Synthesis and polymerization of 2,2'-bithiophenes substituted with π-conjugated arms

Abstract

A variety of 2,2′-bithiophene derivatives with different π-conjugated arms at the 3,3′-positions have been synthesized and evaluated as suitable building blocks for the preparation of functional conjugated polymers. Polymerizations have been carried out through either Horner-Wadsworth-Emmons (HWE) or Stille cross coupling reactions with appropriate comonomers. Whereas the polymerization of 5,5′-diformyl- and 5,5′-dibromo-2,2′-bithiophenes did not extend beyond a small number of monomer units, 5,5′-bis(4-formylphenyl)-2,2′-bithiophenes formed polymers with high molecular weights, narrow polydispersity and good thermal stability. A preliminary study of the UV and photoluminescence properties of the prepared compounds is also presented.