Hydroxo and oxo complexes of platinum(II) stabilized by phosphanes: Synthesis and characterization - X-ray structures of cis-[L2Pt(mu-OH)](2)(NO3)(2) (L = PMe2Ph, PMePh2) and [{cis-(PMe2Ph)(2)Pt}(3)(mu-O)(2)]Cl-2

The dinuclear hydroxo complexes cis- [L2Pt(mu-OH)](2)(NO3)(2) (L = PMe2Ph and PMePh2) have been characterized by single-crystal X-ray analysis, and their reactivity towards chloride ions has been investigated. Reaction of cis-[L2Pt(mu-OH)](2)X-2 (L = PMe3, PMe2Ph; X = NO3-, CIO4-) with (NEt4)CI.H2O or (AsPh4)CI, in a 1:2 molar ratio, afforded a mixture of cis-[L2PtCl2] and [{cis-L(2)pt}(3)(mu-O)(2)](2+) in ca. equimolar amounts. The trinuclear oxo compounds, separated by fractional crystallization of the reaction mixtures, were fully characterized by spectroscopic techniques, and the derivative [(cis-(PMe2Ph)(2)Pt)(3)(mu-O)(2)]CI2 was also characterized by X-ray diffraction methods. Under the same experimental conditions, the structurally analogous hydroxo complex, stabilized by the less basic and more hindered PMePh2 ligand, reacted with Cl- to give cis-[(PMePh2)(2)PtCl2] as the only isolable species. The P-31 NMR spectroscopic analysis of the reaction mixtures allowed the detection of a moderately stable product, which is most likely to be the neutral hydroxo complex cis-[L2PtCl(OH)].