Synthesis and characterization of biphenyl-based azo liquid crystals and its optical properties: effect of lateral and tail group

Abstract

An azo ester-based biphenyl substituted rod-shaped azo-based material has been synthesized and well-characterized and further studied their mesogenic, optical, and thermal properties. All the synthesized derivatives displayed enantiotropical nematic and SmC phases with good temperature range of mesophase which is further influence by the variation of alkyl chain. The present synthesized derivatives having left terminally substituted phenyl ring by -OR inbuilt with ester azo group and right terminally dodecyloxy tail (-OC₁₂H₂₅) at the right terminal end. The mesomorphism is measured by using POM, DSC, and high-temperature XRD technique, and the photophysical behavior was measured by UV-Vis spectroscopy.

Graphical Abstract

Keywords:

• Azo
• liquid crystal
• nematic
• smectic C
• thermotropic

Acknowledgments

A.T., D.D., V.D., and R.B.P. acknowledge thanks to K.K. Jarodwala Maninagar Science College, Gujarat University, Ahmedabad for providing research lab and other facilities. V.S. also acknowledges thanks to Department of Chemistry, Faculty of Basic and Applied Science, Sirohi, Rajasthan for providing some instrument and lab facility. The authors are also thankful to NFDD Centre Rajkot, IIT Mandi, Sourashtra University, MLSU University, and MNIT Jaipur for providing spectral and other services.