Rebuilding C 60 : Chlorination-Promoted Transformations of the Buckminsterfullerene into Pentagon-Fused C 60 Derivatives

In recent years, many higher fullerenes that obey the isolated pentagon rule (IPR) were found capable of rearranging into molecules with adjacent pentagons and even with heptagons via chlorination-promoted skeletal transformations. However, the key fullerene, buckminsterfullerene I -C , long seemed insusceptible to such rearrangements. Now we demonstrate that buckminsterfullerene yet can be transformed by chlorination with SbCl at 420-440 °C and report X-ray structures for the thus-obtained library of non-IPR derivatives. The most remarkable of them are non-IPR C Cl and C Cl with fundamentally rearranged carbon skeletons featuring, respectively, four and five fused pentagon pairs (FPPs). Further high-temperature trifluoromethylation of the chlorinated mixture afforded additional non-IPR derivatives C (CF ) and C (CF ) , both with two FPPs, and a nonclassical C (CF ) F with a heptagon, two FPPs, and a fully fused pentagon triple. We discuss the general features of the addition patterns in the new non-IPR compounds and probable pathways of their formation via successive Stone-Wales rearrangements.