Synthesis of Homo- or Hetero-trinuclear Palladium(II)/Platinum(II) Compounds with Bridging Phosphido Ligands. Crystal and Electronic Structures (DFT) of [N(PPh₃)₂]₂[Pt₃(μ-PPh₂)₄(C₆F₅)₄] and of Its Oxidation Product [Pt₃(C₆F₅)₄(μ-PPh₂)₄]^†

The synthesis of the trinuclear phosphido complexes [NBu₄]₂[(C₆F₅)₂M(μ-PPh₂)₂M‘(μ-PPh₂)₂M‘ ‘(C₆F₅)₂] (M, M‘, M‘ ‘ = Pd(II), Pt(II), 1−5) is described. A study of the electrochemical behavior of these complexes is reported. The chemical oxidation of the homonuclear platinum derivative involving two electrons yields the complex [(C₆F₅)₂Pt(μ-PPh₂)₂Pt(μ-PPh₂)₂Pt(C₆F₅)₂] (6), which contains Pt in average formal oxidation state 2.67. The structure of the complexes has been established by spectroscopic means, and X-ray diffraction studies have been carried out on 1 and 6. Quantum chemical calculations at the B3LYP level of theory, using the LANL2DZ basis set, provide a satisfactory description of the structural, bonding, energetic, and electronic properties of these phosphido-bridged trinuclear M₃(II) compounds modeled as [(CF₃)₂M(μ-PH₂)₂M‘(μ-PH₂)₂M‘ ‘(CF₃)₂]^2- (M, M‘, M‘ ‘ = Pd(II), Pt(II), 1M−5M) and the oxidation product [Pt₃(μ-PH₂)₄(CF₃)₄] (6M).