High Figure-of-Merit Laterally Fluorinated Biphenyltolane-Isothiocyanates

Abstract

We have designed, synthesized, and evaluated the physical properties of some high birefringence (Δn) isothiocyanato biphenyl-tolane liquid crystals. These compounds exhibit Δn ∼ 0.48–0.52 at room temperature and wavelength λ = 633 nm. Laterally substituted short alkyl chains and fluorine atom eliminate smectic phase and lower the melting temperature. The moderate melting temperature and very high clearing temperature make those compounds attractive for eutectic mixture formulation. A eutectic mixture based on those compounds was formulated and its physical properties evaluated.

Keywords:

• eutectic mixtures
• high birefringence
• isothiocyanato bistolanes
• liquid crystals

Acknowledgments

This work is supported by DARPA Bio-Optics Synthetic Systems program under Contract No. W911NF04C0048, and NATO Programme Security Through Science, Collaborative Linkage Grant No. CBP.EAP.CLG 981323.