The Experts below are selected from a list of 3621 Experts worldwide ranked by ideXlab platform
Gustavo E. Scuseria - One of the best experts on this subject based on the ideXlab platform.
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a theoretical study of Buckminsterfullerene reaction products c60 c60
Chemical Physics Letters, 1993Co-Authors: Douglas L. Strout, Robert L. Murry, W. C. Eckhoff, Gregory K. Odom, Gustavo E. ScuseriaAbstract:Abstract Several possible structures for reaction products of two Buckminsterfullerene (C60) molecules are presented and discussed. Geometries are optimized with the MNDO and tight-binding methods, followed by single-point energy calculations using the Hartree—Fock self-consistent field procedure and a recently proposed hybrid of Hartree—Fock and density functional theory. Our results are discussed in the context of recent experimental evidence of the solid-state polymerization of C60 and the coalescence of Buckminsterfullerene by laser desorption of a film. The theoretical predictions are consistent with a polymerization process that proceeds through 2 + 2 cycloaddition of fullerene double bonds.
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A theoretical study of Buckminsterfullerene reaction products: C60+C60
Chemical Physics Letters, 1993Co-Authors: Douglas L. Strout, Robert L. Murry, W. C. Eckhoff, Gregory K. Odom, Gustavo E. ScuseriaAbstract:Abstract Several possible structures for reaction products of two Buckminsterfullerene (C60) molecules are presented and discussed. Geometries are optimized with the MNDO and tight-binding methods, followed by single-point energy calculations using the Hartree—Fock self-consistent field procedure and a recently proposed hybrid of Hartree—Fock and density functional theory. Our results are discussed in the context of recent experimental evidence of the solid-state polymerization of C60 and the coalescence of Buckminsterfullerene by laser desorption of a film. The theoretical predictions are consistent with a polymerization process that proceeds through 2 + 2 cycloaddition of fullerene double bonds.
Douglas L. Strout - One of the best experts on this subject based on the ideXlab platform.
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a theoretical study of Buckminsterfullerene reaction products c60 c60
Chemical Physics Letters, 1993Co-Authors: Douglas L. Strout, Robert L. Murry, W. C. Eckhoff, Gregory K. Odom, Gustavo E. ScuseriaAbstract:Abstract Several possible structures for reaction products of two Buckminsterfullerene (C60) molecules are presented and discussed. Geometries are optimized with the MNDO and tight-binding methods, followed by single-point energy calculations using the Hartree—Fock self-consistent field procedure and a recently proposed hybrid of Hartree—Fock and density functional theory. Our results are discussed in the context of recent experimental evidence of the solid-state polymerization of C60 and the coalescence of Buckminsterfullerene by laser desorption of a film. The theoretical predictions are consistent with a polymerization process that proceeds through 2 + 2 cycloaddition of fullerene double bonds.
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A theoretical study of Buckminsterfullerene reaction products: C60+C60
Chemical Physics Letters, 1993Co-Authors: Douglas L. Strout, Robert L. Murry, W. C. Eckhoff, Gregory K. Odom, Gustavo E. ScuseriaAbstract:Abstract Several possible structures for reaction products of two Buckminsterfullerene (C60) molecules are presented and discussed. Geometries are optimized with the MNDO and tight-binding methods, followed by single-point energy calculations using the Hartree—Fock self-consistent field procedure and a recently proposed hybrid of Hartree—Fock and density functional theory. Our results are discussed in the context of recent experimental evidence of the solid-state polymerization of C60 and the coalescence of Buckminsterfullerene by laser desorption of a film. The theoretical predictions are consistent with a polymerization process that proceeds through 2 + 2 cycloaddition of fullerene double bonds.
Fred Wudl - One of the best experts on this subject based on the ideXlab platform.
