Derivative Chemistry of Ag29 Nanoclusters

Metal nanoclusters represent a unique class of nanomaterials with monodisperse sizes, atomically precise structures, and rich physicochemical properties, and they find wide applications in optics, catalysis, and biomedicine. The strong quantum size effects and discrete electronic energy levels endow metal nanoclusters with structure-dependent properties, where any perturbation of their compositions or structures induces significant variations in their properties. This makes the research of metal nanoclusters particularly exciting but also challenging, as small changes in their atomic composition or arrangement can result in substantial differences in their behavior. As a result, the study of metal nanoclusters follows a node-style research pattern, wherein major breakthroughs often lead to new insights into their structural and functional properties. However, despite these advances, the systematic exploration of these materials remains highly challenging. In recent years, there has been increasing interest in the development of unified theoretical models that can predict and control the properties of metal nanoclusters, potentially making them ideal candidates for programmable nanomaterials. Key examples of well-studied nanoclusters include Au₂₅(SR)₁₈ and Ag₄₄(SR)₃₀, which have provided valuable insights into the fundamental principles of metal nanocluster chemistry. Nevertheless, given the vast differences observed among various cluster frameworks, there is an urgent need to develop new models and explore versatile approaches for the preparation of nanoclusters with tunable functionalities. In this regard, our research group has focused on advancing the derivative chemistry of Ag₂₉-templated nanoclusters.

In this Account, we emphasize our progress in investigating the derivative chemistry of Ag₂₉ nanoclusters, focusing on several key areas, such as their controlled preparation, structural determination, molecular-level structural regulation, supramolecular ordered assembly, and the exploration of structure–property relationships. Initially, we provide a comprehensive overview of the structural manipulation of Ag₂₉ nanoclusters on the molecular scale, highlighting various molecular operations that enable precise control over their properties. These operations include kernel alloying, ligand engineering, and counterion regulation, which serve as fundamental strategies for tuning the composition and structure of these nanoclusters. Tens of Ag₂₉ cluster derivatives with comparable compositions and constructions are presented, and the corresponding structure–property correlations are disclosed as well. Then, we summarize the research progress regarding Ag₂₉ clusters at the supramolecular level, which involves the self-assembly of Ag₂₉ nanoclusters into supracrystalline aggregates or host–guest assemblies in both crystalline and solution states. The hierarchical complexity and ordered nature of these supramolecular aggregates offer promising new opportunities for designing advanced nanomaterials with enhanced functionality, such as improved catalytic, optical, and electronic properties. Finally, we highlight the major challenges and future directions for the derivative chemistry of Ag₂₉ nanoclusters, particularly in the realms of molecular and supramolecular chemistry. We believe that the continued development of Ag₂₉ cluster derivatives will provide valuable insights and guide the synthesis of novel nanoclusters or cluster-based nanomaterials with customized structures and unique properties, addressing the growing demand for cluster materials in various high-impact applications.