Electronic structure of dithienopyrrole, dithienotriophene and thionaphtheneindole

Dithienopyrrole (DP), Dithienothiophene (DT) and Thionaphtheneindole (TNI) are electrochromic semiconductor polymers that possess very similar electro nic structure. These materials were synthesized in the middle of the nineti es with the intention to obtain an improvement in the processability of the electrochromic polymers and investigate the mechanism of charge transport in the polymeric net. In this work, we investigated the electronic, conform ational and spectroscopic structure of oligomers formed by the mentioned sy stems. Density of states and wavefunction were calculated to study the cond uction mechanism in the net of these polymers through polaron defect type. We used the semiempirical methods for calculations of electronic structure of the polymers and copolymers coupled with ZINDO/Spectroscopic method to s imulate the behavior of absorption for neutral and charge systems. We adopt ed EHT description for the conformational defects and we investigated the e lectrical conduction as a function of defects concentration.