Selective Addition of Secondary Amines to C60: Formation of Penta- and Hexaamino[60]fullerenes

Secondary amines are well-known to add to [60]­fullerene to form the tetraamino epoxy adduct C60(O)­(NR1R2)4 under both photolysis and thermal conditions in the presence of oxygen. We have now found that pentaamino hydroxyl adduct C60(OH)­(NR1R2)5 and hexaamino adduct C60(NR1R2)6 can be formed as the major products in the dark in the presence of oxygen. Key steps of the reaction mechanism probably involve repeated oxygen oxidation of the radical ion pair between fullerene and amines.