Polynuclear organometallic clusters: synthesis, structure, and reactivity studies
Polynuclear organometallic clusters featured by the aggregation of several metal ions and the involvement of carbon-metal bonds are considered to be possible intermediates in many metal catalytic reactions. The studies on their structures and reactivity are significant for understanding the nature of carbon-polymetallic bonds, and meanwhile crucial to elucidate catalytic mechanisms of many catalytic reactions, especially with metal clusters and metal nanoparticles as homogeneous or heterogeneous catalysts. This feature article highlights the evolution of the controllable synthesis of C(sp)-centered polynuclear silver or copper clusters within neutral polydentate macrocyclic ligands in light of the coordination-based cooperative effect, and the acquisition of C(sp2)-centered geminal multinuclear silver or gold clusters via multi-metallic activation and transformation of primitive metal clusters. The studies spotlight the unique bonding between polymetallic and organic species and the uncommon stabilizing effect in the acquired polymetalated organometallics, and additionally provide a structural model for in-depth understanding detailed catalytic processes of metal clusters and heterogeneous catalysts in organic transformations.