Cholesteric carbohydrate liquid crystals incorporating an intact glucopyranose moiety

Recently, the first monosaccharide derivatives containing a fully intact monosaccharide and two vicinal OH-groups which display thermotropic chiral mesophases were synthesized. These liquid crystals have a rigid core, with a trans-decalin-like skeleton incorporating the D-glucopyranose ring, substituted with an alkoxylated polarizable aromatic group, e.g. a phenyl 4-octyloxybenzoate, on one side and an alkoxyphenyl group at the anomeric centre. On the basis of the focal-conic fan-like texture displayed and the existence of a blue phase in the UV, we expected the cholesteric helix to have a very short pitch. The compounds possessed an exceptionally high helical twisting power. Extrapolation of these data to dopant concentrations of 100 % also indicates a very short pitch (30 -90 nm).