Grafting polymers onto C-60 via an atom transfer reaction

Halogen terminated PS chains of low polydispersity, prepared by atom transfer radical polymerization (ATRP), can be converted to macro-radicals using an atom transfer reaction and so attached to C,,. Depending on the stoichiometry PS-Br/ C-60 2 or 4 chains are grafted onto the fullerene. We propose a mechanism which can explain that no adducts with an odd number of arms are formed.