Host-guest complexation: a convenient route to polybithiophene composites by electrosynthesis in aqueous media. Synthesis and characterization of a new material containing cyclodextrins

An inclusion compound with hydroxypropyl-beta-cyclodextrin (HP beta CD) as host molecule has been used to electropolymerize bithiophene in aqueous medium. The complexation of bithiophene by HP beta CD has been investigated by fluorescence, showing that BT molecules are tightly bound to cyclodextrin hosts. The electrochemical behaviour of this inclusion compound is irreversible in aqueous solution in the presence of HP beta CD. The anodic electropolymerization of the BT-HP beta CD complex has been performed in aqueous medium under galvanostatic or potentiodynamic conditions. Characterization of the deposited films supports the notion that polybithiophene (PBT) composites are formed. Although they show the usual features of PBT, the structure of the films appears to be considerably modified by the presence of cyclodextrins within the material but not grafted onto the polymeric backbone.