Highly tilted smectogens with bromine-substituted molecular core

Abstract

We have synthesised a series of rod-like mesogens with a bromine atom substituted laterally in the molecular core, which consists of four benzene rings, one biphenyl and two phenyl rings, connected by ester bridges. The terminal chiral chain contains a lactate unit. The physical properties of the compounds have been studied, and their SmA* and SmC* phases have been identified over a wide temperature range. The temperature dependency of the polarisation and tilt angle have been measured, together with the helical pitch and layer spacing, and dielectric spectroscopy has been carried out. On cooling, the tilt angle reaches a relatively high value, up to 45°.

Keywords:

• lactate unit
• dielectric properties
• orthoconic
• bromine substitution

Acknowledgments

This study was supported by projects IAA100100911 of the Grant Agency of ASCR and P204/11/0723 of the Czech Science Foundation. N.P. is grateful for support provided by grant SVV–2012–265303.