Optical properties of conjugated copolymer incorporating thienylene-dioctyloxyphenyle-thienylene and bipyridine units prepared by Stille coupling reactions in the ground and lowest singlet excited states were calculated with Time Dependent Density Functional Theory (TD-DFT), CIS/3-21G*, and semiempirical (ZINDO) methods. The complementarities and the good agreement between theoretical and experimental results have permitted us to describe electronic structure and to predict a correlation between structure and properties of this new copolymer. Then, on the basis of these results, we show that this copolymer could be exploited as an active layer in optoelectronic devices. (c) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012