Alternatively linking fullerene and conjugated polymers

Abstract

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.