A homologous series of azoester mesogens, 4-(4’-n-alkoxy benzoyloxy)-3, 5-dichloro phenylazo-4’’-methyl benzenes of twelve homologues has been synthesized. The first three and last two member of the series is non-mesomorphic. Mesomorphism commences from fourth homologue and ends to twelfth homologue. Fifth to tenth homologues are enantiotropic nematic, while fourth and twelfth homologue is monotropic nematic. Thus, totally seven member of the titled homologous series are mesomorphic in nature. Smectic mesophase does not occur in any homologue of the series even in the monotropic condition. The usual odd-even effect is observed in nematic-isotropic transition curve. The average thermal stability and liquid crystalline properties are compared with structurally identical homologous series. Analytical data support the structures of molecules. Transition temperatures of homologues are observed through hot stage polarizing microscope. Texture of the homologues is of threaded type nematogens.
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