

C 3.431845 0.07891 -1.95439

C 4.19323 3.844268 2.228102

N -0.592797 -1.428933 -2.194471

C -0.43554 -4.474798 -1.021901

C -1.663433 -5.057921 -0.328612

C 1.093684 -3.8766 0.923597

C 0.858324 -3.074619 2.200824

H 0.145332 2.816337 -1.914712

H -1.762295 4.158219 -2.765696

H -4.494021 1.526383 -0.753022

H -4.668874 3.453191 -3.388017

H -4.254049 4.803205 -2.323259

H -5.363305 3.537462 -1.762241

H -0.252695 2.826533 1.101529

H 1.455409 4.210883 2.203073

H 4.514657 1.552057 0.797687

H 4.175274 4.87233 1.84169

367


H 5.197335 3.441329 2.056621

H 4.037471 3.902994 3.314008

H 0.351234 -5.216807 -1.202695

H -0.688029 -3.971781 -1.956629

H -2.125404 -5.802596 -0.990257

H -2.399306 -4.274613 -0.123699

H -1.408341 -5.558547 0.613281

H 0.857782 -4.934655 1.069911

H 2.112562 -3.764881 0.540445

H 1.481769 -3.494621 3.000402

H -0.190227 -3.120197 2.512224

H 1.155383 -2.026312 2.086853

368

Figure A- 176. Truncated molecular orbital diagram of [CF3-ONO]W≡N(OEt2).

369

Figure A- 177. Labeling Scheme of the geometry optimization structure for 16’.

Figure A- 178. Guassian optimized IR spectrum for 16’.

Table A- 63. Atomic coordinates of the geometry optimization calculation for 16’. Atom x y z

W1 -0.0409 -1.0611 0.2816

O3 -0.0307 -2.8045 -0.2955

O2 -1.9879 -0.9337 0.1985

O1 1.6624 -0.7544 -0.6847

N1 -0.2099 0.9342 0.0761

F9 -4.118 -0.8952 -1.6468

F8 -4.4186 -2.0004 0.2741

F7 -5.4852 -0.067 -0.0667

F6 3.7799 -0.7689 1.3622

F5 5.1488 0.1355 -0.1766

F4 4.0975 -1.7899 -0.6015

370


F3 3.9524 1.6741 -2.1331

F2 3.3662 -0.3547 -2.8888

F12 -2.1509 0.9511 2.4232

F11 -3.5306 -0.8041 2.6137

F10 -4.3423 1.2102 2.0389

F1 1.807 1.2346 -2.6162

C9 3.9294 -0.5425 -0.0107

C8 2.9638 0.686 -2.0551

C7 3.2803 2.2873 0.7953

C6 2.9816 3.4071 1.5874

C5 1.6209 3.6704 1.8642

C4 0.6155 2.8509 1.3477

C3 0.9137 1.7334 0.5274

C27 1.2944 -4.5194 -1.369

C26 -1.1393 -4.9189 -0.6738

C25 -0.6006 -3.3298 -2.5999

C24 -0.1215 -3.9238 -1.2593

C23 1.3996 -3.5024 2.5443

C22 1.0725 -2.0968 3.0829

C21 0.4793 -1.095 2.1067

C20 -4.423 4.1175 -2.3745

C2 2.2782 1.4362 0.2743

C19 -3.2703 0.3318 1.8515

C18 -4.2645 -0.729 -0.2681

C17 -3.6455 2.1055 -1.0224

C16 -3.3323 3.2537 -1.7715

C15 -1.9676 3.5711 -1.9395

C14 -0.9691 2.7954 -1.3435

C13 -1.2804 1.6628 -0.5517

C12 -2.6516 1.3015 -0.4287

C11 -3.0139 0.0162 0.3299

C10 4.0785 4.2936 2.1447

C1 2.6736 0.2206 -0.5831

Figure A- 179. Labelling Scheme of the geometry optimization calculation for 16-Me’.

371

Figure A- 180. Guassian optimizated IR spectrum calculation for 16-Me’.

