On the molecular theory of dimer liquid crystals

We present a statistical mechanics approximation scheme for the explicit treatment of spacer-mediated configurational correlations among the mesogenic units that form a dimer molecule. The approximation is applied to the description of the nematic phase of linear uniaxial dimers interacting via a standard molecular pair-potential. Transition temperatures, order parameters and pair correlation averages are calculated for different spacer lengths. The results readily reproduce the experimentally observed trends of phase transition thermodynamics and of dipolar correlations deduced from dielectric studies.