Synthesis and mesomorphic properties of chiral smectic A phase liquid crystals of wide temperature range

Abstract

The synthesis of a novel chiral liquid crystal (LC) is described. Its structure and thermal phase behaviour have been characterised using ¹H nuclear magnetic resonance, mass spectroscopy, elemental analysis, differential scanning calorimetry, polarising optical microscopy and X-ray diffraction. The compound exhibited a chiral smectic A (SmA*) phase over a wide temperature range. Its electro-optical properties, including voltage–transmittance relationship, electroclinic effect and switching time have also been assessed, shedding light on the correlation between electro-optical properties and chemical structure. The potential of the SmA* compound for use in electro-optical applications that exploit the electroclinic effect is also discussed.

Keywords:

• liquid crystal
• chiral smectic A
• thermal phase behaviour
• electroclinic effect
• switching time

Acknowledgements

We should like to thank Dr Jey-Jau Lee for assistance with the XRD experiments at the National Synchrotron Radiation Research Centre (NSRRC) at beamline BL17A, Taiwan. Financial support for the project from the National Science Council of Taiwan, through 98–2221–E–011–004, is also gratefully acknowledged.