Stabilization and Induction of Liquid Crystalline Phases by Hydrogen Bonds

The formation of induced liquid crystalline phases by hydrogen bonds between nitrogen in pyridine derivatives (P) and the OH group in various carboxylic acids (A) was investigated by phase diagrams, X-ray studies and dielectric measurements. In mixtures with mono- and bifunctional pyridines respectively, increasing clearing temperatures and induced smectic A phases were found. Bifunctional non-liquid crystalline acids as components in mixtures with bifunctional pyridine derivatives give only compounds in the solid state. The data are interpreted by the formation of stable associate A x P y which acts as a new compound.