Mesomorphic properties of troponoid esters and amides with cholest‐5‐ene‐3β‐carboxylic acid moiety

Abstract

Troponoid esters and amides connected with cholest‐5‐ene‐3β‐carboxylic acid have been synthesized to characterize their mesomorphic properties and to compare them with those of the corresponding benzenoids. 5‐Alkoxytroponyl esters and amides with a long alkoxy group exhibited a twist grain boundary A* phase, as well as chiral nematic and smectic A* (SmA*) phases. The corresponding benzenoid esters exhibit SmA* and blue phases and the benzenoid amides only a SmA* phase. The differences between the mesomorphic properties are discussed in terms of the structural features of the core.