1,1' BIS(DIPHENYLPHOSPHINO)FERROCENE COMPLEXES OF PLATINUM(II) AND PLATINUM(I) - CRYSTAL AND MOLECULAR-STRUCTURE OF [(FE(ETA-5-C5H4PPH2)PT(MU-H)(MU-CO)PT(FE(ETA-5-C5H4PPH2)2)][BF4]-0.5H2O

A series of platinum(II) derivatives with 1,1′-bis(diphenylphosphino)ferrocene (L-L) were synthesized and characterized in solution mainly by 1H and 31P{1H} NMR spectroscopy. The series includes, besides the known Pt(L-L)Cl2 (1), the mononuclear species Pt(L-L)(pz)2 (2, pzH = pyrazole), Pt(L-L)(3,5-Me2pz) (3, 3,5-Me2pzH = 3,5-dimethylpyrazole), [Pt(L-L)(3,5-Me2pzH)2][BF4]2 (4), and [Pt(L-L)(H2O)2][BF4]2·xH 2O (5) as well as the dinuclear species [(L-L)Pt(μ-OH)2Pt(L-L)][BF4]2 (6) and [Pt2(L-L)2H3][BF4] (7). Reaction of the hydrido complex 7 with CO (room temperature, 1 atm) gave [(L-L)Pt(μ-H)(μ-CO)Pt(L-L)][BF4] (8), formally a platinum(I) derivative. The molecular structure of [(L-L)Pt(μ-H)(μ-CO)Pt(L-L)][BF4]·0.5H2O (8a) was determined by X-ray analysis: the complex crystallizes in the triclinic space group P1 with a = 12.411 (4) Å, b = 15.930 (5) Å, c = 16.922 (7) Å, α = 100.64 (3)°, β = 98.74 (3)°, γ = 104.34 (3)°, Z = 2, and V = 3166 (4) Å3. The structure was refined to a conventional R factor of 0.025. In the dinuclear cation, the platinum atoms have cis-square-planar coordination, which shows a significant distortion toward tetrahedral geometry with P-Pt-P angles of 103.68 (6) and 103.64 (6)°. The Pt-Pt distance is 2.790 Å.