Interference by phosphine decomposition in oxidative additions of aryl halides to methyl-, and trimethylsilyl-tris(triphenylphosphine)cobalt

The oxidative addition of aryl halides, ArX, to [Ph₃P]₃CoCH₃ yield ArAr and ArCH₃ when Ar = 4-CH₃C₆H₄, but exclusively ArCH₃ for 1- and 2-bromo-naphthalene and 4-bromobiphenyl. Decomposition of the phosphine ligand in [Ph₃P]₃CoCH₃ interfers with these reactions to varying extents depending on the relative rates of the reactions; ArCl mostly gives PhPh with some ArPh and ArAr; ArI gives mostly ArAr; ArBr shows intermediate behaviour. Other cobalt compounds such as [Ph₃P]₃CoSi[C₃]₃, [Ph₂PCH₃]₃CoCH₃, [Ph₂PCH₃]₃CoPh and [Ph₂PGe(CH₃)₃]₃CoCH₃ and several other organic halides examined show a low activity in the oxidative addition.     

The reversible adduct formation of group III trialkyls with relatively involatile phosphines; X-ray crystal structures of (Me3M)2·(Ph2PCH2)2 (M = Al,Ga, In) and (Me3Al)3·(Ph2PCH2CH2)2PPh

The following adducts of Group III trialkyls with phosphines have been prepared, either by direct reaction in hydrocarbon solution or by displacement of ether from the metal trialkyl etherate: Me₃M·PPh₃ (M = Ga, In); Me₃In·P(2-MeC₆H₄)₃; (R₃M)₂·(Ph₂PCH₂)₂ (R = Me, M = Al, Ga, In; R = Et, M = Ga, In; R = Buⁱ, M = Al); (Me₃M)₃·(Ph₂PCH₂CH₂)₂PPh (M = Al, Ga, In) and (Me₃M)₄·(Ph₂PCH₂CH₂PPhCH₂)₂ (M = Al, Ga, In). The compounds were analysed by ¹H and ³¹P NMR spectra of (Me₃M)₂·(Ph₂PCH₂)₂ (M = Ga, In) showed little change between 193 K and room temperature. Thermal dissociation of the adducts in vacuo gave the free metal trialkyl with no detectable contamination by the respective phosphine. Crystals of (Me₃M)₂·(Ph₂PCH₂)₂ (M = Al, Ga, In) are iso-structural and the molecules contain two distorted tetrahedral metals bridged by the (Ph₂PCH₂)₂; the MP distances are 2.544(4), 2.546(4) and 2.755(4) Å, respectively. The X-ray crystal structure of (Me₃Al)₃·(Ph₂PCH₂CH₂)₂PPh shows the molecule to contain distorted tetrahedral aluminium atoms bonded to each of the three phosphorus atoms, with AlP distances of 2.536(9) and 2.510(9) Å for the terminal and central moieties, respectively; the unit cell contains two such molecules plus one benzene molecule (the crystallizing solvent).     

Mixed ligand transition metal complexes of tertiary phosphines and 5-phenyl-l,3,4-oxadiazole-2-thione

Transition metal complexes containing two types of ligands: 5-phenyl-1,3,4-oxadiazole-2-thione ion (L) and tertiary phosphines, have been prepared. The complexes, [ML₂A₂] [M = Pd or Pt; A = PPh₃ or Ph₂PCH₂CH₂P(O)Ph₂] and [ML₂B] (M = Co, Ni, Pd or Pt; B = Ph₂PCH₂PPh₂ or Ph₂PCH₂CH₂PPh₂), were characterized by elemental analysis, molar conductance, i.r., u.v.–vis., ³¹P-n.m.r., magnetic susceptibility measurements and mass spectra.     

Synthesis and Crystal Structure of CpFe(CO)l(η1-Ph2PCH2P(O)Ph2)

CpFe(CO)I(η¹-Ph₂PCH₂P(O)Ph₂) 2 was obtained in small yield from reaction of [CpFe(CO)]₂[μ-(Ph₂P)₂CH₂] with diiodine in benzene, or prepared in 82% yield on treating CpFe(CO)I(η¹-Ph₂PCH₂PPh₂) 1 with H₂O₂. Compound 2 crystallizes in the space group P2₁/n, with a = 8.441(2) Å, b = 10.054(2) Å, c = 33.343(8) Å, β = 92.33(2)°, Z = 4, V = 2827(1) ų, R_F = 0.057, and R_w = 0.056.     

