Columnar liquid crystals in oligosaccharide derivatives: I. discotic columnar liquid crystals in cellobiose octadecanoate and cellotriose hendecadecanoate

Cellobiose octadecanoate and cellotriose hendecadecanoate were synthesized and their mesophase properties were studied. Both ester derivatives show enantiotropic mesophases in the temperature region below 100°C. From the observations of microscopic texture and X-ray pattern, the mesophase was found to be of the hexagonal columnar, in which the column is built up by a periodic stacking of the cellobiose or cellotriose skeleton and packed into a two-dimensional hexagonal lattice. The mesophase is thus similar to the hexagonal ordered columnar (Dho) phase in a class of discotics, indicating that cellobiose and cellotriose moieties can work as discotic mesogens.