Three Isolated-Pentagon-Rule Isomers of C Fullerene Isolated as Trifluoromethyl Derivatives.

The family of experimentally confirmed isolated-pentagon-rule (IPR) isomers of C fullerene is extended by trifluoromethylation of a C fraction of the fullerene soot, high-performance liquid chromatography separation of CF derivatives, and a single-crystal X-ray diffraction study of C(CF) compounds with the use of synchrotron radiation. New cage isomers were revealed in C(94)(CF) and C(182)(CF) compounds, whereas isomer C(181), previously known in the adduct with nickel porphyrinate, was confirmed in C(181)(CF) derivatives. Common and special features of the addition patterns of CF groups on C carbon cages are discussed in more detail. The investigated isomers belong to the most stable -C(181) and slightly less stable -C(94) and -C(182) among the altogether 15 experimentally confirmed IPR isomers of C fullerene.