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Semiconducting polymers (as donors) and Buckminsterfullerene (as acceptor): photoinduced electron transfer and heterojunction devices
Synthetic Metals, 1993Co-Authors: N. Serdar Sariciftci, Alan J. Heeger, L. Smilowitz, Fred WudlAbstract:Abstract Experimental results on the metastable, reversible, photoinduced electron transfer between semiconducting polymers and Buckminsterfullerene are reviewed. Photoinduced absorption (photoexcitation spectroscopy), steady state and picosecond time-resolved photoluminescence and light-induced electron spin resonance measurements are summarized as experimental evidence for photoinduced electron transfer. Comparative studies with different semiconducting polymers as donors demonstrate that in the degenerate ground state the polymer's soliton excitations form before the electron transfer can occur, thereby inhibiting charge separation. In non-degenerate ground state systems, photoinduced electron transfer occurs in less than 10 −12 s, quenching the photoluminescence as well as the intersystem crossing. The importance of electron-phonon coupling in these low-dimensional semiconductor polymers, resulting in structural relaxation upon photoexcitation, is proposed to contribute to the stabilization of the charge-separated state. Utilizing thin films of the semiconducting polymer (donor) and Buckminsterfullerene (acceptor) to form a heterojunction interface, we fabricated diode bilayers which functioned as photodiodes and as photovoltaic cells. The results are discussed in terms of opportunities for solar energy conversion, for photodiode detector devices and for a variety of other applications which use photoinduced intermolecular charge separation.
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a polyester and polyurethane of diphenyl c61 retention of fulleroid properties in a polymer
Journal of the American Chemical Society, 1992Co-Authors: K C Khemani, Q Li, Fred WudlAbstract:A polyester and a polyurethane containing Buckminsterfullerene C 60 as pendant group (charm bracelet) were prepared. While the poyurethane is insoluble, the polyester is much more tractable. The remarkable retention of the electronic structure of the C 60 moieties as witnessed by UV-vis spectroscopy and cyclic voltammetry augurs well for observation of unusual fullerene-type properties of products fabricated from these polymers
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Buckminsterfullerene c60 and organic ferromagnetism
Journal of Physics and Chemistry of Solids, 1992Co-Authors: Fred Wudl, Joe D ThompsonAbstract:Abstract Interest in the electronic properties of C60 led to the discovery of metals, superconductors and a solid with a transition to a magnetic state. The approaches to organic ferromagnets are reviewed briefly, with emphasis on the McConnell model. The review is followed by the description of the magnetic properties of C60 TDAE at ambient pressure and under hydrostatic pressure, showing that the 16 K transition is extremely pressure sensitive and that the effect of pressure is reversible. An explanation of the properties of C60 TDAE in terms of a modification of the McConnell model is described for the first time.
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The chemical properties of Buckminsterfullerene (C60) and the birth and infancy of fulleroids
Accounts of Chemical Research, 1992Co-Authors: Fred WudlAbstract:In this account, the emphasis is on the high electron affinity of Buckminsterfullerene, where reductions, nucleophilic additions, and oxidative additions of low-valent transition metals are considered as the sole avenues to fullerene C[sub 60] functionalization and modification. However, it should be mentioned that electrophilic additions have also been reported.
Sergey I. Troyanov - One of the best experts on this subject based on the ideXlab platform.
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Rebuilding C60: Chlorination-Promoted Transformations of the Buckminsterfullerene into Pentagon-Fused C60 Derivatives.
Inorganic chemistry, 2018Co-Authors: Victor A. Brotsman, Ilya N. Ioffe, Erhard Kemnitz, Nadezhda B. Tamm, Vitaliy Yu. Markov, Alexey A. Goryunkov, Sergey I. TroyanovAbstract:In recent years, many higher fullerenes that obey the isolated pentagon rule (IPR) were found capable of rearranging into molecules with adjacent pentagons and even with heptagons via chlorination-promoted skeletal transformations. However, the key fullerene, Buckminsterfullerene Ih-C60, long seemed insusceptible to such rearrangements. Now we demonstrate that Buckminsterfullerene yet can be transformed by chlorination with SbCl5 at 420–440 °C and report X-ray structures for the thus-obtained library of non-IPR derivatives. The most remarkable of them are non-IPR C60Cl24 and C60Cl20 with fundamentally rearranged carbon skeletons featuring, respectively, four and five fused pentagon pairs (FPPs). Further high-temperature trifluoromethylation of the chlorinated mixture afforded additional non-IPR derivatives C60(CF3)10 and C60(CF3)14, both with two FPPs, and a nonclassical C60(CF3)15F with a heptagon, two FPPs, and a fully fused pentagon triple. We discuss the general features of the addition patterns in th...