Synthesis of sulphonated aminomethylphosphines and some nickel(II), palladium(II), platinum(II) and rhodium(I) complexes. Crystal structure of [Et3NH][(Ph2PCH2)2 N(CH2)2SO3]

Summary Aminoalkanesulphonic acids H₂N(CH₂) _n SO₃H, (n = 1, 2 or 3) react with phosphonium salts [R₂P(CH₂OH)₂]Cl (R = Ph or Cy, Cy = cyclohexyl) in the presence of Et₃N to give the sulphonated aminomethylphosphines [Et₃NH] [(R₂PCH₂)₂N(CH₂) _n SO₃] (R = Ph, n = 1, 2 or 3; R = Cy, n = 1). The single crystal X-ray structure of [Et₃NH] [(Ph₂PCH₂)₂N(CH₂)₂SO₃] has been determined. Some Ni^II, Pd^II, Pt^II and Rh^I complexes of the phosphines have been prepared.     

Study on the reactions of the dinitrogen complexestrans-[M(N2)2(Ph 2PCH2CH2PPh 2)2] (M=Mo or W) with ethyldiazoacetate: Formation of an Azo compound and of a phosphazene species

Complextrans-[Mo(N₂)₂(dppe)₂] (dppe=Ph ₂PCH₂CH₂PPh ₂) reacts with NN=CHCOOEt in benzene solution to afford benzene-azomethane,Ph-N=N-CH₃, as the main organic product. However, the phosphazene speciesPh ₂P(N₂CHCOOEt)(CH₂CH₂)P(N₂CHCOOEt)Ph ₂ is formed by irradiating aTHF solution oftrans-[W(N₂)₂(dppe)₂] in the presence of ethyldiazoacetate; in moist solution, the phosphazene bonds undergo a partial hydrolysis, and the phosphonium species [Ph ₂P(NHNCHCOOEt)(CH₂CH₂)P(NHNCHCOOEt)Ph ₂]²⁺ appears to be formed.

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Untersuchungen zu den Reaktionen der Distickstoff-Komplexetrans-[M(N₂)₂(Ph ₂PCH₂CH₂PPh ₂)₂] (M=Mo oder W) mit Ethyldiazoacetat: Die Bildung einer Azoverbindung und eines Phosphazens

Zusammenfassung Die Komplexetrans-[Mo(N₂)₂(dppe)₂] (dppe=Ph ₂PCH₂CH₂PPh ₂) reagieren mit NN=CHCOOEt in benzolischer Lösung zuPh-N=N-CH₃ als organischem Hauptprodukt. Andererseits wird bei der Bestrahlung vontrans-[W(N₂)₂(dppe)₂] inTHF-Lösung in der Gegenwart von Ethyldiazoacetat das PhosphazenPh ₂P(N₂CHCOOEt)(CH₂CH₂)P(N₂CHCOOEt)Ph ₂ gebildet; in feuchter Lösung erleidet die Phosphazen-Bindung eine teilweise Hydrolyse und die Phosphonium-Spezies [Ph ₂P(NHNCHCOOEt)(CH₂CH₂)P(NHNCHCOOEt)Ph ₂]²⁺ scheint gebildet zu werden.

     

Metal Ions in Biological Systems,Volume 4. Metal Ions as Probes; : edited by Helmut Sigel,Marcel Dekker,New York, 1974, xii + 261 pages, $24.75.

Trends in ³¹P NMR coordination shifts for the complexes M(CO)₃BrL₂, [M(CO)₃L₂(NCMe)]⁺, MeC₅H₄Mn(CO)L₂ and [MeC₅H₄Mn(CO)₂]₂L₂ (M = Mn and Re;L₂ = Ph₂PCH₂PPh₂, Ph₂PCH₂CH₂PPh₂ and Ph₂PCH₂CH₂AsPh₂) are discussed.     

