Optical and static dielectric properties of two nematogenic isothiocyanato-tolane compounds: a comparative study

Abstract

The optical and dielectric properties of two laterally monofluorinated isothiocyanato-tolane nematogens, which differ only on the position of fluorine atom in the core, have been studied as a function of temperature. A four-parameter model is validated by fitting the experimentally measured values of refractive indices, birefringence and average refractive indices of the compounds with the theoretical ones. The position of fluorine substituent in the rigid core have been found to have little effect on optical birefringence, but pronounced effect on dielectric anisotropy.

Keywords:

• Dielectric anisotropy
• four parameter model
• nematogen
• optical birefringence

Acknowledgments

We are grateful to Prof. R. Dabrowski, Military University of Technology, Poland for kindly donating us the liquid crystalline compounds used in this work.

Additional information

Funding

This work is supported by UGC Minor Research Project No.F.5-209/2015-16/MRP/NERO/855.