Photoresponsive chiral molecular crystal for light-directing nanostructures

A photoresponsive chiral molecular crystal (abbreviated as PCMC) was programmed and synthesizied by localizing a chiral isosorbide at the core between two amphiphilic azobenzene building blocks. Owing to the bent-shaped geometry, the PCMC can self-organize into helical nanoribbons with a highly ordered smectic domain. Since the PCMC has not only an intrinsic molecular chirality but also a photoresponsive molecular function, the helical nanoribbons with single handedness were transformed to flat nanobelts by irradiation with ultraviolet light. Additionally, its chiroptical properties were fully recovered to the initial state upon exposure to visible light. Fine tuning the nanoarchitectures using the remote controllable feature of the PCMC presented in this work can lead the design of novel functional materials that are potentially applicable as optical sensors and biomimetic devices.