Kinetic Stability of C_(78) Fullerene Isomers as Revealed by the Bond Resonance Energy Method

摘要

Relative yields of C_(78) fullerene isomers are very sensitive to He pressure in the graphite vaporization chamber. This phenomenon can be explained in terms of the bond resonance energy (BRE), a measure of kinetic stability proposed by us. It was found that the thermodynamically most stable isomer of C_(78) is not kinetically very stable. Consequently, when He pressure is low, Kinetically more stable isomers, rather than the lowest-energy isomer, have a larger chance of survival. At higher He pressure, the lowest-energy isomer is generated preferentially and so will earn a large chance of isolation. Thus, kinetic stability has a crucial influence on the yield of the various isomers in the product. A small HOMO-LUMO gap is closely related to the existence of highly reactive substructures in the molecule.