Reversible dynamic full-color phototuning with a new chiral molecular switch containing linking group between chiral center and photosensitive group

Abstract

In this study, a new photoresponsive chiral molecular switch, where azobenzene was not directly connected to the axially chiral binaphthyl group, was successfully synthesized and used to induce helical superstructures in the achiral nematic liquid crystal (LC) host E7. Photoisomerization of the chiral molecular switch was carried out in both organic solvent and LC host upon light irradiation, contributing to the HTP difference at different photostationary states. The phototunable property of chiral molecular switch in E7 allowed dynamic, rapid and reversible tuning of the reflection color in cholesteric LC phase over the entire visible spectrum. The strategy breaks the restriction in common structures of photoresponsive chiral molecular switches, providing exciting insight into design for novel binaphthyl azobenzene derivatives with axial chirality.