Thermodynamically and kinetically stable isomers of the C88 and C90 fullerenes

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 C88 and C90 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 C88 and C90. 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 C72, the C6n fullerenes are generated more abundantly than their neighboring members.