Synthesis and mesomorphic characterization of novel amphotropic steroidal esters

Abstract

Secondary metabolites are considered one of the inspirations for designing new materials. Steroids form a diverse category of secondary metabolites, the derivatives of which constitute a prominent class of soft materials exhibiting various self-assembled structures. This report attempts to illustrate the importance of the oligo-ethyleneoxy side chain on the liquid crystallinity of steroidal mesogens. The ethyleneoxy benzoates of sterols were found to show cholesteric and polymorphic smectic mesophases along with frustrated phases such as TGB and blue phase. The mesogenic tendency of these molecules was analyzed as a function of the length of the ethyleneoxy side chain as well as the steroidal moiety. Furthermore, these derivatives have been investigated for their amphotropic behavior. The analysis was carried out using POM, DSC, SAXS, and SEM techniques.