Structure-property relations in donor-acceptor-donor type benzimidazole containing conjugated polymers

In order to gain deeper insight about structure-property relations properties, two novel donor-acceptor-donor type monomers were studied. 4'-Tert-butyl-4,7-di(thiophen-2-yl)spiro[benzo[d]imidazole-2,1'-cyclohexane] and 4,7di(2,2'-bithiophen-5-yl)-4'-tert-butylspiro[benzo[d]imidazole-2,1'-cyclohexane] were synthesized and electrochemically polymerized. Electrochemical and optical properties of the polymers were investigated via cyclic voltammetry and UV-Vis-NIR spectroscopy techniques. It was found that changing donor unit from thiophene to bithiophene results in a drastic change in optical and electrochemical properties, especially in optical contrast