Novel chiral liquid crystals derived from (R)-2-(4-hydroxyphenoxy)propan-1-ol

Abstract

The thermotropic liquid-crystalline behaviour of a number of (R)- and (R,S)-2-(4-substituted-phenoxy)-1-alkoxy propanes has been examined and related to changes in the nature of the mesogenic core and the terminal alkoxy substituent. Compounds containing a 4′-pentylbiphenyl-4-carbonyloxy core were generally found to display smectic A and the more ordered crystal B mesophases; in contrast the 4-(4-trans-pentylcyclohexyl)benzoyloxy-derived series showed chiral nematic and Blue phases in addition to the smectic A and crystal B phases. Furthermore, the high optical purity of these materials was demonstrated by use of ¹H NMR and chiral shift reagent techniques, and confirms the stability of the chiral centre towards racemization.