Af. Terzis et al., SHAPE-DOMINATED ORDERING IN NEMATIC SOLVENTS - A DEUTERIUM NMR-STUDY OF CYCLOALKANE SOLUTES, Journal of the American Chemical Society, 118(9), 1996, pp. 2226-2234
We examine a series of closely related, relatively inert, cyclic aliph
atic solutes-cyclohexane, methylcyclohexane, 1,1-dimethylcyclohexane,
1,4-trans-dimethylcyclohexane, 1,4-cis-dimethylcyclohexane, trans-deca
lin, and cis-decalin-in a nematic solvent and demonstrate that their o
rientational ordering can be accurately described in terms of purely h
ard-body interactions with the solvent molecules. These interactions a
re treated explicitly in the context of a statistical mechanical appro
ximation wherein the orientational correlations among the solvent mole
cules are not taken into account directly. We test the theory by predi
cting the observed order parameters of the aliphatic solutes as determ
ined with deuterium nuclear magnetic resonance. The utility and limita
tions of a description of solute ordering derived exclusively from har
d-body interactions is discussed.