Liquid Crystal Phases Exhibited by Some Monosaccharides

Abstract

Recently some mono-alkylated derivatives of β-D-glucopyranoside and thio-α-D-mannopyranoside were shown to exhibit liquid crystal properties. The structure of the phase produced by these materials was described as being of a layered smectic type. However, a full classification of the phase was not given. The present investigation defines the phase as smectic A with a bilayer structuring. The lamellar spacings previously found for the phase agree with calculated values for a bilayer ordering in which the carbohydrate moieties overlap to produce an extensively hydrogen bonded structure. The phase was found to be immiscible with the A phases of conventional smectogens because the hydrogen bonding necessary for phase formation is disrupted in binary mixtures.