Super High Birefringence Isothiocyanato Biphenyl-Bistolane Liquid Crystals

We have designed, synthesized, and evaluated the physical properties of some high birefringence (Δ n ) isothiocyanato biphenyl-bistolane liquid crystals. These compounds exhibit Δ n ∼0.7–0.8 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. The simulated absorption spectra agree reasonably well with the measured results.