Use of glucose as a trifunctional building block for chiral liquid crystals

Abstract

Glucose is used as a trifunctional chiral central core in laterally substituted liquid crystals. The synthesis of 1′-(4-O-(4″-octyloxybenzoyl)-2,3,6-trideoxy-β-D-erythrohexopyranosyl)-4′-hexyloxybenzene and its related 6-halogeno derivatives is described as an example for rod-like molecules with small lateral substituents. All the compounds obtained exhibit a cholesteric mesophase. It is shown that there is a correlation between the size of the substituent at the 6-position and the transition temperature from the cholesteric to the isotropic phase. Also, the synthesis of Y-mesogenic compounds containing spaced and/or unspaced substituents in the 4- and 6-positions is described, followed by a qualitative discussion of the results obtained.