Synthesis and Mesomorphism of Novel Liquid Crystalline: 4-(4′-n-Alkoxy Benzoyloxy)-Naphthylazo-4″-Chlorobenzenes

Abstract

A new azoester homologous series 4-(4′-n-alkoxy benzoyloxy)-naphthylazo-4″-chlorobenzenes is synthesized. Its first and second homologues are nonmesomorphic, while the rest of the homologues are mesomorphic, showing enantiotropic nematic behavior. Smectic character is totally absent. An odd–even effect is observed in the nematic–isotropic transition curve with alternation in transition temperatures. The average thermal stability and liquid crystal behavior for the nematic mesophase are compared with structurally similar homologous series. Analytical data support the structures of the molecules. The texture of the nematic mesophase is of threaded type. Transition temperatures are observed through hot-stage polarizing microscope. Analytical data support the structures.

Keywords:

• Azomesogens
• mesomorphism
• nematic
• smectic

Acknowledgments

The authors acknowledge and thank the head and teaching staff of Applied Chemistry Department, Faculty of Technology and Engineering, M. S. University, Vadodara, Gujarat, India, for their valuable cooperation in the work. They are also thankful to CSMCRI, Bhavnagar, Gujarat, India, for the analysis of sample.