Alkyl side-chain branching point effects in thieno[3,4- c ]pyrrole-4,6-dione copolymers

Abstract

A novel and efficient route to thieno[3,4-c]pyrrole-4,6-dione (TPD) facilitating late-stage alkylation is presented. Four copolymers with alkylated bithiophene (2T) are synthesised, with different TPD N−alkyl side-chain branching points. The effect of steric bulk on solid-state properties is investigated (UV–VIS, differential scanning calorimetry, X-ray diffraction) and C1-branching found to increase crystallinity and solid-state packing in TPD-2T.