Nitrophenyl Liquid Crystals with Intramolecular Hydrogen-Bonding in the Mesogenic Core

A liquid crystalline homologous series of 4-nitrophenyl-4′-alkoxyphenyl diazene and their 2′-hydroxy analogs were synthesized, and their mesogenic properties were studied. The formation of intramolecular hydrogen bonding in the 2′-hydroxy analog series increased the rigidity of the mesogenic core and enhances the ranges of the liquid crystalline phases.