1

Abstract: • Cycloaddition of bromomalonates to Y3N@C80 u

nexpectedly 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

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Mass Spectrum of C60

Mehlig.K ,at al ; J. Chem. Phys., 2003,119,5591-5600

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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

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Endohedral Metallofullerene ( EMF )

Stevenson, S.; et al. Nature 1999, 401, 55-57

Sc3N@C80

Shinohara, H.; et al. Bioconjugate Chem. 2001, 12, 510-514

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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

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[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]

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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]

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Retro-Cyclopropanation Reaction

Echegoyen, L,et al ; Eur. J. Org. Chem. 2004,2299-2316.

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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 )

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Cyclic Voltammetry of Compound 1

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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 .

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Y3N@C80-C(CO2CH2Ph)2

Sc3N@C80 C1-C9 1.421 Å.

C1-C9 : 2.30 Åopen

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Orientations of Fullerene Cage in 2five-membered ring containing

C1 on the left sidesix-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

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Three Orientations of the Y3N Units in 2

0.7 occupancy 0.21 occupancy 0.09 occupancy

90 K

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1H NMR Spectra of 2

dd

d

H H

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13C NMR Spectrum

downfield

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HMQC• Heteronuclear Multiple Quantum Coherence (HMQC) is s

elective for direct C-H coupling .

http://www.chemistry.msu.edu/facilities/nmr/HMQC.html

13C NMR

1H NMR

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HMQC Spectrum

13C NMR

1H NMR

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UV-Visible Spectra

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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

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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)

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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)

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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)

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Rearrangement To Form the 2 Fulleroid

Bingel-Hirsch Cycloaddition [6,6]

[5,6]

Norcaradiene Rearrangement

OPEN

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Conclusions• It is also apparent that the endohedral cluster plays a ma

jor 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.