The chemical, electrochemical synthesis and properties of poly[(4-decylthiophene-2,5-diyl)(2,2′-biphenyl)(4-decylthiophene-2,5 -diyl)]

A novel blue-emitting conjugated polymer, poly[(4-decylthiophene-2,5-diyl)(2,2′-biphenyl) (4-decylthiophene-2,5-diyl)] (PDTBPDT), has been synthesized via the reductive coupling polymerization using nickel(0) as the catalyst in place of FeCl₃-oxidative polymerization. The chemical structure of the polymer is verified by ¹H and ¹³C NMR, FT-IR and elemental analysis. The polymer exhibits good thermal stability and solubility in common organic solvents. The investigation of its optical properties exhibited that its conjugation efficiency was controlled by the twisted biphenyl group and head-to-head connection between adjacent thiophene rings, and resulted in blue photoluminescence. Its electrochemical property showed that the biphenyl group introduced into the main chain could adjust the HOMO and LUMO energy levels of the polymer. The electrochemical polymerization of the polymer is also investigated.