Effect of lateral fluorine substitution far from the chiral center on mesomorphic behaviour of highly titled antiferroelectric (S) and (R) enantiomers

Abstract

Several new liquid crystalline chiral ester enantiomers in the (S) and (R) configuration were designed and characterised. In order to tune their mesomorphic properties, the molecular core was laterally substituted by fluorine atoms in different positions on the benzene ring placed in the molecular core far from the chiral centre. All the materials possess the self-assembling behaviour, specifically the paraelectric orthogonal smectic A*, the ferroelectric tilted smectic C* and antiferroelectric tilted smectic CA* phases over a broad temperature range down to room temperature. Properties of the materials were characterised by the polarising optical microscopy, differential scanning calorimetry, electro-optics and dielectric spectroscopy. Due to high chemical stability, reasonably broad temperature ranges of polar smectic mesophases (up to 110°C) and very high values of the optical tilt angle (40–45°) at saturation, these materials can be used as chiral dopants for the multicomponent orthoconic mixture design aimed for development of advanced electro-optic and photonic devices.