AN ORIENTATIONAL STUDY OF SMALL SOLUTES IN ZERO ELECTRIC-FIELD GRADIENT NEMATIC LIQUID-CRYSTAL MIXTURES

The solutes m-dichlorobenzene, o-dichlorobenzene. p-dichlorobenzene, o -dicyanzene, furan, tetrathiofulvalene, and fluorobenzene are studied in the zero electric field gradient mixtures 56.5 wt % 1132/EBBA and 7 0 wt % 5CB/EBBA using proton NMR. The two second-rank-order parameters obtained for each solute from analysis of the NMR spectra indicate th at the solutes experience a similar anisotropic potential in both mixt ures. The results are interpreted in terms of two models for the short -range anisotropic potential experienced by the solutes.