STRUCTURE-PROPERTY RELATIONSHIPS IN LIQUID CRYSTALS: CAN MODELLING DO BETTER THAN EMPIRICISM?

This paper reviews the relationships observed experimentally between the physical properties of liquid crystals and the molecular structures of the constituent molecules, and reports molecular mechanics calculations designed to provide a predictive and interpretative basis for structure/property relationships in liquid crystals. The calculations are of the minimum energy configurations of dimers of interacting liquid crystal molecules, and the geometry of the dimers, relative orientation of molecular dipoles and the extent of parallel correlation are related to liquid crystal properties. A large number of structural types are examined and the results discussed in terms of dipole correlation, apolar angular correlation, chiral twist sense and transition temperatures of liquid crystals.