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]

Abstract

The synthesis of the trinuclear phosphido complexes [NBu 4 ] 2 [(C 6 F 5 ) 2 M(µ-PPh 2 ) 2 M′(µ-PPh 2 ) 2 M′′(C 6 F 5 ) 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 [(C 6 F 5 ) 2 Pt(µ-PPh 2 ) 2 Pt(µ-PPh 2 ) 2 Pt(C 6 F 5 ) 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 M 3 (II) compounds modeled as [(CF 3 ) 2 M(µ-PH 2 ) 2 M′(µ-PH 2 ) 2 M′′(CF 3 ) 2 ] 2-(M, M′, M′′ ) Pd(II), Pt(II), 1M-5M) and the oxidation product [Pt 3 (µ-PH 2 ) 4 (CF 3 ) 4 ] (6M).a The symmetry transformation used to generate equivalent P(2′) atom is -x, -y, -z.

Synthesis and Reactivity of the Unsaturated Trinuclear Phosphanido Complex [(C6F5)2Pt(μ-PPh2)2Pt(μ-PPh2)2Pt(PPh3)]

“…The geometry around Pt (3) is identical with that found for phosphanidoplatinum(I) complexes bonded to terminal phosphanes (or phosphinites) and bridged by diorganophosphanides of the general formula [(PR 1 2 R 2 )Pt(μ-PR 3 2 ) 2 Pt(PR 4 2 R 5 )](Pt−Pt) (R 1 = R 2 = R 4 = R 5 = Me, R 3 = t Bu; R 1 = R 2 = R 4 = R 5 = Ph, R 3 = t Bu; 34 R 1 = R 4 = Me, R 2 = R 5 = OMe, R 3 = cyclo-C 6 H 11 ; 5 R 1 = R 2 = R 3 = R 4 = R 5 = Ph). 35 Considering that the geometry of Pt(2) is reminiscent of that of the known phosphanido-bridged Pt III atoms, i.e., Pt 1/2 in [(C 6 F 5 ) 2 Pt 1 (μ-PPh 2 ) 2 Pt 2 (C 6 F 5 ) 2 ](Pt−Pt), 10 [(C 6 F 5 ) 2 Pt 1 (μ-PPh 2 ) 2 Pt 2 (μ-PPh 2 ) 2 Pt 3 (O,O-acac)](Pt 1 −Pt 2 ) + , 31 and [(C 6 F 5 ) 2 Pt 1 (μ-PPh 2 ) 2 Pt 2 (μ-PPh 2 ) 2 Pt 3 (C 6 F 5 ) 2 ](Pt 1 −Pt 2 ), 36 On the other hand, the Pt 2 and Pt 3 signals of 1 (δ −4720 and −5228, respectively) were obtained by recording a 1 H− 195 Pt HMQC NMR spectrum (Figure 3), which was set to exploit the scalar coupling between the o-H of the phenyl rings and Pt atoms. Once the chemical shifts of each of the three 195 Pt signals were located, their fine structures were obtained by recording a 1D 195 Pt{ 1 H} NMR spectrum ( Figure S1 in the Supporting Information), which showed inter alia a coupling constant between Pt 2 and Pt 3 of 515 Hz.…”

An organometallic tetranuclear cluster with phosphine and phosphido ligands in nonclassical bonding modes: X-ray structural characterization

“…Crystal data and other details of the structure analysis are presented in Table 1. Complex 1 is a tetranuclear cluster in which the ''(C 6 F 5 ) 2 Pt(1)(l-PPh 2 ) 2 Pd(1)'' fragment shows the usual arrangement with the diphenylphosphido ligands bridging the metal centres [1,2,[4][5][6][7]. The core of this fragment is almost planar and the Pt(1)-Pd(1) distance is 2.745(1) Å .…”

Dinuclear and Trinuclear Ni−, Pd−, and Pt−Halide Complexes of the Easily Accessible Chiral Ligand P,P,P-Tris[(+)-9-phenyldeltacyclan-8-yl]-1,2-bis(phosphanyl)benzene

“…[11] In 2001 a series of new trinuclear complexes was described, which in contrast to our compounds (two phosphido and two halide bridges) contained four diphenylphosphido bridges. [12] An X-ray structural analysis of one of the trinuclear complexes showed a chair configuration with regard to the three-square array. The roof angles between the squares were 152.7°in agreement with our results.…”