STUDY THE PROPERTIES OF THERMOTROPIC LIQUID CRYSTALS INDUCED BY HYDROGEN BONDING BETWEEN PYRIDYL- HETEROCYCLIC DERIVATIVES AND BENZOIC ACID,4-HEPTYLOXYBENZOIC ACID OR 4-OCTYLOXYBENZOIC ACID

Synthesis of new derivatives of heterocyclic compounds such as (Triazoles, tetrazole, oxazole and thiadiazole). Liquid crystalline complexes have been obtained from binary mixtures of (4-pyridyl) heterocyclic derivatives with benzoic acid, 4-heptyloxychlorobenzoic acid or 4-octyloxybenzoic acid. The (4-pyridyl) heterocyclic derivatives are not mesomorphic, but the H-bonded complexes are showed droplets nematic texture which is developed from threaded nematic on slow heating. Their liquid crystalline properties were investigated by polarizing optical microscopy.