ELECTRONIC-STRUCTURES OF THE ICOSAHEDRAL C60H60 AND C60F60 MOLECULES

Electronic structures of the icosahedral C60H60 hydrocarbon and its perfluoro analog, C60F60, are examined at the HF/4-31G and HF/6-31G** levels. The calculated C-C bond lengths are as large as 1.57 angstrom in C60H60 and 1.63 angstrom in C60F60. The bond lengthening is attributed to the H-H and F-F steric interactions rather than to rehybridization effects. Topological analysis of the electron densities reveals the presence of curved C-C bond paths. In addition, F-F bond paths are found in C60F60 indicating strong non-bonded interaction between the fluorine atoms. The same conclusion is reached from the calculated energy of the isodesmic transfluorination reaction involving the C2H6, C2F6, C60H60. and C60F60 molecules.