Kinetic stability of fullerenes with four-membered rings

The bond resonance energy (BRE, E(br)) represents the contribution of a given pi bond in a molecule to the topological resonance energy (TRE, E(tr)). It is useful for seeking the reactive sites in a cyclic pi-electron system. Calculated E(br)s support the view that some fullerenes with two four-membered and four fewer five-membered rings might be more stable than the normal fullerene isomers. Some such fullerenes have no highly reactive pi bonds, presumably being capable of formation and survival during synthetic processes.