Synthesis and properties of poly(2-ethynylpyridinium bromide) having side-chain liquid crystalline moieties

Abstract Novel conjugated polymer having side chain liquid crystalline moieties was easily synthesized by the direct polymerization of 2-ethynylpyridine with the corresponding alkyl bromide having a liquid crystalline moiety, 4-{4′-{10′′-bromodecyl}oxyphenyl}azobenzoic acid. The polymerization proceeded well to give the resulting polymer in moderate yields. The polymer structure was characterized by various instrumental methods to have conjugated polymer system with liquid crystalline moieties. The photoluminescence spectrum of the polymer film shows that the photoluminescence peak is located at 430 and 454 nm corresponding to the photon energy of 2.80 and 2.66 eV. A needle shape of texture, which is a typical optical texture of smectic phase, was observed.