Electrochemically Induced Dimerization of -C(CF) Trifluoromethylated Fullerene.

We report a comprehensive study of a novel isomer of C(CF), -C(CF), whose electrochemical behavior differs from most of the other trifluoromethylated fullerenes. The addition pattern of -C(CF) is established by means of F-F COSY NMR spectroscopy and DFT calculations. Like -C(CF), the new isomer -C(CF) undergoes dimerization to the [C(CF)] upon single-electron reduction. The electrochemical observations are supported by the DFT calculations of dimerization energy and the temperature dependence of the CW X-band EPR spectroscopy data. Experimentally determined dimerization energies of -C(CF) and -C(CF) in solution are ca -8 and -26 kJ mol, respectively, in good correspondence with DFT data.