Thermodynamically and kinetically stable isomers of the C 88 and C 90 fullerenes

Abstract

Isolable or extractable fullerene isomers must be not only thermodynamically but also kinetically stable. Heats of atomization and anion localization energies (anion LEs) for all isolated-pentagon isomers of the C 88 and C 90 fullerenes were calculated using the PM3 method. The heat of atomization is a direct index of thermodynamic stability, whereas the minimum anion LE (min anion LE) in a molecule serves as a measure of kinetic stability for electron-deficient fullerenes. On this theoretical basis, we successfully predicted the fullerene isomers that might appear in experimental samples of C 88 and C 90. For the fullerene isomers studied, HOMO–LUMO energy separation is not highly correlative with min anion LE. It seems likely that, with a notable exception of C 72, the C 6 n fullerenes are generated more abundantly than their neighboring members.