A simple theory of molecular organization in fullerene containing liquid crystals

Abstract

Systematic efforts to synthesise fullerene containing LCs have produced a variety of successful model compounds. We present a simple molecular theory relating the self-organisation observed in these systems to their molecular structure. The interactions are modelled by dividing each molecule into a number of sub-molecular blocks to which specific interactions are assigned. Three types of blocks are introduced, corresponding to fullerene units, mesogenic units, and non-mesogenic linkage units. The blocks are constrained to move on a rectangular 3-dimensional lattice and molecular flexibility is allowed by retaining a number of representative conformations within the block representation of the molecule. Calculations are presented for a variety of molecular architectures including twin mesogenic branch mono-adducts of C60, twin dendro-mesogenic branch mono-adducts and conical (badminton shuttlecock) multi-adducts of C60. In spite of its many simplifications, the theory accounts remarkably well for the phase behaviour of these systems.