MULTIPLE CONTRIBUTIONS TO POTENTIALS OF MEAN TORQUE FOR SOLUTES DISSOLVED IN LIQUID-CRYSTAL SOLVENTS - A COMPARISON OF THE ORIENTATIONAL ORDERING OF ANTHRACENE AND ANTHRAQUINONE AS SOLUTES IN NEMATIC SOLVENTS

The two principal orientational order parameters of anthracene and anthraquinone as solutes in several liquid crystal solvents have been obtained via deuterium NMR spectra. The ordering of anthraquinone is much more solvent dependent than that of anthracene, and possible explanations of this behaviour are examined. In particular, the possibility that electrostatic as well as dispersive and repulsion forces could contribute to a mean field potential is explored. It is concluded that the most probable cause of the large differences in orientational ordering of these two molecules in some solvents, but not in others, is a dependence on both solute and solvent of order parameters CBAR-4,0+ and CBAR-2,0+ for the distribution of solute-solvent intermolecular vectors.