Trifluoromethyl derivatives of pentagon-fused C60: 1809C60(CF3)n (n=10, 12, 14, 16)

The carbon cage of buckminsterfullerene I-h-C-60, obeying the Isolated-Pentagon Rule (IPR), can be transformed to the non-IPR C-2v-C-1809(60) cage by a single Stone-Wales rearrangement (SWR) in the course of high-temperature chlorination of C-60 with SbCl5. The following high-temperature trifluoromethylation of the chlorination products with CF3I afforded non-IPR CF3 derivatives, C-1809(60)(CF3)(n). X-ray diffraction studies of C-1809(60)(CF3)(n) (n = 10, 12, 14, 16) revealed that the sites of pentagon-pentagon fusions on the carbon cage are preferentially occupied by CF3 groups. The addition patterns of C-1809(60)(CF3)(n) and related (C60Cln)-C-1809 are compared, demonstrating a prevailing role of pentagon-pentagon fusions in the stability and structural chemistry of these compounds. Further SWR skeletal transformations of C-1809(60) are discussed and compared with the experimental data available.

Automated summary

The research demonstrates the transformation of buckminsterfullerene I-h-C-60 to non-IPR CF3 derivatives through high-temperature chlorination and trifluoromethylation reactions. X-ray diffraction studies reveal the preferential occupation of CF3 groups at the sites of pentagon-pentagon fusions on the carbon cage.