Synthesis and Mesomorphism of Novel Liquid-Crystalline Isobutyl-p-(p′-n-Alkoxy Cinnamoyloxy) Cinnamates

Abstract

A new homologous series viz. Isobutyl-p-(p′-n-alkoxy cinnamoyloxy) cinnamates consisting of 11 homologs has been synthesized with an isobutyl cinnamate end group and a further cinnamate moiety as a linking group. The methyl to butyl homologs are nonmesomorphic, and the pentyl to hexadecyl derivatives are enantiotropic nematogens without exhibition of any smectic phases. The average thermal stability for the nematic phase is 138.1°C with a middle ordered melting point. The structures of the novel materials were confirmed by spectroscopic techniques. The liquid crystal phase type was determined by optical polarizing microscopy and all textures are of the threaded type. The mesomorphic behavior of the series is compared with a structurally similar homologous series.

Keywords:

• Liquid crystals
• mesomorphic
• nematic

Acknowledgment

The authors thank the head, chemistry department, Dr. N. N. Vyas and his colleague Dr. M. L. Chauhan for their valuable co-operation in the work. The authors are also thankful to the Authority of Uma laboratory, Vadodara, Vaibhav laboratory, Ahmedabad, and National Salt and Marine Research institute, Bhavnagar for analysis of samples.