Interest in conductive organic polymers has considerably increased since th
e discovery in 1977 of the doped molecule polyacetylene. Recently, polymers
of dithienopyrrole (DP), dithienothiophene (DT) and thionaphtheneindole (T
NI) have been synthesized electrochemically showing for several monomer rat
ios good electrochromic and conducting characteristics.
The aim of this paper is to investigate theoretically the electrical and op
tical properties of the above mentioned polymers. Therefore, we have perfor
med a conformational structure study followed by electronic structure calcu
lations. Also we present a spectroscopic study for oligomers built with the
monomers of these materials.
In our calculations we utilized the semiempirical method AM1 for the electr
onic and geometric simulation of the polymers. Optical absorption spectra f
or neutral and charged systems were calculated using the INDO/S-CI method.
All three systems showed similar electronic behavior but significant differ
ences can be seen on the TNI monomer optical spectra. Our results are in go
od agreement with the experimental ones.