Two Isolated-Pentagon-Rule Isomers C98(110) and C98(111) Isolated as Trifluoromethylfullerenes C98(CF3)22.

The fullerene C98 has 259 topologically possible isomers that obey the isolated-pentagon rule (IPR). In this work, a family of experimentally confirmed IPR isomers of C98 fullerene is extended by the high-performance liquid chromatography isolation and X-ray structural characterization of two trifluoromethyl derivatives, C1-C98(110)(CF3)22 and C1-C98(111)(CF3)22. The carbon cages of isomers Cs-C98(110) and Cs-C98(111) differ by a Stone-Wales rotation of only one C-C bond, which results in very similar addition patterns of 22 CF3 groups in the C98(CF3)22 molecules. The stabilizing substructures in both C98(CF3)22 molecules include six benzenoid rings and four isolated C═C bonds. Both Cs-C98(110) and Cs-C98(111) belong to the isomers of moderate relative stability among altogether seven IPR isomers of C98 fullerene with experimentally confirmed cage structures.