A non-mesogen, consisting of two stilbazole moieties as proton accepting end groups linked by a triethylene glycol unit, was synthesized. Monotropic smectic B phases were observed for mixtures with nonanoic acid up to tetradecanoic acid as proton donors. Enantiotropic nematic and, in some cases, monotropic smectic A phases were observed with 4-methyl-, 4-methoxy- and 4-halo-benzoic acids as proton donors. The stability of the induced mesophases decreased with 3- and 2-substituted benzoic acids. No mesophase was observed with aliphatic dicarboxylic acids as donors. The results are explained on the basis of the nature and molecular interactions involving the constituent molecules. Nematic phases were obtained by mixing 4-methoxy-4′-stilbazole with structural isomers of methyl-, methoxy-, and halo-benzoic acid derivatives, all the components are rod-like nonmesogens. It was shown by NMR, IR, uv-vis and fluorescent spectroscopic studies that the hydrogen bonds played the central role. Enantiotropic with wide temperature ranges were observed for the mixtures of 4-substituted benzoic acids. The stability of induced mesophase decreased for the mixtures of 3- and 2-substitutions.
