ELECTROCHEMICAL OXIDATIVE COUPLING OF CYANO-SUBSTITUTED OLIGOTHIOPHENES

Conjugated bi- and terthiophenes have been substituted by cyano groups on several positions of the oligothiophene backbone. Their ability to form, after oxidation, longer oligothiophenes has been analyzed by el ectropolymerization. Whereas cyano-substituted bithiophenes and dicyan oterthiophenes were found to be unable to give longer products, monocy anoterthiophenes could be dimerized, leading to disubstituted sexithio phene derivatives. The electrochemical and optical behavior of the thr ee new electrosynthesized dicyanosexithiophenes were studied and compa red with those of shorter substituted cyano-oligomers.