Platinum complexes vibrational studies

Hydride complexes of platinum have received considerable study since the preparation of PtHCl(PEt3)2- Spectroscopic studies by NMR techniques have been widely used because of the structural information which can be obtained from coupling constant data to Pt and other nuclei. Platinum is widely used as a heterogeneous catalyst, and vibrational studies on platinum hydride complexes have been useful for comparison of a hydrogen atom bonded to a single platinum with that bonded to a surface. Complexes of platinum have been used to catalyze hydrogenation, hydrosilylation and isomerization reactions with alkenes and alkynes, as well as H/D exchange reactions on alkanes. Hydride complexes are frequently proposed as intermediates in these reactions, and the pathways related to the known chemistry of hydride complexes. 

Kubelkova and coworkers studied the interaction of CO with platinum in a NaX zeolite [141]. They decomposed PtlNHj I]] on the zeolite under various conditions and observed distinct CO vibrational spectra for PtO-CO, Pt -CO, Pti -CO and [Pt(CO)2] complexes after CO adsorption at room temperature. Subsequent reduction with hydrogen resulted in characteristic particle size distributions with distinct CO vibrational frequencies depending on whether the clusters (-1.2 nm) were inside the supercages or outside the cages (-4.0nm). 

It has been suggested (162) that there exists only negligible 7r-backbonding in [AuCl(CO>], and a number of displacement reactions have been described (162, 163). Vibrational and NMR spectroscopic studies have been made of this complex (164), and the results have been compared with those for carbonyl complexes of palladium, platinum, rhodium, and iridium. 

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