Polymers containing rigid benzodithiophene repeating unit with extended electron delocalization

Abstract

Polymers containing a fused benzodithiophene core with phenylethynyl substituents were prepared. The parent poly[4,8-bis(4-pentylphenylethynyl)benzo[1,2-b:4,5-b']dithiophene] was prepared by a Stille coupling. Copolymers with the new core were also obtained by Stille coupling with dibrominated fluorene and carbazole monomers. The obtained polymers had a lower band gap as compared to the related benzodithiophene cores due to the extended electron conjugation. The polymers were also highly fluorescent as observed by high quantum yields.