DINUCLEAR HYDROXO COMPLEXES OF PLATINUM(II) WITH GROUP-V CHELATING LIGANDS - CRYSTAL AND MOLECULAR-STRUCTURE OF [(DPP)PT(MU-OH)2PT(DPP)][BF4]2.1/2 CH3OH (DPP = 1,3-BIS(DIPHENYLPHOSPHINO)PROPANE

The synthesis of a series of dinuclear hydroxo platinum(II) derivatives [(L-L)Pt(mu-OH)2Pt(L-L)][BF4]2, 1-6 [L-L:Ph2PCH2PPh2(dpm), 1; Ph2P(CH2)2PPh2 (dpe), 2; Ph2P(CH2)3PPh2 (dpp), 3; Ph2P(CH2)4-PPh2 (dpb), 4; Ph2P(CH2)2AsPh2 (dpase), 5; Ph2As(CH2)2AsPh2 (dase), 6) has been accomplished by reaction of the mononuclear chlorides Pt(L-L)Cl2 with two equivalents of AgBF4 in methanol solution. The species 1-6 were characterized by FAB-MS, IR and NMR (H-1, P-31{H-1}, and Pt-195{H-1}) spectroscopic techniques: in all cases, complex 1 included, L-L acts as a chelating ligand. The spectroscopic data show that the dimeric unit is maintained in the vapour phase (FAB/MS), in solution (P-31{H-1}), and in the solid state (X-ray). The structure of complex 3 has been determined by single-crystal X-ray diffraction: monoclinic, space group P2(1)/c with a = 23.339(3), b = 14.204(2), c = 17.874(3) angstrom, beta = 110.1 7(2)-degrees, R = 0.043 and R(w) = 0.056 for 5554 observed reflections having I>3sigma(I). Aspects of the reactivity of the hydroxo species with HBF4 under various conditions are discussed.