Poly (4,7-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2,1,3-benzothiadiazole) (PBEDT) a novel low – band – gap polymer has been synthesised by electro-polymerisation of a trimer composed of precursors ethylenedioxythiophene combined with 2,1,3-benzothiadiazole. The Ultraviolet–visible (UV-V) is spectrum of the trimer in chloroform solution gave two absorption bands with peaks at 323 nm and another at 482 nm with an onset absorbance at 580 nm. Cyclic voltammetric data showed that the trimer oxidises at low potential and further cycling resulted in its polymerisation. This was evident by the growth of current in the region of – 0.5 and 0.5 eV forming a peak around – 0.3 eV as polymer layers begin to deposit on the surface of the Pt. electrode forming an insoluble polymer film.

Keywords: Benzothiadiazole, 3,4-ethylenedioxythiophene (EDOT), conjugated trimer, intra-molecular charge transfer, electro-polymerisation.