13965-02-1Relevant articles and documents
Reactions of tBu2P-PLi-PtBu2 with [(Et3P)2MCl2] (M = Ni, Pd, Pt). Synthesis and properties of [(1,2-η-tBu2P=P-PtBu 2)M(PEt3)Cl] (M=Ni, Pd)
Baum, Elke,Matern, Eberhard,Robaszkiewicz, Andrzej,Pikies, Jerzy
, p. 1073 - 1077 (2006)
tBu2P-PLi-PtBu2·2THF reacts with [cis-(Et3P)2MCl2] (M = Ni, Pd) yielding [(1,2-η-tBu2P=P-PtBu 2)Ni(PEt3)Cl] and [(1,2-η-tBu 2P=P-PtBu2)Pd(PEt3)Cl], respectively. tBu2P-PLi-tPBu2 undergoes an oxidation process and the tBu2P-P-PtBu 2 ligand adopts in the products the structure of a side-on bonded 1,1-di-tert-butyl-2-(di-tert-butylphosphino)diphosphenium cation with a short P-P bond. Surprisingly, the reaction of tBu2P-PLi-P tBu2·2THF with [cis-(Et3P) 2PtCl2] does not yield [(1,2-η-tBu 2P=P-PtBu2)Pt(PEt3)Cl].
Equilibria of the thiametallacycles with tris(triethylphosphine)platinum(0) and dibenzothiophene, benzothiophene, or thiophene: The hydrodesulfurization reaction
Garcia, Juventino J.,Mann, Brian E.,Adams, Harry,Bailey, Neil A.,Maitlis, Peter M.
, p. 2179 - 2186 (1995)
The thiaplatinacycles, [(PtSC12H8)(PEt3)2], 1, [(PtSC8H6)(PEt3)2], 2, and [(PtSC4H4)(PEt3)2], 3, in which Pt(PEt3)2 has inserted into one C-S bond of dibenzothiophene (DBT), benzothiophene (BT), and thiophene (T), respectively, are formed by the reversible reaction of tris(triethylphosphine)platinum(0) with the thiophene. The structure of complex [(PtSC8H6)(PEt3)2] (2) was confirmed by an X-ray determination that showed a square-planar Pt(II) bound to two cis PEt3 ligands, and to the S and the CH=, in a six-membered Pt-S-C-C-C-C ring [Pt-S(1), 2.315(5) ?; Pt-C(4), 2.035(19) ?; Pt-P(1), 2.301(5) ?, trans to S(1); and Pt-P(2), 2.386(5) ?, trans to C(4); P(1)-Pt-P(2), 97.6(2)°; S(1)-Pt-P(2), 87.0(2)°; S(1)-Pt-C(4), 88.6(6)°; P(1)-Pt-C(4), 86.8(6)°]. The adducts 1 and 3, derived from DBT and T, have been shown to have similar structures spectroscopically. The free thiophenes and Pt(PEt3)3 are regenerated on heating complexes 1-3 with Et3P; [(PtSCaHb)(PEt3)2] + Et3P ? [Pt(Et3P)3] + SCaHb. Keqm = [Pt(Et3P)3][SCaHb]/[PtSCaH b)(PEt3)2][Et3P] and is 10 for 1 (DBT) and 3 (T) and 1 for 2 (BT) at 100 °C. The complexes 1-3 undergo a variety of cleavage reactions; thus, the Pt-C bond in 1 is cleaved by HCl to give 2-phenylthiophenol and [Pt(PEt3)2Cl2], and all three complexes are degraded by hydride reagents to give the completely desulfurized hydrocarbons: biphenyl from 1, styrene and ethylbenzene from 2, and butadiene and butenes from 3. When the reactions are carried out with Et3SiH as reducer, the complex [Pt(SH)(H)(PEt3)2] is identified among the products, together with [Pt(Et3Si)(H)(PEt3)2], The former is a coproduct of the desulfurization, while the latter arises from addition of Et3SiH to [Pt(PEt3)2] (from reversal of the formation of [(PtSCaHb))(PEt3)2]) and is accompanied by the formation of the free thiophene. Under comparable conditions, the amount of desulfurization decreases in the order BT complex 2 (73%) > DBT complex 1 (50%) > T complex 3 (ca. 4%). These hydride reactions show the novel feature that the C-S bond is cleaved as well as the Pt-C bond; possible mechanisms for the platinum and for the known nickel- and hydride-promoted hydrodesulfurization (HDS) reactions are discussed.
Ligand effects on the rates of protonolysis and isotopic exchange for platinum (II) alkyls
Holtcamp, Matthew W.,Labinger, Jay A.,Bercaw, John E.
