Pentamethylated derivatives of [60]fullerene: X-ray structure of the C60Me5H and ESR spectroscopy evidence for the stable radical radical dotC60Me5

Single-crystal X-ray study of 6,9,12,15,18-pentamethyl-1,6,9,12,15,18-hexahydro(C60-Ih)[5,6]fullerene (C60Me5H) has been reported. In crystal packing, the stacking self-organization of molecules is realized. It is concluded that the formation of such polar columns is a general rule for crystals of C60R5H independent of the nature of the R group. An ESR spectrum of the stable fullerenyl radical of the cyclopentadienyl-type, radical dotC60Me5, was observed in a sample of the pentamethylated[60]fullerene. Rotation of methyl groups around C–C bonds is restricted on the ESR scale time and therefore protons within each methyl group are non-equivalent.