Isolated pentagon rule violating endohedral metallofullerenes explained using the Hückel rule: A statistical mechanical study of the C^sub 84^ Isomeric Set

Fullerenes and their structure and stability have been a major topic of discussion and research since their discovery nearly 30 years ago. The isolated pentagon rule (IPR) has long served as a guideline for predicting the most stable fullerene cages. More recently, endohedral metallofullerenes have been discovered that violate the IPR. This article presents a systematic, temperature dependent, statistical thermodynamic study of the 24 possible IPR isomers of C... as well as two of the experimentally known non-IPR isomers (51365 and 51383), at several different charges (0, -2, -4, and -6). From the results of this study, we conclude that the Huckel rule is a valid simpler explanation for the stability of fused pentagons in endohedral metallofullerenes. (ProQuest: ... denotes formulae/symbols omitted.)