67. Ferroelectric Liquid Crystals. Laterally Substituted Phenyl Benzoates Incorporating a trans-1,4-Disubstituted Cyclohexane Ring.

Article abstract of DOI:10.1002/hlca.19890720319

About 65 diverse phenyl benzoates incorporating a trans-1,4-disubstituted cyclohexane ring and at least one lateral substituent have been synthesised.The dependence of the liquid-crystal transition temperatures of these materials on various lateral substituents (F, Cl, CN, and Br) in different positions of the esters has been investigated systematically.The influence of up to four F-atoms in various positions of a standard ester has been thoroughly studied and the optimum combination for a broad smectic C mesomorphic range established.In consequence, three homologous series incorporating the 4-alkoxy-2,3-difluorobenzoic-acid moiety were prepared.An additional C=C bond was introduced into the alkyl chain attached to the cyclohexane ring of some of these esters and the resulting modifications of the transition temperatures determined.Three ester series incorporating a lateral substituent and the optically active (+)-(S)-(1-methylphenyl)oxy substituent have also been synthesised, and similar effects have been observed.These materials can be used as important components of commercial chiral smectic C mixtures for electro-optic display device applications.