Thieno-, Furo-, and Selenopheno[3,4-c]pyrrole-4,6-dione Copolymers: Effect of the Heteroatom on the Electrooptical Properties

New push pull conjugated polymers based on furo[3,4-c]pyrrole-4,6-dione (FPD) and selenopheno[3,4-c]pyrrole-4,6-dione (SePD) have been synthesized and compared with their thieno[3,4-c]pyrrole-4,6-dione (TPD) analogues to investigate the effects of the heteroatom on the electrooptical properties. The copolymers were synthesized using either Stile cross-coupling or direct heteroarylation polymerization (DHAP), the latter method giving high molecular weights. Hypsochromic shifts of the band gaps were observed for FPD-based copolymers (sulfur substituted by oxygen) while small bathochromic shift was observed for SePD (sulfur substituted by selenium) when compared to its TPD analogue. These two new classes of conjugated polymers exhibit electrooptical properties that could lead to interesting bulk heterojunction plastic solar cells.