A newly fascinating approach to construct pillar[5]arene functionalized ester derivatives for nematic liquid crystalline behavior

Abstract

A Pillar[5]arene linked 4-n-alkoxy benzoic acid based multifunctional supramolecular systems ((PB1-PB4) with variable alkyl chains were synthesized and well characterized. The microscopic and thermal behaviors of the compounds were investigated by using POM, DSC, and TGA analysis. All four pillar[5]arene-ester based macrocyclic compounds display nematic type mesomorphic properties, with a well-known schlieren and droplets type texture pattern observed in all four ten-side substituted pillarene derivatives. All four materials exhibit enantiotropic mesogenic behavior with a wide temperature range and thermal stability. The material with higher alkyl chain exhibit nematic phase at lower temperatures compared to materials with lower alkyl chain substitutions. Furthermore, we have investigated the structure property relationship to understand the influence of substitution on the rigid core of pillar[5]arene and its ability to induce different types of liquid crystalline behaviors.