65097-96-3Relevant academic research and scientific papers
Thiosaccharinate binding to palladium(II) and platinum(II): Synthesis and molecular structures of sulfur-bound complexes [M(κ1-tsac) 2(κ2-diphosphane)]
Al-Jibori, Subhi A.,Al-Jibori, Mohamed H.S.,Hogarth, Graeme
, p. 117 - 123 (2013/05/22)
Palladium(II) and platinum(II) thiosaccharinate complexes [M(κ1-tsac)2{κ2-Ph 2P(CH2)nPPh2}] (M = Pd, Pt; n = 1-4) have been prepared, palladium complexes from reaction of [Pd(tsac) 2]·H2O with diphosphanes and platinum complexes from addition of thiosaccharin to [PtCl2{κ2-Ph 2P(CH2)nPPh2}] in the presence of triethylamine. All complexes have been fully characterized and the crystal structures of [Pd(κ1-tsac)2(κ2- dppp)] (n = 3) and [Pt(κ1-tsac)2(κ 2-dppm)] (n = 1) have been determined confirming that thiosaccharinate ligands are S-bound. The larger ring complexes (n = 3, 4) are fluxional in solution being attributed to the conformational flexibility of the diphosphane backbones The bis(diphosphane) complexes, [M(κ1- tsac)2(κ1-dppm)2] (M = Pd, Pt), have also been prepared upon treatment of [Pd(tsac)2]·H2O with two equivalents of dppm or addition of thiosaccharin to [Pt(κ2-dppm)2]Cl2 in the presence of triethylamine in which the diphosphanes bind in a monodentate fashion. Both are highly fluxional in solution, changes in the 31P{1H} NMR spectra as a function of temperature being interpreted as the exchange of bound and unbound phosphorus atoms.
Synthesis and characterisation of 2,2-bis(hydroxymethyl)-1,3-diselenolato metal(II) complexes bearing various phosphanes
Niksch, Tobias,Goerls, Helmar,Friedrich, Manfred,Oilunkaniemi, Raija,Laitinen, Risto,Weigand, Wolfgang
, p. 74 - 94 (2010/04/01)
An improved synthesis of 4,4-bis(hydroxymethyl)-1,2-diselenolane and the complexation properties of the corresponding diselenolato dianion to group-10 metals are reported. We describe an efficient and straightforward procedure that bypasses the isolation of the malodorous and airsensitive diselenol and starts with the diselenide appropriate group-10 metal complex bearing phosphane and chlorido ligands. A series of complexes with various monoand bidentate phosphanes is prepared and characterised by multinuclear NMR spectroscopy, mass spectrometry, and elemental analysis. Furthermore, the structure of most complexes is studied by single-crystal X-ray diffraction to establish their supramolecular arrangement in the solid state. Consequently, several group-10 metal complexes with P-M-P angles (bite angles) in the range from 71-108° are investigated. The use of the sterically demanding bridging phosphane 4,5-bis(diphenylphosphanyl)-9,9-dimethylxanthene, which exhibits a large bite angle yields a mixture of a di- and trinuclear complex. While the platinum-containing complexes are proven to be rather stable, the palladium and nickel analogues tend to decompose. Especially, the nickel complexes were found to be sensitive against: oxidation. This circumstance leads to the formation of the so far unknown 1,8-bis(diphenylphosphanyl)naphthalene monooxide, the formation and structure of which could be confirmed from NMR spectroscopic data and single-crystal X-ray diffraction.
