The Effect on Thermal Nematic Stability of Schiff's Bases Upon Reversal of Terminal Substituents

Nematic liquid crystals have been found to produce dynamic light scattering when subjected to an electric field. (1) This electro-optic effect has stimulated widespread interest in the development of liquid crystals for display devices. It is desirable that the nematic material exhibit the nematic phase around ambient temperature and have a large mesomorphic range. No reported single component system meets these requirements although bis-(4′-n-octyloxybenzal)-2-chloro-1,4-phenylenediamine has a reported 120° nematic range just above ambient temperature (59-179°C). (2)