| Abstract
| - The electrochemical polymerization of bis(2-thienyl)methanes carrying substituents eitheron the methylene carbon or on the thiophene rings is reported. Poly(dithienylenemethylene)s are formedwhich undergo in-situ dehydrogenation to poly(dithienylenemethine)s. Bis(3,4-ethylenedioxythienyl)methane gave a very low-gap material (0.4 V onset-based bandgap). This value is much lower than thosepreviously reported for chemically prepared materials having the same conjugated backbone but carryingdifferent substituents. The unsubstituted bis(2-thienyl)methane gives a similar low-gap polymer as well,but overoxidation and probably misjunction defects are present. No polymer was formed in the case of2,2‘-bis(2-thienyl)propane, for which the possibility of producing a conjugated polymer is precluded bythe lack of at least one hydrogen atom on the carbon bridging the thiophene units. Full electrochemicaland optical characterization data for the polymers are reported, and the polymerization and p- andn-doping processes are discussed.
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