Alternatively linking fullerene and conjugated polymers

The stereo‐electronic control over bisadditions of conjugated polymers to fullerene (C₆₀) is explored in the formation of alternating copolymers. The chemistry, resulting configuration, and properties of poly(3‐hexylthiophene)‐alt‐C₆₀ copolymers prepared by either classic pyrrolidine ring formation or an atom transfer radical addition are compared. Both routes result in controlled additions of polymers to C₆₀. Extensive macromolecular modeling through PM6 methods indicate that there is no conjugation between P3HT and C₆₀ in the systems studied. This along with 2D‐NMR, AFM, and photovoltaic characterizations of the materials indicate the importance of the structure of the modified C₆₀ and the nature of the linking group between C₆₀ and P3HT segments in determining the morphology of the copolymers in the solid state. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2304–2317, 2009