The dependence of mesomorphic behaviour on the extent of hydrogen-bonding in sugar derived polyols

The thermotropic liquid crystalline properties of a variety of chiral and racemic dodecyloxy substituted polyols derived from carbohydrates were investigated as a function of the number of hydroxyl groups associated with the polyol unit. It was found that all of the materials exhibited smectic A* phases, and that the clearing points increased monotonically with the number of hydroxyl groups. The linear increase was found to be independent of stereochemical structure and the degree of optical purity. A model suggesting that the smectic A* phase has an internal microphase separated structure can be used to account for these observations.