Photocontrolled chiral supramolecular assembly of azobenzene amphiphiles in aqueous media

Supramolecular molecular amphiphiles that are photoresponsive have been intensively developed for a wide range of smart functional materials. As a photoswitch that displays high chemical and thermal stabilities, the azobenzene motif has been intensively incorporated into distinct soft materials to control properties and provide high temporal and high spatial resolution. However, only limited examples of molecular azobenzene amphiphiles (AAs) with chiral character have been reported with complicated synthetic manifold and photochemical studies. Herein, we design a novel molecular AA, AA_Phe, with a simple molecular design and an L-amino acid motif. In addition to excellent photoresponsibility in organic media, AA_Phe exhibits a high capacity for supramolecular transformation in aqueous media, as well as supramolecular chirality controlled by noninvasive photostimulation, as found in encouraging photochemical studies. Investigations of supramolecular behavior show that the supramolecular chiral structure induced by AA_Phe assembles from microscopic to macroscopic length scales. The current design and studies of supramolecular assemblies of AA_Phe provide us with fundamental concepts for constructing macroscopic functional materials with supramolecular chirality.