Table A- 64. Atomic coordinates of the geometry optimization calculation for 16-Me’. Atom x y z

W1 0.2132 0.94 0.191

O3 0.4645 2.8454 -0.7416

O2 2.0871 0.812 0.2758

O1 -1.4882 0.8203 -0.6099

N1 0.2258 -1.0408 0.1267

F9 5.5042 -0.0203 -0.5445

F8 4.4196 1.9084 -0.1519

F7 3.905 0.6952 -1.9653

F6 -4.8618 -0.1926 -1.3608

F5 -3.7903 1.7678 -1.313

F4 -4.1503 0.678 0.5982

F3 -2.9253 -1.7887 -2.7146

F2 -2.6108 0.3708 -3.2767

F12 4.601 -1.4049 1.6655

F11 4.0614 0.6939 2.2912

F10 2.5127 -0.9253 2.3824

F1 -0.8665 -0.8725 -2.6328

C9 -3.8191 0.5045 -0.7501

C8 -2.2244 -0.6304 -2.3968

C7 -3.3538 -2.2314 0.4212

C6 -3.2279 -3.3229 1.2963

C5 -1.9511 -3.604 1.8196

C4 -0.8344 -2.84 1.4423

C3 -0.957 -1.7622 0.5441

C28 1.2399 2.7338 -2.018

C27 1.1663 5.2423 -0.5001

C26 -1.1318 4.6159 -1.4807

C25 -0.6346 4.3089 0.9755

C24 -0.0559 4.3212 -0.4351

C23 -1.866 0.3669 3.7238

C22 -1.6371 1.4238 2.6793

C21 -0.3095 1.2522 1.9865

C20 4.3248 -4.4022 -2.3371

C2 -2.2495 -1.4299 0.0508

372


C19 3.6034 -0.4451 1.638

C18 4.263 0.605 -0.6183

C17 3.6208 -2.2774 -1.0806

C16 3.2808 -3.4847 -1.7271

C15 1.918 -3.8103 -1.7951

C14 0.9403 -2.9953 -1.2056

C13 1.2721 -1.8001 -0.5248

C12 2.6516 -1.4303 -0.5025

C11 3.1352 -0.1461 0.1743

C10 -4.4356 -4.1715 1.6573

C1 -2.4314 -0.222 -0.8944

Figure A- 181. Labeling Scheme of the geometry optimization calculation for 17’.

Figure A- 182. Guassian optimizated IR spectrum calculation for 17’.

373


W1 0.0531 1.1305 -0.2795

O3 0.0821 2.8351 -1.1551

O2 2.0414 1.0396 -0.2245

O1 -1.6124 0.5411 -1.2181

N1 0.2997 -0.9962 -0.2244

F9 4.3016 0.8284 -1.9721

F8 4.4452 2.1516 -0.1783

F7 5.5682 0.2261 -0.219

F6 -3.7794 0.7943 0.8809

F5 -5.0841 -0.3389 -0.552

F4 -4.069 1.5388 -1.2041

F3 -3.8482 -2.1839 -2.1446

F2 -3.4055 -0.286 -3.2481

F12 2.1401 -0.5929 2.1972

F11 3.5559 1.1408 2.2412

F10 4.3281 -0.9362 1.8895

F1 -1.7545 -1.7344 -2.7938

C9 -3.869 0.3845 -0.4527

C8 -2.9031 -1.1462 -2.2657

C7 -3.1266 -2.2282 0.8159

C6 -2.8042 -3.2469 1.7236

C5 -1.432 -3.5103 1.9461

C4 -0.4477 -2.781 1.2809

C3 -0.7605 -1.7432 0.3548

C27 0.5838 4.8224 0.1644

C26 0.2116 4.9109 -2.3521

C25 -1.7423 4.406 -0.7982

C24 -0.2222 4.2559 -1.0245

C23 -1.8541 2.6531 3.1181

C22 -0.8456 1.5094 2.8312

C21 -0.4785 1.3619 1.3917

C20 4.7628 -4.1589 -2.2048

C2 -2.1442 -1.4713 0.1335

C19 3.2684 -0.059 1.5782

C18 4.3349 0.8219 -0.5761

C17 3.8213 -2.0655 -1.0953

C16 3.6079 -3.3198 -1.6871

C15 2.2693 -3.7604 -1.8038

C14 1.2136 -2.983 -1.3309

C13 1.4144 -1.7159 -0.7017

C12 2.7674 -1.2547 -0.6165

C11 3.0538 0.1171 0.0219

C10 -3.883 -4.0309 2.45

C1 -2.5811 -0.4177 -0.9053

374

Figure A- 183. Labeling Scheme of the geometry optimization calculation for 21’.

