5,6-Difluoro-1H-indene derivatives: novel core structure of liquid crystals with high Δn and Δϵ

Abstract

We have designed and synthesised the novel liquid crystal core structure, 2-phenyl-5,6-difluoro-1H-indene, based on preliminary calculation of the theoretical values of birefringence (Δn) and dielectric anisotropy (Δϵ). These compounds have been proved to have high nematic–isotropic transition temperature, and high optical anisotropy values with long molecular conjugation length. The introduction of lateral fluorine atoms into the 2-phenyl group of 5,6-difluoro-1H-indene derivatives leads to low viscosity and high dielectric anisotropy.

Keywords:

• liquid crystal
• 5,6-difluoro-1H-indene derivatives
• high nematic–isotropic liquid crystals
• high optical anisotropy liquid crystals
• high dielectric anisotropy liquid crystals

Acknowledgements

We thank Mr. K. Kitajima and Ms. T. Watanabe in AGC Seimi Chemical for the physical evaluation of the new LC compounds