Twin Ag10 Clusters Assembled into a Discrete Complex via Direction-Tuned Cooperative Coordination

The spatial organization of multiple atomically precise metal nanoclusters has emerged as a promising strategy to amplify and diversify their properties and to create functional supramolecular materials based on these materials. Here, we report the construction of a discrete complex encapsulating dimerized Ag10 clusters, whose structure in the crystalline state was observed by X-ray diffraction experiments. Such a self-assembly is achieved by modifying cooperative coordination approach that integrates acetylide protection and metal–pyridyl coordination, as confirmed through the stepwise X-ray observation of the related acetylide-protected monomeric Ag8 clsuter and its partial transformation via Ag–pyridyl capping. Photophysical measurements and quantum-chemical calculations demonstrated that the Ag10 dimer showed cluster-based photoluminescence mediated by electronic coupling between the silver cluster core and the carbazole moieties in the ligand framework, with quantum yields of 0.04 in CH2Cl2 solution and 0.10 in the solid state. This work thus suggests that the combination of discrete coordination self-assembly and acetylide-based cluster formation may indeed represent a new way to the oligomerization of large metal clusters to generate structurally precise assemblies.