Organo-transition metal clusters: rational approaches to synthesis, structure, fluxionality, and reactivity

By using the isolobality principle, it is shown that the electronic structures of the 4- through 9-atom organo-transition metal clusters are closely analogous to the corresponding boranes. This parallelism is extended beyond simple structural similarities and is used to account for the high reactivity and nmr fluxionality of clusters which possess a vacant site on the polyhedral surface. Comparisons are also drawn with main group anionic and cationic clusters. Finally, it is shown that clusters containing gold atoms can, under certain circumstances, also follow the structural patterns of the boranes.