Hydroxo and Oxo Complexes of Platinum(II) Stabilized by Phosphanes: Synthesis and Characterization − X-ray Structures of cis-[L2Pt(μ-OH)]2(NO3)2 (L = PMe2Ph, PMePh2) and [{cis-(PMe2Ph)2Pt}3(μ-O)2]Cl2
Abstract
The dinuclear hydroxo complexes cis-[L2Pt(μ-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(μ-OH)]2X2 (L = PMe3, PMe2Ph; X = NO3−, ClO4−) with (NEt4)Cl·H2O or (AsPh4)Cl, in a 1:2 molar ratio, afforded a mixture of cis-[L2PtCl2] and [{cis-L2Pt}3(μ-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)2Pt}3(μ-O)2]Cl2 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)2PtCl2] as the only isolable species. The 31P 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)]. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2002)
