View
220
Download
3
Tags:
Embed Size (px)
Citation preview
1
Abstract:
• Cycloaddition of bromomalonates to Y3N@C80 unexpectedly gave rise to fulleroid derivatives with unusually high stability. Complete characterization of these derivatives is described including X-ray crystallography, 1H NMR, 13C NMR, HMQC, UV-visible, HPLC, MALDI-MS, and electrochemistry. Density functional theory calculations are also presented, which provide a rationale for the formation of the fulleroid and reveal the underlying thermodynamic basis for their stability.
2
“Open Rather than Closed” Malonate Methano-Fullerene Derivatives.
The Formation of Methanofulleroid Adducts of Y3N@C80
Olena Lukoyanova, Claudia M. Cardona, Jose´ Rivera, Leyda Z. Lugo-Morales,Christopher J. Chancellor, Marilyn M. Olmstead, Antonio Rodrı´guez-Fortea,
Josep M. Poblet*, Alan L. Balch, and Luis Echegoyen*
J. Am. Chem. Soc. 2007, 129, 10423-10430
演講者:莊雲婷
3
Properties of C60
• Six-membered ring : 20• Five-membered ring : 12• [5,6] bonds : 60
(bond length : 1.45Å)• [6,6] bonds : 30
(bond length : 1.38Å)• Averge diameter : 7.1 Å
http://nano.nchc.org.tw/dictionary/c60.html
4
Electrochemical Detection of C606-
Echegoyen. L. et. al. J. Am. Chem. Soc. 1992, 114, 3978-3980.
5
13C NMR Spectrum of C60 in C6D6
Jingcheng H ,et al ; J. Phys. Chem. B 2006, 110, 68-74
6
Mass Spectrum of C60
Mehlig.K ,at al ; J. Chem. Phys., 2003,119,5591-5600
7
Properties of C80
• Six-membered ring : 30• Five-membered ring : 12• [5,6] bonds : 60• [6,6] bonds :60• Averge diameter : 8.2 Å
http://www.fullereneinternational.com/fic/fullerenes.html
8
Endohedral Metallofullerene ( EMF )
Stevenson, S.; et al. Nature 1999, 401, 55-57
Sc3N@C80
Shinohara, H.; et al. Bioconjugate Chem. 2001, 12, 510-514
9
Synthesis of Y3N@(N-ethylpyrrolidino-C80)
Echegoyen, L.et.al; J. Am. Chem. Soc. 2005, 127, 10448-10453
[5.6]&[6,6]
Y3NDiels-Alder cycloadduct
10
[5,6] and [6,6] Junction for Cycloaddition
Echegoyen, L.; et al. Angew. Chem., Int. Ed. 2006, 45, 8176-8180
[5,6]
[6,6][5,6]
[6,6]
11
Interconversion of [6,6] to [5,6]
Y3N@pyrrolidino-C80
Echegoyen, L.; et al. Angew. Chem., Int. Ed. 2006, 45, 8176-8180
[6,6] [5,6]
13
Retro-Cyclopropanation Reaction
Echegoyen, L,et al ; Eur. J. Org. Chem. 2004,2299-2316.
14
Synthesis Bingel-Hirsch Adducts
1, Y3N@C80-C(CO2Et)2. Yield 85%
2, Y3N@C80-C(CO2CH2Ph)2. Yield 76%
N
N
1,8-diazabicyclo[5.4.0]-undec-7-ene (DBU)
Cl
Cl
o-dichlorobenzene
( ODCB )
15
Cyclic Voltammetry of Compound 1
16
MALDI-MS Spectrum of Comound 1
• 1, Y3N@C80-C(CO2Et)2, after chemical reduction with sodium metal in THF.
• Matrix-Assisted Laser Desorption Ionization .
17
Y3N@C80-C(CO2CH2Ph)2
Sc3N@C80 C1-C9 1.421 Å.
C1-C9 : 2.30 Å
open
18
Orientations of Fullerene Cage in 2
five-membered ring containing C1 on the left side
six-membered ring containing C9 on the right side.
six-membered ring containing C1 on the left side
five-membered ring containing C9 on the right side.
C1 C9
19
Three Orientations of the Y3N Units in 2
0.7 occupancy 0.21 occupancy 0.09 occupancy
90 K
20
1H NMR Spectra of 2
dd
d
H H
22
13C NMR Spectrum
downfield
23
HMQC
• Heteronuclear Multiple Quantum Coherence (HMQC) is selective for direct C-H coupling .
http://www.chemistry.msu.edu/facilities/nmr/HMQC.html
13C NMR
1H NMR
24
HMQC Spectrum
13C NMR
1H NMR
25
UV-Visible Spectra
26
Relative Position of the Y3N Unit in Y3N@C80-C(CO2CH3)2
isomer [5,6] [6,6]
I1 -73.0 (4.8) -77.7 (0.0)
I2 -60.4 (17.4) -51.6 (26.2)
I3 -74.4 (3.4) -77.3 (0.5)
I4 -73.8 (3.9) -75.6 (2.2)
I5 -45.7 (32.1) -46.3 (31.5)
I6 -57.0 (20.7) -52.3 (25.4)
I7 -48.5 (29.3) -50.4 (27.3)
I8 -49.5 (28.2) -49.1 (28.6)
a BE =E[Y3N@C80-C(CO2CH3)2] - E[Y3N@C80] -E[C(COOCH3)2].b The calculations were using DFT with B3PW91 / 6-311G(2d,p)
Bond Energiesaab (in kcal mol-1)
I1 I3 I4
28
Distances of the [6,6]-Methano Derivative of Y3N@C80
Distances(Å) X-ray DFTa
Y1-N 2.066 2.081
Y2-N/Y3-N 2.070 2.072
C1···C9 2.29 2.277
C1-C81/C9-C81 1.533 1.503
Y1-C1/Y1-C9 2.528 2.549
a B3PW91 / 6-311G(2d,p)
29
Representations of Functionalized La2@C80
Y3N@C80 La2@C80
Distances(Å) I1 I5 M1 M2
C81-C1a 1.503 1.505 1.500 1.490
C1···C9a 2.277 1.657 2.206 2.192
Charge transfer b 2.91 2.78 2.70 2.89
DFT Calaulation
a B3PW91 / 6-311G(2d,p)b multipole derived charge method(MDC-q)
30
Representations of Functionalized Sc2@C80
La2@C80 Sc2@C80
Distances(Å)
C80 M1 M2 M3 M4
C81-C1a 1.514 1.500 1.490 1.490 1.512
C1···C9a 1.625 2.206 2.192 2.184 1.646
Charge transfer b 2.70 2.89 1.02 0.53
DFT Calaulation
a B3PW91 / 6-311G(2d,p)b multipole derived charge method(MDC-q)
31
Rearrangement To Form the 2 Fulleroid
Bingel-Hirsch Cycloaddition [6,6]
[5,6]
Norcaradiene Rearrangement
OPEN
32
Conclusions
• It is also apparent that the endohedral cluster plays a major role in directing the addition sites to EMFs.
• A possible thermally induced Norcaradiene rearrangement might occur instead subsequent to the [6,6]-addition to result in cleavage of the cyclopropane ring and formation of an opening in the fullerene cage.
• After a thorough experimental and theoretical characterization and analysis of the malonate monoadducts of Y3N@C80, we conclude that their stability must be attributed to the cage-open fulleroid structure.