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 C60 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 C60‐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.