Liquid Crystal Materials with Sulfur Atoms Incorporated in the Principal Structure. IV. New Liquid Crystal Compounds; 2-(p-Substituted phenyl)-5-alkyl-1,3-oxathianes

Abstract

Abstract 2-(p-Substituted phenyl)-5-alkyl-1,3-oxathianes, new liquid crystal compounds, were synthesized by the acetalformation reaction of the corresponding aldehydes and 2-alkyl-3-mercapto-1-propanols. The mesomorphic behaviors of these 1,3-oxathiane compounds were compared with those of the corresponding 1,3-dithianes and 1,3-dioxanes. Some of 2-(p-cyanophenyl)-5-alkyl-1,3-oxathianes exhibit monotropic nematic liquid crystal phase at room temperature, whereas 2-(p-alkoxyphenyl)-5-alkyl-1,3-oxathianes tend hardly to exhibit liquid-crystal phase. These mesomorphic characters seem to originate in the molecular width and bending at the 1,3-oxathiane ring.