Reactions of tris(triphenylphosphine)platinum(O). I. Preparation and properties of bis(triphenylphosphine)platinum(O)-silicon tetrafluoride

Abstract

Treatment of tris(triphenylphosphine)platinum(0) with silicon tetrafluoride affords the Lewis salt bis(triphenylphosphine)platinum(0)-silicon tetrafluoride, [(CeHshPLPt'SiFj (I). The reactions of compound I with I2, HC1, and NH3 are discussed. The pyrolysis of I is compared to that of .[(CeHslsPJsPt with both complexes affording benzene and a nonvolatile platinum species which exhibits an esr signal, g = 2.014. A new SiF5~salt, triphenylmethylphosphonium pentafluorosilicate, has been prepared and the chemistry of SiF5_ salts is discussed and compared to that of I.

Synthetic, Structural, Spectroscopic, and Theoretical Studies of Structural Isomers of the Cluster Pt3(μ-PPh2)3Ph(PPh3)2. A Unique Example of Core Isomerism in Phosphine Phosphido-Rich Clusters

“…The nature of the ubiquitous “red platinum clusters” variously generated by pyrolysis or fragmentation of zerovalent platinum complexes such as Pt(PPh 3 ) 4 is not yet fully understood. These 14a,− and related , reactions proceed by cleavage of phosphorus−carbon bonds and formation of μ-PPh 2 and often of Pt−phenyl linkages. Such cleavage reactions induced by transition metals have received considerable attention because of their potential role in the deactivation of phosphine-containing homogeneous catalysts. 1c, One would anticipate that the number and the nature of the products formed will depend on the phosphine ligand, the phosphine to metal ratio, and the experimental conditions.…”

Lewis base properties of platinum(0) complexes. III. Adducts between platinum and titanium tetrachloride

“…Evidence has been obtained for the dissociation of TiCU from I when dissolved in o-dichlorobenzene, eq 2. The fact that this equilibrium favors I at room (T1C14)sPt[TiCl4-P(C6Hs)3]3 * (TiCl4)2 .xPt[TiCl4-P(C6H5)3]3 + xTiCl4 (2) temperature was verified by the observation that when a solution of I was maintained, in vacuo, for 14 hr at 25°, it remained dark green and very opaque. Furthermore, the infrared spectrum of the volatiles, in equilibrium above the solution, indicated only the solvent and no gaseous TiCU.…”

“…A variety of reaction conditions have been employed in studying this system and a summary of the pertinent data from six reactions is presented in Table I. The measured weight gain of the contents of the reaction apparatus can be directly related to the amount of TiCL that has been coordinated to the starting platinum compound because (1) only TiCL is added to [(CóHsLPlsPt, (2) unreacted TiCL is the only volatile material detected at the conclusion of the reaction, (3) PfCeHsL is not permanently displaced, (4) neither TiCL-P(C6H5)3 nor TiCL-lPfCóHsL is a reaction by-product, and (5) I represents a single material based on its microcrystalline homogeneous appearance. Based 0 Initial TiCl, employed; determined by estimation of the volume of TiCl4 present.…”

Trans addition of halogens to tetrakis(triphenylphosphine)platinum(0)

“…Most spectral properties (uv, ir, pmr, mass spectral) of 1 and 2 are identical or nearly so, but the nature of the isomerism of 1 and 2 is established by their rotations of similar magnitude but opposite sign (Table 1), by the nearly mirror image relationship of their CD curves,6 and by the conversion of both 1 and 2 to streptoval C [3, C40H49NO]4,3 mp 140-143°, [e]24D -92.3°( c 0.013, CHC13)] on treatment with sodium metaperiodate.7 Significantly, while most cmr chemical shifts for 1 and 2 are nearly identical,83 those for C-15 and C-16, which lie above the acetate group in 1 but below the acetate group in 2, differ considerably (C-15 at 153.9 ppm from TMS for 1, 149. 3 Journal of the American Chemical Society / 97:1 / January…”