Synthesis and characterization of diiron ethanedithiolate complexes with monosubstituted phosphine ligands

Reactions of (μ-edt)Fe₂(CO)₆ (edt = SCH₂CH₂S) (1) with the monophosphine ligands Ph₂PCH₂Ph, Ph₂PC₆H₁₁, Ph₂PCH₂CH₂CH₃, or P(2-C₄H₃O)₃ in the presence of Me₃NO?2H₂O afforded (μ-edt)Fe₂(CO)₅L [L = Ph₂PCH₂Ph, 2; Ph₂PC₆H₁₁, 3; Ph₂PCH₂CH₂CH₃, 4; P(2-C₄H₃O)₃, 5] in 70–88% yields. Complexes 2–5 were characterized by spectroscopy and single crystal X-ray diffraction analysis. The phosphorus of 2–5 is in an apical position of the distorted octahedral geometry of iron.     

On the Reactivity of the Platina‐β‐diketone [Pt2{(COMe)2H}2(μ‐Cl)2] Towards Ph2PCH2CH2CH2SOxPh (x = 0, 2)

The reaction of the electronically unsaturated platina‐β‐diketone [Pt₂{(COMe)₂H}₂(μ‐Cl)₂] ( 1 ) with Ph₂PCH₂CH₂CH₂SPh ( 2 ) leads selectively to the formation of the acetyl(chlorido) platinum(II) complex (SP‐4‐3)‐[Pt(COMe)Cl(Ph₂PCH₂CH₂CH₂SPh‐κP,κS)] ( 4 ) having the γ‐phosphinofunctionalized propyl phenyl sulfide coordinated in a bidentate fashion (κP,κS). In boiling benzene complex 4 undergoes decarbonylation yielding the methyl(chlorido) platinum(II) complex (SP‐4‐3)‐[PtMeCl(Ph₂PCH₂CH₂CH₂SPh‐κP,κS)] ( 6 ). However, the reaction of 1 with the analogous γ‐diphenylphosphinofunctionalized propyl phenyl sulfone Ph₂PCH₂CH₂CH₂SO₂Ph ( 3 ) affords the acetyl(chlorido) platinum(II) complex (SP‐4‐4)‐[Pt(COMe)Cl(Ph₂PCH₂CH₂CH₂SO₂Ph‐κP)₂] ( 5 ). In boiling benzene complex 5 undergoes a CO extrusion yielding (SP‐4‐4)‐[PtMeCl(Ph₂PCH₂CH₂CH₂SO₂Ph‐κP)₂] ( 8 ) whereas in presence of 1 the formation of the carbonyl complex (SP‐4‐3)‐[PtMeCl(CO)(Ph₂PCH₂CH₂CH₂SO₂Ph‐κP)] ( 7 ) is observed. Addition of Ag[BF₄] to complex 5 leads to the formation of the cationic methyl(carbonyl) platinum(II) complex (SP‐4‐1)‐[PtMe(CO)(Ph₂PCH₂CH₂CH₂SO₂Ph‐κP)₂][BF₄] ( 9 ). All complexes were characterized by microanalysis and NMR spectroscopy (¹H, ¹³C, ³¹P) and complexes 4 and 6 additionally by single‐crystal X‐ray diffraction analyses.     

Ditertiary phosphine complexes of (ν-allyl)dicarbonylmolybdenum(II) and -tungsten(II)

Compounds of the type [XM(CO)₂(ν-allyl)L₂] (where X = Cl and Br; M = Mo and W; L₂ = Ph₂PCH₂PPh₂ and Ph₂ PCH₂CH₂PPh₂) have been prepard from the corersponding MeCN complexes. The spectral properties of these compounds and the effects of chelate rign size on ³¹P coordination shifts and J(¹⁸³W—³¹P) have been investigated.     