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Rebuilding C60: Chlorination-Promoted Transformations of the Buckminsterfullerene into Pentagon-Fused C60 Derivatives
2018Co-Authors: Victor A. Brotsman, Ilya N. Ioffe, Erhard Kemnitz, Nadezhda B. Tamm, Vitaliy Yu. Markov, Alexey A. Goryunkov, Sergey I. TroyanovAbstract:In recent years, many higher fullerenes that obey the isolated pentagon rule (IPR) were found capable of rearranging into molecules with adjacent pentagons and even with heptagons via chlorination-promoted skeletal transformations. However, the key fullerene, Buckminsterfullerene Ih-C60, long seemed insusceptible to such rearrangements. Now we demonstrate that Buckminsterfullerene yet can be transformed by chlorination with SbCl5 at 420–440 °C and report X-ray structures for the thus-obtained library of non-IPR derivatives. The most remarkable of them are non-IPR C60Cl24 and C60Cl20 with fundamentally rearranged carbon skeletons featuring, respectively, four and five fused pentagon pairs (FPPs). Further high-temperature trifluoromethylation of the chlorinated mixture afforded additional non-IPR derivatives C60(CF3)10 and C60(CF3)14, both with two FPPs, and a nonclassical C60(CF3)15F with a heptagon, two FPPs, and a fully fused pentagon triple. We discuss the general features of the addition patterns in the new non-IPR compounds and probable pathways of their formation via successive Stone–Wales rearrangements
Sven J. Cyvin - One of the best experts on this subject based on the ideXlab platform.
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Vibrational redundant coordinates of Buckminsterfullerene
Chemical Physics Letters, 1996Co-Authors: E. Martínez-torres, E. Brendsdal, Juan Jesús López-gonzález, Manuel Fernández-gómez, Sven J. CyvinAbstract:From symmetry and geometry arguments, the symmetry adapted vibrational redundant coordinates for the molecule of Buckminsterfullerene have been obtained as linear combinations of simple internal valence coordinates.
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Mean Amplitudes of Vibration and Related Quantities for Buckminsterfullerene
Spectroscopy Letters, 1992Co-Authors: E. Brendsdal, J. Brunvoll, Bjørg N. Cyvin, Sven J. CyvinAbstract:Abstract Previous works on the molecular vibrations of C60 Buckminsterfullerene are reviewed briefly. Here both the theoretical and experimental works are taken into account. New calculations of mean amplitudes of vibration and related quantities for 12C60 are reported. These results are of great interest in the gas electron diffraction investigation of this molecule. The corresponding data are also given for 13C60 isotopic Buckminsterfullerene.
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Condensed aromatics—XXVI. Vibrational frequencies of 13C60 isotopic Buckminsterfullerene
Spectrochimica Acta Part A: Molecular Spectroscopy, 1992Co-Authors: Bjørg N. Cyvin, E. Brendsdal, J. Brunvoll, Sven J. CyvinAbstract:Abstract The force-field of molecular vibrations of C 60 Buckminsterfullerene is refined and used to calculate the frequencies of 13 C 60 isotopic Buckminsterfullerene. The resulting IR-active frequencies show very good agreement with experimental data from literature. It is suggested that the predicted Raman-active frequencies for 13 C 60 are reliable. Calculated Coriolis coupling constants for the IR-active frequencies are given.