Mechanistic insight into the protonolysis of the Pt-C bond as a model for C-H bond activation by platinum(II) complexes
Romeo, Raffaello,D'Amico, Giuseppina
, p. 3435 - 3446 (2008/10/09)
The kinetic and NMR features of the protonolysis reactions on platinum(II) alkyl complexes of the types cis-[PtMe2L2], [PtMe 2(L-L)], cis-[PtMeClL2], and [PtMeCl(L-L)] (L = PEt 3, P(Pri)3, PCy3, P(4-MePh) 3, L-L = dppm, dppe, dppp, dppb) in methanol suggest a rate-determining proton attack at the Pt - C bond. In contrast, a multistep oxidative-addition - reductive-elimination mechanism characterizes the methane loss on protonation of the corresponding trans-[PtMeClL2] species. Tools that were particularly diagnostic in suggesting different reaction pathways for the two systems were (i) the different results of kinetic deuterium isotope experiments, (ii) the detection or absence of Pt(IV) hydrido alkyl intermediate species by low-temperature 1H NMR experiments, and (iii) the detection or absence of isotope scrambling and incorporation of deuterium into Pt - CH3, combined with the loss of a range of CH nDn-4 isotopomers. For all systems, the rates of protonolysis are retarded by ligand steric congestion, accelerated by ligand electron donation, and almost unaffected by the chain length along the series of chelate complexes. A straight line correlates the rates of protonolysis of cis-dialkyl and cis-monoalkyl complexes, the difference in reactivity between the two systems being almost 5 orders of magnitude (slope of the line = 6 × 104). Factors controlling the dichotomy of behavior between complexes of different geometry have been taken into consideration. Application of the principle of microscopic reversibility suggests the reason why platinum complexes with nitrogen donor ligands appear to be far more efficient than platinum phosphane complexes in activating the C-H bond.
Effect of ring size on NMR parameters: Cyclic bisphosphine complexes of molybdenum, tungsten, and platinum. Bond angle dependence of metal shieldings, metal-phosphorus coupling constants, and the 31P chemical shift anisotropy in the solid state
Lindner, Ekkehard,Fawzi, Riad,Mayer, Hermann August,Eichele, Klaus,Hiller, Wolfgang
, p. 1033 - 1043 (2008/10/08)
The 31P chemical shift tensors of bis(phosphine) complexes of the type [M] [Ph2P(CH2)nPPh2] ([M] = (OC)4Mo, (OC)4W, Cl2Pt; n = 1-5) and of fac-(OC)3Mo[PPh(CH2CH2PPh2) 2] were determined by solid-state NMR techniques and correlated with structural features of the compounds. δ(31P), 1JM-P, and δ(M) show a dependence on the ring size in the solution NMR spectra of the four- to six-membered chelates; for larger rings this dependence vanishes. A model for the orientation of the 31P shift tensor principal components within the molecular frame is proposed. Each tensor component displays a different dependence on the ring size; the isotropic shift is dominated by the component perpendicular to the ring plane. Changes in this component are explained in terms of variations of the M-P-C angles. Generally speaking, the behavior of each of the tensor components must be regarded as a complex interplay of all six bond angles at phosphorus. The crystal structure of (OC)4W[Ph2P(CH2)4PPh2] (2d) was determined by X-ray diffraction. Crystals of 2d are monoclinic, space group P21/n, a = 1202.8 (1) pm, b = 1531.8 (1) pm, c = 1654.1 (2) pm, β = 104.72 (1)°, and Z = 4.
Stability of (Chloromethyl)platinum(II) Complexes
McCrindle, Robert,Arsenault, Gilles J.,Gupta, Anuradha,Hampden-Smith, Mark J.,Rice, Richard E.,McAlees, Alan J.
, p. 949 - 954 (2007/10/02)
The stabilities of , (cod = cycloocta-1,5-diene) and a range of phosphine-containing mono- and cis-bis-(chloromethyl)platinum(II) complexes have been investigated in deuteriochloroform at room temperature.Some of the bis(chloromethyl) derivatives appear to be indefinitely stable (cod and chelating arylphosphines), others suffer very slow decomposition to the dichlorides (non-chelating arylphosphines), and the remainder decompose relatively rapidly, and cleanly, to the dichlorides plus ethylene (alkylphosphines, non-chelating faster than chelating).Rapid decomposition of the arylphosphine complexes can be induced by adding hexafluoroisopropyl alcohol to the deuteriochloroform solutions.Attempts to generate 2> by addition of P(C6H11)3 to resulted in the formation of cis--+(C6H11)3>Cl2>; a mechanism is proposed.All cis-mono(chloromethyl) derivatives studied appear to be indefinitely stable.In contrast, the trans-mono(chloromethyl) complexes, although stable in very dry solvent, undergo decomposition in the presence of moisture to the corresponding hydrides plus formaldehyde; a mechanism is proposed.The hydrides undergo subsequent conversion into a mixture of cis and trans dichlorides.
