Enhancement of thermal, dielectric and electro-optical properties of fluoro hydrogen-bonded liquid crystals.

The present work reported the synthesis and the characterisation of laterally fluorinated handed bond liquid crystals (HBLCs) prepared by intermolecular hydrogen bonds between 4-pentyl-4-biphenylcarbonitrile (5CB) and 4-(nonyloxy)-3-fluoro benzoic acid (9OBAF). This compound-denoted 9OBAF-5CB was characterised by Fourier transform infrared spectroscopy (FTIR) and their mesomorphic properties were studied by polarising optical microscope (POM) and differential scanning calorimetry (DSC). Moreover, this compound shows a wide nematic phase with relatively high birefringence ( Δ n = 0.24 , modest dielectric anisotropy Δ ε = 5 , low viscosity (γ = 182.9 mPas). The enhancement of these parameters compared to that in individual compounds (9OBAF) and 5CB was obtained and discussed. [ABSTRACT FROM AUTHOR]