FULLERENE ISOMERS OF C-60 - KEKULE COUNTS VERSUS STABILITY

A count of Kekule structures for all 1812 distinct fullerene isomers o f C-60 shows that 20 isomers surpass the count of 12500 for icosahedra l C-60, and demonstrates the lack of correlation between molecular-orb ital indices of stability and raw Kekule counts for fullerenes. Analys is of Kekule structures in terms of benzenoid, cyclopentenoid and cycl opentadienoid rings reveals the source of the stability of icosahedral C-60 in a localised model to be the fact that uniquely amongst the 18 12 structural isomers it has a Fries Kekule structure where all hexago ns contain three double bonds and all pentagons none.