Synthesis and Characterization of Fluorene-Based Conjugated Polymers Containing Thiophene Derivatives in Main Chain

Abstract

Three novel alternating copolymers containing 9,9-dioctylfluorene and thiophene derivatives, poly[(9,9-dioctylfluorene-2,7-diyl)-alt-(4,4'-bis(3 ''-hexyl-2 '' thienyl)-biphenyl-5 '',5 ''-diyl)] (P1), poly[(9,9-dioctylfluorene-2,7-diyl)-alt-(5,5'-bis (3 ''-hexyl-2 '' thienyl)-2,2'-bithiophenyl-5 '',5 ''-diyl)] (P2), and poly[(9,9-dioctylfluorene-2,7-diyl)-alt-(5,5'-bis(3 ''-hexyl-2 '' thienyl)-2,2'-biselenophenyl-5 '',5 ''-diyl)] (P3) were synthesized by a palladium-catalyzed Suzuki polymerization. The synthesis, thermal stability, as well as the optical and electrochemical properties of these polymers are systematically investigated. The polymers were thermally stable up to 400 degrees C, and readily soluble in common organic solvent. The absorption and emission maxima of the copolymers varied according to the type of incorporated aromatic group (thiophene, selenophene, or phenylene).