In this work, two kinds of novel thiophene-aniline polymers, were studied through theoretical protocols in order to find new insights about the polymerization mechanism, the chemical structure and optical properties exhibited by this kind of conducting materials. The dual descriptor—a local reactivity descriptor derived from conceptual density functional theory— and the condensed electrophilic Fukui index were used to describe the most probable sites of polymerization. Frontier orbitals energies were calculated to predict the band gap of both polymeric films. All results demonstrated how theoretical protocols help in the understanding of chemical polymerization mechanism and in the prediction of relevant properties, which can accelerate the synthesis process of new monomers