The EPR spectra of a series of perfluoroalkyl-C-60 radicals F3-nC(CF3)(n)C-60 (3 greater than or equal to n greater than or equal to 0) are described and discussed. It is concluded that the enthalpy barrier hindering rotation about the C-C-60 bond in CF3C60 is ca. 7 kcal/mol and that in the nonrotating configuration its F-19 nuclei have hyperfine interactions of opposite sign. On the EPR time scale, CF3CF2C60 is locked into the symmetric configuration. The equilibrium configuration of (CF3)(2)CFC60 is asymmetric, and the barrier between its two enantiomeric forms is ca. 3.5 kcal/mol. In the case of (CF3)(3)CC60, the CF3 groups liberate in synchrony with rotation about the C-C-60 bond.