Platinum and rhodium complexes in which diphenylphosphino(methylthio)methane acts as a monodentate,chelated or bridging ligand

Reaction of [PtCl₂(cod)] with Ph₂PCH₂SCH₃ yields cis-[PtCl₂(Ph₂PCH₂-SCH₃)₂] which, on treatment with AgBF₄, is converted to [PtC](Ph₂PCH₂SCH₃)₂]-BF₄, in which one of the ligands is chelated. With [Pt(dba)₂], cis-[Pt(Cl₂(Ph₂PCH₂-SCH₃)₂] reacts to give the platinum(I) complex [Pt₂Cl₂(μ-Ph₂PCH₂SCH₃)₂], which contains a platinum-platinum bond. The terminal chlorides may be replaced by iodide, but the complex is cleaved by carbon monoxide. [Rh₂(μ-Cl)₂(CO)₄] reacts with Ph₂PCH₂SCH₃ to produce [Rh₂Cl₂(CO)₂(μ-Ph₂PCH₂SCH₃)₂], whereas with Ph₂PCH₂CH₂SCH₃ it yields [RhCl(CO)(Ph₂PCH₂CH₂SCH₃)]. A ligand exchange reaction occurs between cis-[PtCl₂(Ph₂SCH₃)₂] and [Rh₂(μ-Cl)₂(CO)₄] to give cis-[PtCl₂(CO)(Ph₂PCH₂SCH₃)] and [Rh₂Cl₂(CO)₂(μ-Ph₂PCH₂SCH₃)₂].     

Immobilization, Characterization, and Preliminary Reactivity Studies of Halfsandwich Ruthenium Complexes on Silica

Summary. The complexes [RuCp(CH₃CN)₂(Ph₂PCH₂CH₂Si(OMe)₃)]PF₆ and [RuCp(CH₃CN) (Ph₂PCH₂CH₂Si(OMe)₃)₂]PF₆ were obtained in good yields by treatment of [RuCp(CH₃CN)₃]PF₆ with 1 and 2 equivs of Ph ₂PCH₂CH₂Si(OMe)₃. Both free Ph ₂PCH₂CH₂Si(OMe)₃ and the two complexes were grafted onto the surface of powdered silica. The surface coverage was determined independently by ³¹P solid state NMR and IR spectroscopy. IR data revealed that for Ph ₂PCH₂CH₂Si(OMe)₃ and the complexes 52, 52, and 18 molecules, respectively, were immobilized per 100nm² of SiO₂ surface. Similar values were obtained from ³¹P MAS NMR measurements. With the immobilized first complex the catalytic redox isomerization of allyl alcohol to propanal has been studied by means of IR spectroscopy and ¹H NMR spectroscopy showing the quantitative formation of aldehyde. While in the first cycle satisfactory turnover numbers were achieved, the subsequent cycles showed only low conversions to aldehyde presumably due to decomposition of the complex. The immobilized second complex was catalytically inactive.Received February 25, 2003; accepted March 24, 2003 Published online August 18, 2003     

The electrochemistry of organotransition-metal complexes : II. Formation and reactivity of the radical cations [trans-Fe(CO3(PR3)2]+ and [Fe(CO)3 (Ph2 PCH2 CH2 PPh2)]+

[Fe(CO)₃ L₂] (L = PPh₃, PPh₂Me, P(OPh)₃ or P(NMe₂)₃; L₂ = Ph₂ PCH₂ CH₂ PPh₂⁺) undergo reversible one-electron oxidations to give the radical cations [Fe(CO)₃L₂]⁺ which have been studied by IR and ESR spectroscopy.     

Synthesis of palladium complexes with bis(diphenylphosphinomethyl)amino ligands: A catalyst for the Heck reaction of aryl halide with methyl acrylate

A series of ligands, (Ph₂PCH₂)₂NR (R = -CH₃) (1), -C(CH₃)₃, (2) -m-C₆H₄SO₃Na (3), and their Pd(II) complexes have been synthesized under nitrogen atmosphere using Schlenk method. All compounds were characterized using elemental analysis and spectroscopic techniques (AAS, NMR (¹H, ³¹P)). Based on the analysis the complexes have been proposed as in square planar geometry. The Pd(II) complexes were applied to the Heck reaction of aryl halide (Br, Cl) with methyl acrylate. The results have exhibited that complexes [PdCl₂((Ph₂PCH₂)₂NCH₃)] (4) and [PdCl₂((Ph₂PCH₂)₂NC(CH₃)₃)] (5) have shown higher turnover numbers (TON) than complex [PdCl₂(Ph₂PCH₂)₂N-m-C₆H₄SO₃Na] (6).     

