Electroactive Mesomorphic Side-Chain Polymers from Cationic Polymerization of Polar End-Group Liquid Crystal Monomers

We report preliminary results dealing with the preparation of highly ordered side-chain polymers from a special class of mesogenic nitriles, R‒C≡N in which the cyano group is electrically and mechanically decoupled from a rigid aromatic core. The polymerization process consists of heating the complexes formed between R‒C≡N and a transition-metal halide, such as ZnCl2. These complexes form highly ordered smectic phases and their transition temperatures make it possible for polymerization to occur within an oriented mesophase phase. In the polymers, the conjugated main chain induces an electroactive character, which allows the formation of a conducting system upon doping. We specially stress the possibility of obtaining crystalline and/or mesomorphic properties with appropriate R groups.