Radical adducts of fullerenes C[sub 60] and C[sub 70] studied by laser flash photolysis and pulse radiolysis

The reaction of organic radicals (R[sup [sm bullet]] = benzyl, tert-butyl, trichloromethyl) with C[sub 60] and C[sub 70] has been investigated using laser flash photolysis and pulse radiolysis techniques. The alkyl radicals are very reactive toward fullerenes and form radical adducts, (RC[sub 60])[sup [sm bullet]] and (RC[sub 70])[sup [sm bullet]]. The difference absorption spectrum of (RC[sub 60][sup [sm bullet]]) exhibits broad absorption in the visible, while that of (RC[sub 70])[sup [sm bullet]] exhibits bleaching of absorption in the region 440-560 nm. The rate constants for the reaction of these radicals with fullerenes are in the range of 10[sup 8] M[sup [minus]1] s[sup [minus]1] for dichloromethyl to diffusion controlled for tert-butyl radicals. 30 refs., 6 figs., 1 tab.