Syntheses and properties of conjugated polymers with cumulenic bond in themain chain

Syntheses of novel n-conjugated polymers with a cumulene unit such as allen e and butatriene in the main chain were attempted in order to investigate p roperties of cumulene moiety in the conjugated polymer chain. Electroreduct ive polycondensation of tetraiodoallene afforded an ill-characterized trans parent dark filmy product. Polymerization of 1,4-bis(4-bromophenyl)-1,4-dip henylbutatriene by dehydrohalogenative polymerization with Ni(cod), gave a soluble red polymer having a semiconducting property was obtained without d ecomposition of the cumulenic bond, which was characterized by IR, Raman, a nd UV-Vis spectroscopy. Oxidative pol condensation of 1,4-bis(4-ethynylphen yl)-1,4-diphenylbutatriene with a Cu-TMEDA catalyst gave a conjugated polym er with butatriene and butadiyne segments.