Polaron-bipolaron model of conducting polymers

The conductivity of the conducting polymers in the oxidized state is not as easy to explain. The main feature of the conducting polymers is the chain structure of alternating double bonds. The structure can change from a benzoic to quinoidic form. For the most important conducting polymers like polythiophene, polypyrrole, and polyaniline, the two structures 

Further details about the oxidized state were obtained from experiments with hexa-thienyl by Gamier et alP Formation of dimers was observed in these experiments with oligomers. Fleinze et al. found evidence for the formation of a a-dimer. Dunsch et al. were able to experimentally confirm the formation of tt-dimers.  

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