Preparation and crystallographic characterization of Pd(II) complexes containing imidobis(diphenylthiophosphinato) ligand

The reactions of PdCI₂(L-L) [L-L = Ph₂PCH₂PPh₂(dppm), Ph₂PCH₂CH₂PPh₂(dppe) and Ph₂PCH₂CH₂CH₂PPh₂(dppp)] with equivalent amount of (Ph₂P(S)NHP(S)Ph₂)(dppaS₂) gave the complexes [Pd(L-L)(dppaS₂-H)]ClO₄ [L-L = dppm (1), dppe (2), dppp (3)]. The different synthetic route was used for complex 2 by using of Pd(dppe)Cl₂ and K[N(PSPh₂)₂] as starting materials (2a). All of these complexes have been characterized ³¹P{¹H} NMR, IR and elemental analyses. The complexes 2, 2a and 3 were crystallographically characterized. The coordination geometry around the Pd atoms in these complexes distorted square planar. Six membered dppaS₂-H rings are twist boat conformations in three complexes.     

Carbonyl complexes of manganese(I) with chelating phosphino-alkyl or -acyl ligands. Crystal and molecular structure of [Ph2PCH2CH2(O)CMn(CO)2(dppm)l

The phosphine Ph₂PCH₂CH₂Cl reacts with fac-[XMn(CO)₃(dppm)] (X = Cl or Br) in refluxing toluene to give the complexes cis,cis-[XMn(CO)₂(dppm)(Ph₂PCH₂CH₂Cl)] (I). Treatment of those species with Na amalgam in THF leads to the alkyl complex [Ph₂$\text{PCH}{}_2\text{CH}{}_2\text{M}$n(CO)₂(dppm)] (II), which does not react with CO under normal conditions but can be converted into cis,cis-[ClMn(CO)₂(dppm)(PPh₂Et)] by reacting with HCl (g) in ether. If the reduction of I with Na/Hg is carried out in the presence of CO the compound cis-[Ph₂$\text{PCH}{}_2\text{CH}{}_2\text{(O)CM}$n(CO)₂(dppm)] (III) is obtained. The latter has also been prepared directly from fac-[BrMn(CO)3(dppm)], Ph₂PCH₂CH₂Cl, and Na/Hg in THF, and characterized by X-ray crystallography. The crystals are monoclinic, space group P2₁/n; refinement gave R = 0.053 for 2593 reflections with I ? 2.5σ(I). The reaction of the complex fac-[O₃ClOMn(CO)₃(dppm)] with Ph₂PCH₂CH₂Cl in Cl₂CH₂ gives the salt fac-[Mn(CO)₃(dppm)(Ph₂PCH₂CH₂Cl)]ClO₄ which isomerizes to mer-[Mn(CO)₃(dppm)(Ph₂PCH₂CH₂Cl)]ClO₄ in boiling butanol. Both cationic carbonyl complexes give the acyl species III upon reduction with Na amalgam.     

Electrochemistry of coordination compounds: Part XIV. Polarographic behaviour of d8 ruthenium nitrosyl complexes

The voltammetric behaviour of the new complex, [Ru(NO)(Ph₂PCH₂CH₂CH₂PPh₂)₂]⁺, has been studied in 1,2-dimethoxyethane and the results compared with those obtained in the analogous reduction of [Ru(NO)(Ph₂PCH₂PPh₂)₂]⁺. The reduction proceeds in two reversible, one-electron steps. Stepwise reduction of these cationic complexes leads to two reversible, one-electron steps. Stepwise reduction of these cationic complexes leads to anionic complexes with formal oxidation number (?II) through the intermediate state which, in the case of Ph₂PCH₂CH₂PPh₂ ligand, is unstable and decays via a disproportionation pathway. A reduction-oxidation mechanism accounting for the chemical and electrochemical results is proposed.     

Cyanoalkyl complexes of transition metals . : II. Preparation and properties of some platinum complexes containing phosphorus as a donor atom

cis-PtCl(CH₂CN)(PPh₃)₂ was obtained by the reaction of Pt(PPh₃)₄ with ClCH₂CN in acetone. A solution of Pt(PPh₃)₄ and ClCH₂CN in benzene was heated under reflux to give trans-PtCl(CH₂CN)(PPh₃)₂. The reaction of the trans-isomer with Br^?, I^?, Ph₂PCH₂CH₂ PPh₂, Ph₂PCH₂CH₂AsPh₂ and cisPh₂PCHCHPPh₂ has been examined. The trans-influence of a ligand trans to the CH₂CN group seems to be indicated by the ²J(PtH) of the CH₂CN protons. The τ values of trans-PtX(CH₂CN)(PPh₃)₂ and PtX(CH₂ CN)(PP) (X = Cl, Br, I) are related by a linear function.     

