Synthesis of Liquid Crystals with Lateral Methyl Group and Study of Their Mesomorphic Properties

Abstract

Two new homologous series consisting of central azo and ester linkage and methyl groups at the central as well as terminal benzene rings are synthesized and their mesomorphic properties are studied. Between these two series; Series I has lateral methyl group on terminal benzene ring where as series II has lateral methyl groups at central as well as terminal benzene cores. All the homologues of series I and II are mesogenic in nature; series I exhibits nematic phase from C1 to C14 members whereas C16 member shows smectic C mesophase alongwith nematic mesophase on the other hand all the members of series II are nematogenic in nature. The nematic phase of the series I and II shows marble/schlieren texture and the smectic phase shows schlieren texture of smectic C variety. The mesomorphic properties of both the series are compared with each other and also with other structurally related series to evaluate the effect of lateral methyl group at central as well as terminal benzene core on mesomorphism.

Keywords:

• Azo-ester mesogen
• homologous series
• lateral methyl group
• mesomorphism
• nematic
• smectic C

Acknowledgments

The authors are thankful to the Heads, Prof. Deota and Prof. Murthy of the Applied Chemistry Department, Faculty of Technology and Engineering, The M.S. University of Baroda, Vadodara, for providing the laboratory as well as analytical instruments facilities.