Mechanism of chirality induction in photoresponsive chiral nematic liquid crystals

Abstract

We synthesized cyclic chiral compounds by linking a photoresponsive bisbenzothienylethene moiety with an axially chiral binaphthyl moiety. The N*-LCs, prepared by adding the chiral compounds as chiral dopants to N-LCs, exhibited a reversible chirality inversion by virtue of extremely high fatigue resistance in photo-isomerization between open and closed forms of the bisbenzothienylethene moiety. Moreover, the mechanism of chirality inversion in photoresponsive N*-LCs was examined by comparing helical twisting powers (HTPs) of the analogous compounds.