Figure A- 184. Guassian optimizated IR spectrum calculation for 21’.

375


W1 0.0187 0.1921 -0.431

O3 0.0207 -1.778 -0.2805

O2 1.9643 0.1041 0.1867

O1 -1.9629 0.0791 -0.0219

N1 -0.0383 2.1264 0.3166

F9 3.027 1.7553 -1.9033

F8 5.0498 0.8345 -1.7163

F7 3.3159 -0.4184 -2.3746

F6 -3.5951 1.2859 1.9272

F5 -3.2951 2.5854 0.1201

F4 -5.2639 1.5845 0.4668

F3 -3.0533 1.3346 -2.3643

F2 -3.3314 -0.8829 -2.4415

F12 5.2641 1.5091 0.9152

F11 3.5861 0.9737 2.2984

F10 3.3011 2.5656 0.7473

F1 -5.0688 0.4508 -1.9887

C9 -3.8658 1.3957 0.5684

C8 -3.6917 0.2647 -1.7345

C7 -5.4171 -1.3535 0.3341

C6 -5.9739 -2.5109 0.9077

C5 -5.1478 -3.4623 1.5354

C4 -3.7573 -3.2497 1.58

C36 0.2408 1.2472 2.6152

C35 -0.0184 1.3171 3.994

C34 -0.7361 2.3966 4.5405

C33 -1.1948 3.4097 3.6726

C32 -0.95 3.3417 2.294

C31 -0.2278 2.2542 1.7285

C30 -0.6608 3.5718 -1.6094

C3 -3.1946 -2.0963 1.0044

C29 -0.5173 4.7649 -2.3391

C28 0.3587 5.7776 -1.9013

C27 1.089 5.5737 -0.7127

C26 0.9484 4.3829 0.0177

C25 0.0754 3.3533 -0.4212

C24 0.1252 -4.1812 -0.1095

C23 1.3466 -2.9726 -1.9837

C22 -1.1728 -3.083 -1.9895

C21 0.0827 -2.9911 -1.0949

C20 0.23 0.7625 -3.6213

C2 -4.0219 -1.142 0.3818

C19 0.1333 0.5225 -2.1569

C18 3.8667 1.315 0.9743

C17 3.673 0.5987 -1.4852

C16 5.4364 -1.3509 0.2117

C15 6.0226 -2.5565 0.6382

C14 5.2385 -3.5526 1.2501

C13 3.8588 -3.337 1.4238

C12 3.2669 -2.1371 0.9909

C11 4.0515 -1.1372 0.3856

C10 3.3331 0.1896 -0.0018

C1 -3.329 0.1241 -0.2037

376

Figure A- 185. Molecular Orbital Diagram of 16-Me’ containing LUMO – HOMO(-5).

(Isovalue = 0.051687) .

377

Figure A- 186. Molecular Orbital Diagram of 17’ containing LUMO – HOMO(-5).

(Isovalue = 0.051687) .

378

Figure A- 187. Molecular Orbital Diagram of 21’ containing LUMO – HOMO(-5).

(Isovalue = 0.051687) .

379

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BIOGRAPHICAL SKETCH

Matthew Elijah O’Reilly was born in Peekskill, NY to his father and mother, Kevin

and Ann O’Reilly. His family moved to Greenville, NY. There, he attended Hosanna

Christian Academy untll 8th grade, homeschooled in 9th grade, and then finally attended

Greenville Central High School. Upon graduating from high school, he received the

August C. Stiefel science award. For his university studies, he attended SUNY Albany

for a year before transferring to Lee University in Cleveland, TN. As an adolescent,

Matthew had an affinity for science and cooking, thus he pursued chemistry as his

major. He participated in two Research for Undergraduates Experiences at North

Carolina State University and Université Louis Pasteur during his undergraduate

studies. Upon graduting from Lee, Matthew received the Lee University Chemistry

Department Award. Thereafter he attended the University of Florida for his graduate

studies. During that time, he received the Eastman Chemical Fellowship and was a

selected participant to the 2013 Lindau Meeting. He received his Ph.D. from the

University of Florida in August 2013.