Liquid crystalline materials: physical properties and intermolecular interactions

Abstract

The physical properties and the phase behaviour of some nematic liquid crystals are discussed, with emphasis on the influence of short-range antiparallel dipole correlation that occurs in mesogenic compounds with a strong terminal dipole moment. Evidence for this effect, which stems especially from dielectric studies, is summarized. Variations of the dipole correlation with molecular structure can explain the sometimes unexpected phase behaviour and physical properties of these substances. A qualitative model is given in terms of a monomer-dimer equilibrium.