Metal Exchange in Organometallic Cluster Compounds

Abstract
In organometallic clusters with three, four, five, and six metal atoms metal-ligand fragments can be replaced by isolobal units. Fe(CO)3 and Co(CO)3 are good leaving groups. Organometallic units of the chromium, manganese, iron, cobalt, and nickel subgroups have been incorporated. The yields of the reactions can be remarkably high considering that during the replacement at least three bonds have to be broken and reformed. One-step and two-step reactions can be employed. Mechanistically, three reaction pathways have to be considered: fragmentation-reconstitution, elimination-addition, and addition-elimination. The new clusters obtained open up hitherto inaccessible aspects of cluster chemistry.