Synthesis and characterization of biphenylethynylbenzene type discotic liquid crystal

Novel discotic liquid crystalline compound containing five rigid biphenyl m oieties was synthesized by coupling reaction using palladium catalyst. Ther mal and optical properties of the obtained compound were examined. We also examined the mesomorphic properties for the mixtures of the synthesized dis k-shaped mesogen doped with 2,4,7-trinitrofluoren-9-on (TNF). The synthesiz ed discotic liquid crystalline compound with a hydroxy group exhibited a sc hlieren texture characteristic of nematic phase, while the mixtures of the disk-shaped compound with TNF displayed a focal conic fan or a broken fan t exture. The charge transfer absorption band of the mixture was observed abo ut 550 nm by UV-vis absorption spectroscopy measurements. Further-more, we examined thermal and optical properties of novel discotic liquid crystallin e polymers prepared by photopolymerization.