Structural and electronic properties of small platinum metallorganic complexes

A theoretical first-principles study of Ptn(ligand) m (n = 1–3) metallorganic complexes is performed, by varying the number of metal atoms and the nature and number of organic coordinate ligands (specifically, vinylic and arylic ligands). For each system, the nature of the bonding, the structure and the energetics of the metal/ organic-species interaction are analyzed to derive information on the growth of coated metal clusters in solution. It is found that two re´gimes can be distinguished: a ‘‘coordinatively saturated’’ re´gime, in which the ratio among the number of ligands and the number of metal atoms is high and a ligand/organic p-interaction mode is preferred, and a ‘‘coordinatively unsaturated’’ re´gime, in which the ligand/ metal ratio is low and a ligand/organic r-interaction mode is preferred. Reactive channels, such as oxidative insertion of Pt into C–H bonds with the corresponding formation of platinum hydride species, can be opened in the latter re´gime.