Reactions of photoexcited C-60 with weak organic acids. Novel method for the derivatization of fullerenes

Pyrex-filtered irradiation of C-60 solutions in liquid diphenylmethane in t he absence of oxygen is shown to result in Ph,CH. radicals, which further r eact with the electron-deficient C-60 to give Ph2CH-C60Hn (n = 1, 3, 5). Th e fullerene ground state to C-3(60) transition is suggested to be accompani ed by the increase of the fullerene solvation affecting thus the acidity of methylene hydrogens in Ph2CH2 as well as the feasibility of their dissocia tion. Also, photolysis of C-60 solutions in weakly acidic phenylacetylene i s shown to lead to the addition of a varying number of phenylethinyl groups to the fullerene core. (C) 2000 Elsevier Science B.V. All rights reserved.