Ferroelectric liquid crystals V. Chiral alkenyloxyphenyl 4-biphenyl-1-carboxylates

Abstract
Approximately thirty 4-(alkenyloxy)phenyl 4′-alkyl/alkoxy-4-biphenyl-1-carboxylates incorporating a chiral centre at the point of branching of the terminal alkyl/alkoxy chain have been synthesized. The three carbon chains investigated were 2-methylbutyl, 3-methylpentyl and 2-methylbutoxy. The configuration of the chiral centre is (S) in each case. The effect of the alkenyloxy chain length on the liquid crystal transition temperatures of the three homologous series prepared has been studied systematically. Chiral smectic C and chiral nematic mesophases, as well as a smectic A mesophase in several cases, were observed over a wide temperature range for most of the esters prepared.