Synthesis, characterization, and properties of a new thiophene-benzobisthiazole copolymer

Synthesis, characterization, and properties of a new thiophene-benzobisthiazole copolymer

  Stille coupling reaction of 4,8-dibromo-2,6-dihexyl-benzo[1,2-d:4,5-d"]bisthiazole and 2,5-bis(trimethylstannyl)thiophene afford a new conjugated conducting copolymer 1. The polymer was completely soluble in common organic solvents. The electrical conductivity of the polymer is at about 3.8×10<SUP>-1</SUP> S/㎝. The UV？vis spectra of the polymer in a chloroform solution and in a spin-cast film on a piece of glass show π？π<SUP>*</SUP> absorption bands (λ<SUB>max</SUB>) of 460 ㎚ and 538 ㎚, respectively. The 78 ㎚ red shift of the λ<SUB>max</SUB> of the polymer in the film, in comparison to that observed for the polymer in chloroform, possibly indicates much more planarization and aggregates formation due to the π electron stacking in terms of inter-chain characteristics in the solid state. The structure of the polymer has been compared with that of compound 3 as model compound. Rationalizations are presented for optical properties of the polymer in relation to polymer structure.