Radical Reactions of C 60

Abstract
Photochemically generated benzyl radicals react with C60 producing radical and nonradical adducts Rn C60 (R = C6H5CH2) with n = 1 to at least 15. The radical adducts with n = 3 and 5 are stable above 50°C and have been identified by electron spin resonance (ESR) spectroscopy as the allylic R3C60. (3) and cyclopentadienyl R5C60. (5) radicals. The unpaired electrons are highly localized on the C60 surface. The extraordinary stability of these radicals can be attributed to the steric protection of the surface radical sites by the surrounding benzyl substituents. Photochemically generated methyl radicals also add readily to C60. Mass spectrometric analyses show the formation of (CH3)nC60 with n = 1 to at least 34.