Novel high birefringent isothiocyanates based on quaterphenyl and phenylethynyltolane molecular cores

Abstract

We report the synthesis of new laterally alkyl substituted high birefringent quaterphenyl and phenylethynyltolane liquid crystals with isothiocyanate terminal group. The thermal and optical properties such as birefringence are measured and discussed based on their molecular structures. The compounds exhibit birefringence (Δn) in the range of 0.44–0.63, and are expected to be appropriate components of high birefringent nematic mixtures for various applications.

Keywords:

• high birefringence
• nematic
• isothiocyanate
• tolane derivative

Acknowledgement

This work was supported by the Military University of Technology Grant 08-714.

Notes

1. 1,4-bis[(4-butylphenyl)ethynyl]-2-ethylbenzene, T_Cr–N = 29.5°C, T_N-I = 121.0°C, Δn = 0.37 (633 nm, 25°C).