Light-Driven Chiral Switching of Supramolecular Metallacycles with Photoreversibility

The construction of artificial chiral self-assembled systems has evolved to be one of the most attractive topics within supramolecular chemistry and materials science. However, stimuli-responsive chirality transcription with enantiospecific photoreversibility still remains challenging for chiral metallasupramolecular structures because of the lack of appropriate building blocks. Herein, we present a chiral photoresponsive family of diarylethene-containing dipyridyl donors and their coordination-driven self-assembly behavior with the 120° di-platinum(II) acceptor. The photochromic trimer units in the assembled metallacycles exhibit an unprecedented concerted photoconversion process without a step-by-step transformation. By taking advantage of the full-separated photoactive dipyridyl donor enantiomers based on the sterically hindered system, we have successfully achieved the phototriggered chirality transformation in supramolecular multi-dithienylethene metallacycles arising from axial helicity and central asymmetry, thereby establishing light-driven control in circular dichroism. Such unique photoreversible self-assembled metallacycles with photoinduced enantiospecificity enable the potential chemical platform for bistable chiroptical switching and non-destructive information encoding.