Synthesis and characterization of bis(diphenylphosphinomethyl)amino ligands and their Ni(II), Pd(II) complexes: Application to hydrogenation of styrene

Transition metal complexes of Ni(II) and Pd(II) with ditertiary bis(diphenylphosphinomethyl)amino ligands, (Ph₂PCH₂)₂NC(CH₃)₃ ( 1 ) and [(Ph₂PCH₂)Nm‐PhSO₃]Na ( 2 ) (Ph = phenyl), have been synthesized in good yields under nitrogen atmosphere by Schlenk technique. All complexes have been characterized using elemental analyses and spectroscopic techniques such as atomic absorption, FT‐IR, and NMR (¹H, ³¹P). Atomic absorption spectroscopic analysis showed that the reactions of ligands 1 and 2 with NiCl₂ ⋅ 6H₂O and [PdCl₂(COD)] occurred in 1:1 molar ratio. The metal complexes [NiCl₂(Ph₂PCH₂)₂Nm‐PhSO₃Na] ( 4 ) and [PdCl₂(Ph₂PCH₂)₂Nm‐PhSO₃Na] ( 6 ) were found to be soluble in ethanolic and aqueous solutions, as well as slightly soluble in water. Electrochemical behaviors of complexes were investigated by cyclic voltammetry. Catalytic effects of Pd(II) complexes were tested throughout the hydrogenation of styrene to ethylbenzene. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:113–118, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20384     

Low-Dimensional Architectures in Isomeric cis-PtCl2{Ph2PCH2N(Ar)CH2PPh2} Complexes Using Regioselective-N(Aryl)-Group Manipulation

The solid-state behaviour of two series of isomeric, phenol-substituted, aminomethylphosphines, as the free ligands and bound to Pt^II, have been extensively studied using single crystal X-ray crystallography. In the first library, isomeric diphosphines of the type Ph₂PCH₂N(Ar)CH₂PPh₂ [1a–e; Ar = C₆H₃(Me)(OH)] and, in the second library, amide-functionalised, isomeric ligands Ph₂PCH₂N{CH₂C(O)NH(Ar)}CH₂PPh₂ [2a–e; Ar = C₆H₃(Me)(OH)], were synthesised by reaction of Ph₂PCH₂OH and the appropriate amine in CH₃OH, and isolated as colourless solids or oils in good yield. The non-methyl, substituted diphosphines Ph₂PCH₂N{CH₂C(O)NH(Ar)}CH₂PPh₂ [2f, Ar = 3-C₆H₄(OH); 2g, Ar = 4-C₆H₄(OH)] and Ph₂PCH₂N(Ar)CH₂PPh₂ [3, Ar = 3-C₆H₄(OH)] were also prepared for comparative purposes. Reactions of 1a–e, 2a–g, or 3 with PtCl₂(η⁴-cod) afforded the corresponding square-planar complexes 4a–e, 5a–g, and 6 in good to high isolated yields. All new compounds were characterised using a range of spectroscopic (¹H, ³¹P{¹H}, FT–IR) and analytical techniques. Single crystal X-ray structures have been determined for 1a, 1b∙CH₃OH, 2f∙CH₃OH, 2g, 3, 4b∙(CH₃)₂SO, 4c∙CHCl₃, 4d∙½Et₂O, 4e∙½CHCl₃∙½CH₃OH, 5a∙½Et₂O, 5b, 5c∙¼H₂O, 5d∙Et₂O, and 6∙(CH₃)₂SO. The free phenolic group in 1b∙CH₃OH, 2f∙CH₃OH_, 2g, 4b∙(CH₃)₂SO, 5a∙½Et₂O, 5c∙¼H₂O, and 6∙(CH₃)₂SO exhibits various intra- or intermolecular O–H∙∙∙X (X = O, N, P, Cl) hydrogen contacts leading to different packing arrangements.