Liquid Crystalline Cholesteryl Azo Dyes

Abstract

Abstract Compounds of the formula 3(β)-cholestery where X=O or NH, Ar=1,4-phenylene or 3-hydroxy-1,4-phenylene, and Ar'=phenyl, 4′-cyanophenyl, 4′-nitrophenyl, or 4′-N,N-diethylaminophenyl were prepared which have broad liquid crystalline ranges as determined by differential scanning calorimetry. Changes were found in the characteristics of the parent azobenzene compounds following carbonate or carbamate formation. The pitch and order parameters of the title compounds were determined in several nematic hosts. In addition, a method for assessing the alignment of the cholesteryl moiety in liquid crystalline hosts is presented.