, p. 117 - 125 (1997)
The protonolysis/deuterolysis of complexes L2PtRX (L = phosphorus ligand, R = alkyl group, X = anionic ligand) has been investigated as a mechanistic probe of the reverse reaction, activation of alkanes by Pt(II). Trans-(Et3P)2PtMeX (X- = triflate (OTf-), F-, NO3-) solvolyze in acidic CD3OD, forming [trans-(Et3P)2PtMe(CD3OD)]+ which reacts slowly with DOTf at room temperature liberating CH3D. In dichloromethane, trans-(Et3P)2PtMe(OTf) reacts with HOTf at low temperatures (-70 to -20°C) to give (Et3P)2PtMe(H)(OTf)2 in rapid equilibrium with the reagents, while at higher temperatures rapid methane loss is preceded by extensive deuterium incorporation (with DOTf) into the Pt(II) methyl group. Upon treatment with acid in CD3OD, trans-(Et3P)2PtMeX (X = Cl, Br) also undergo H/D exchange before elimination of methane, while trans-(Et3P)2PtMeI, (depe)Pt(CH3)2 (depe=1,2-bis(diethylphosphino)ethane) and cis-[(MeO)3P]PtMeCl do not. The a hydrogens of trans-(Et3P)2PtRCl (R=Me, Et, Bz) exchange with deuterium in CD3OD/DOTf with rates following the order Bz3P)2Pt(CH2CMe3)Cl which yields (CH3)3CCH2D. These trends are interpreted in terms of effects on relative stabilities of key intermediates, Pt(IV) alkyl hydrides and Pt(II) alkane sigma complexes.
A dynamic disorderlinked reversible phase transition in a new chloroform solvate of cisdichloridobis(triethylphosphane)platinum(II)
Dillon, Keith B.,Howard, Judith A. K.,Monks, Philippa K.,Probert, Michael R.,Shepherd, Helena J.
, p. m111-m114 (2011)
The title compound, cisdichloridobis(triethylphosphane)platinum(II) chloroform monosolvate, [PtCl2(C6H15P) 2]·CHCl3, has been obtained from ligand scrambling in the cis-[PtCl2(Cyp2PCl)(PEt3)] (Cyp = cyclopentyl) system in CHCl3 solvent. Unlike the two previously reported unsolvated polymorphs, which are both monoclinic, the compound crystallizes in an orthorhombic setting. Furthermore, the system exhibits a reversible temperaturedependent structural phase transition, coupling a reduction in anisotropic displacement parameters and a reduction in crystallographic symmetry on cooling. The hightemperature phase adopts space group Pnma with the complex and solvent molecules sitting across a crystallographic mirror plane (Z′ = 0.5). The low-temperature phase adopts the space group P212121 with Z′ = 1.
Towards a catalytic hydrogenolysis of silicon-silicon bonds: Formation of Si-H bonds from disilanes and H2 at platinum
Roscher, Anja,Bockholt, Andreas,Braun, Thomas
, p. 1378 - 1382 (2009/06/06)
Reactions of the disilanes Cl2MeSiSiMeCl2, ClMe 2SiSiMe2Cl and Me3SiSiMe3 led to the products of oxidative addition cis-[Pt(SiMeCl2)2(PEt 3)2] (2
Multiple coordination modes of hemilabile 3-dimethylaminopropyl chalcogenolates in platinum(II) complexes: Synthesis, spectroscopy and structures
Dey, Sandip,Jain, Vimal K.,Butcher, Ray J.
, p. 2653 - 2660 (2008/10/09)
The reactions of N,N-dimethylaminopropyl chalcogenolates with platinum(II) compounds have been carried out and complexes of the types [PtCl(ECH2CH2CH2NMe2)]2 (1) (E = S (1a) and Se (1b)), [Pt(ECH2CH2CH2NMe2)2]n (2) (E = S (2a) and Se (2b)), [(PtCl2)2{(Me2NCH2CH2CH2E)2}]n (3), [PtX(SeCH2CH2CH2NMe2)]2 (4) (X = SePh (4a) and OAc (4b)) and [PtCl(ECH2CH2CH2NMe2)(PR3)]n (5) (E = S, Se, Te) have been isolated. These complexes have been characterized by elemental analysis, IR, UV-Vis, NMR (1H, 13C, 31P, 77Se, 195Pt) spectroscopy and FAB mass spectral data. The structures of [PtCl(SeCH2CH2CH2NMe2)]2 (1b) and [PtCl(SCH2CH2CH2NMe2)(PPr3)]2 (5a) have been established by single crystal X-ray diffraction data. Both the molecules have dimeric structures. In 1b, two platinum atoms are held together by symmetrically bridging Se atoms of the chelating selenolate groups. In 5a, two thiolates form a four-membered Pt2S2 bridge with dangling NMe2 groups.
