Supramolecular Assemblies of Donor-Acceptor Stenhouse Adduct Amphiphiles as Macroscopic Soft Scaffolds

Designing photo-harvesting and photoresponsive supramolecular systems in aqueous media, the fabrication of photoswitch as an amphiphilic structure enables non-invasive functional response by photoirradiation. Although most of aqueous supramolecular assemblies across multiple length-scale were driven by high-energy and bio-damaging UV-light, previously we reported donor-acceptor Stenhouse adduct (DASA) amphiphile controlled by while-light. Herein, we present a series of DASA amphiphiles with minor structural modifications on the chain length of alkyl-linker, which connect DASA motif with hydrophilic part. The excellent photoswitchabilities in organic media and photoresponsiveness in aqueous media, driven by visible-light, are revealed with UV-vis absorption spectroscopy. The supramolecular structures are confirmed by electronic microscopies across multiple length-scale, while the supramolecular packing structures at macroscopic length-scale are revealed with X-ray diffraction. Driven by visible-light irradiation, the large geometrical transformations of DASA amphiphiles enable supramolecular transformation at microscopic length-scale, and subsequently disassemble the macroscopic soft scaffolds of DASA amphiphiles. The results indicate the feasibility in developing visible-light controlled macroscopic scaffolds for offering opportunity in fabricating biomedical materials with visible-light controlled microenvironment and future soft robotic systems.