Study of mesomorphism and its relation to molecular structure with special reference to central bridges viz. -COO- and -CH=CH-COO- of the homologous series

GRAPHICAL ABSTRACT

Abstract

Two ester homologous series of mesogens, viz., Methyl-p-(p′-n-alkoxy benzoyloxy) cinnamates (X) and Methyl-p-(p′-n-alkoxy cinnamoyloxy) cinnamates (Y) being structurally similar are discussed. Both (X) and (Y) differ in respect of central bridges linking two phenyl rings. Only enantiotropic nematogenic character is observed without exhibition of any smectic character by all members of series (X) and (Y). Thermal stability of series (X) is relatively low as compared to (Y), but nematogenic mesophase lengths are of reverse order. Solid-nematic/solid-isotropic and nematic-isotropic transition curves in the phase diagrams behave in normal manner.

Keywords:

• Mesogen
• mesophase
• nematic
• smectic

Acknowledgments

The authors thank Dr. Rutesh Shah the Principal of K.K. Shah Jarodwala Maninagar Science College and supporting staff of Chemistry department for valuable cooperation in the work. The authors are also thankful to the authority of Uma laboratory, Vadodra, Vaibhav laboratory, Ahmedabad, and National Salt and Marine research laboratory, Bhavnagar for analysis of samples.