Cluster Compounds: Inorganometallic Compounds Containing Transition Metal & Main Group Elements

Abstract

Abstract The relationships between p‐block element cages and d‐block element clusters, as evidenced by the structures and properties of mixed main group–transition metal compounds, are explored. After a review of the cluster‐bonding characteristics of main group and transition metal homonuclear clusters, including the role of hydrogen atoms and internal or external ‘ligand’ fragments, the related but more complex behavior of main group–transition metal clusters is illustrated. The emphasis is on how the competition between the fundamental bonding properties of p‐block and d‐block elements is expressed in geometric and electronic structure as well as reactivity. Thus, for a limited number of cluster shapes, examples of known compounds are compiled, thereby illustrating the convenience of the cluster versus metal–ligand view as well as outlining the numerous compounds yet to be synthesized and evaluated. Finally, the reactivity of these ‘inorganometallic’ clusters is illustrated. Not only are examples analogous to those found in the homonuclear systems given but so also are examples of unexpected reactivity generated by the synergistic main group–transition metal network.