COMPLEXES WITH A TRIFLUOROPHOSPHINE LIGAND BRIDGING A TRIPALLADIUM TRIANGLE - STRUCTURE OF ))(MU(3)-I)(MU-BIS(DIPHENYLPHOSPHINO)METHANE)(3)]I

synthetic and structural work describe the first examples of bridging monophosphine ligands. Treatment of Pd2(mu-dpm)2X2 (1; dpm is bis(diph enylphosphino)methane; X is Cl or I) with excess trifluorophosphine yi elds brown [Pd3(mu3-PF3)(mu-X)(mu-dpm)3]X and yellow Pd(dpm)X2. Metath esis of [Pd3(mu3-PF3)(mu-Cl)(mu-dpm)3]cl with sodium iodide yields red -brown [Pd3(mu3-PF3)(mu3-I)(mu-dpm)3]I. [Pd3(mu3-PF3)(mu3-I)(mu-dpm)3] I.3CH2Cl2 crystallizes in the monoclinic space group Pn with a = 11.14 9(2) angstrom, b = 15.635(3) angstrom, c = 22.857(5) angstrom, and bet a = 90.17(2)-degrees at 130 K with Z = 2. Refinement of 8454 reflectio ns with (F > 4.sigma(F)) and 500 parameters yielded R = 0.063 and R(w) =0.071. The structure of the cation consists of a nearly equilateral triangle of palladium atoms bridged at the edges by dpm ligands and ca pped by the triply bridging phosphorus atom of the trinuorophosphine, An iodide ligand is almost symmetrically situated n the opposite face. Studies of the Pd2(mu-dpm)2Cl2/PF3 reaction by variable-temperature ( P{H})-P-31-H-1 NMR spectroscopy show that a variety of species are for med in the complex reaction that leads to the eventual formation of [P d3(mu-PF3)(mu-Cl)(mu-dpm)3]Cl.