Polythiophene‐graft‐Styrene and Polythiophene‐graft‐(Styrene‐graft‐C₆₀) Copolymers

Poly(3‐hexylthiophene) was quantitatively brominated and subsequently used in the Suzuki cross‐coupling with a boronic ester of a nitroxide to form a macroinitiator bearing a TEMPO group on each thienyl ring. This macroinitiator initiated the nitroxide‐mediated radical polymerization of styrene and 4‐chloromethylstyrene (CMS), and subsequently reacted with C 60 to yield soluble graft, rod‐coil polymers. Films of the polymers display a bi‐continuous phase structure as revealed by AFM. Similar polymers, in which only a fraction of the thienyl units boasted C 60 ‐bearing side chains, displayed optical properties representative of extensive π ‐delocalization. The potential application of this methodology for the synthesis of graft polymers for photovoltaic devices is discussed. magnified image