Synthesis and characterization of a new yellow-green light-emitting polymer - Poly{1,4-bis[3-(4′-butylphenyl)thienyl]-2,5-di(2′-ethylhexyloxy) phenylene

A novel conjugated polymer (PBBPTDEHP), which has a regioregular structure, was successfully synthesized in chloroform using FeCl₃ as the oxidizing reagent. The polymer shows good thermal stability and can be easily dissolved in xylene, chloroform, tetrahydrofuran (THF) and other common organic solvents. Due to the symmetry of the monomer, the polymer formed contains no head-head configurational isomers and has high regioregular structure. The structure and the purity of the polymer were characterized by FTIR, ¹H NMR, ¹³C NMR, MS, and elemental analysis. The absorption edge of the UV-vis spectrum of the film sample indicates that the band gap of the polymer is 2.48 eV, which corresponds to yellow-green emission. The polymer shows very similar electrochemical properties to polythiophenes while retaining the synthetic flexibility for substitution found in phenylene. All of the results indicate that the polymer is a promising yellow-green emissive material for application in light-emitting devices (LEDs).