Photoinduced silver(I) cluster transformation for in-situ construction of heterogeneous core–shell crystals

Heterogeneous crystalline materials have recently attracted much attention, but their development is limited by the difficulty of efficient preparation, particularly solid-phase preparation. Here, a photosensitive silver(I) cluster crystal, Ag₉(S^tBu)₆(Hdpa)₆·(PF₆)₃ (Ag₉-Y), was obtained, which could change from colourless to red, accompanied by a change in photoluminescence (yellow to red) under ultraviolet irradiation. Further studies reveal that the intriguing transformation occurs due to the partial intercluster conversion (from Ag₉ to Ag₆₂) on the surface of the Ag₉ crystal, resulting in the formation of heterogeneous core–shell crystals (Ag₉-YR). Surprisingly, although this transformation causes a significant change in the photophysical properties, the host lattice does not change, and a multilayer heterogeneous crystal is successfully constructed (Ag₉-YRY) by combination with the epitaxial growth method. This strategy of utilizing partial photosensitive cluster conversion to achieve differences in crystal zoning properties provides a new approach for constructing multifunctional heterogeneous crystalline materials with broad application prospects.