Investigation of the mesogenic behavior of alkoxy and fluorine tail terminated alkoxy nitrobiphenyls for chemoresponsive liquid crystals

Liquid crystal properties of compounds with a variety of polar terminal groups including cyano, fluoro, isothiocyanato, etc., were studied well, however, not enough attention was given to nitro terminal compounds. In this work, a series of fluorine tail terminated alkoxy nitrobiphenyl compounds were synthesised and their mesogenic properties were analysed. In addition, the simple alkoxy nitrobiphenyl compounds were synthesised and analysed in order to compare them with fluoro-alkoxy nitrobiphenyl compounds and for binary mixture analysis. Fluorine tail termination to the alkoxy chain does suppress the smectic phase that was observed for the simple alkoxy nitrobiphenyl compounds with longer chains. Fluorine tail terminated alkoxy nitrobiphenyl compounds with longer chains (C7-C10) show monotropic nematic phase around ambient temperature and supercooling properties and these compounds are useful for a binary mixture analysis. Moreover, computation and experimental analyses of the alkoxy nitrobiphenyl compounds were performed to investigate the potential use of these nitro terminal compounds as chemoresponsive liquid crystal materials.