A theoretical analysis of polarons and bipolarons in poly(OSO) is presented
. Singly and doubly oxidized oligomers (3 <n < 15), whose all rings are lin
ked at the syn or anti-forms, are used as model. The PM3 calculations showe
d that the single positive charge is concentrated around linked furan rings
. Furthermore, a quinoid structure extends over 6 (oxidized) and 8 (doubly
oxidized) rings. The W-vis absorption spectra, simulated with the aid of th
e ZINDO/S-CI method, indicated two and one sub-gap absorption peaks for the
syn and anti-conformation oligomers, respectively. These results might pro
vide a coherent interpretation of the experimental spectra of doped polyfur
an and polythiophene.