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Phosphine-substituted and phosphido-bridged metal clusters in homogeneous catalysis I. Synthesis and reactivity of (η5-C5H5)NiM3(μ-H)3(CO)(9-n)Ln (M = Ru, Os, n = 1,2: L = PPh3, PPh2H, PCy3, PEt3) and M3(CO)(12-n)Ln (M = Ru, N = 1-3: L = PPh3,
The complexes (η5-C5H5)NiM3(μ-H)3(CO)(9-n)Ln (M = Ru, Os, n = 1.2: L = PPh3, PPh2H, PCy3, PEt3) and M3(CO)(12-n)Ln (M = Ru, n = 1-3: L = PPh3, PPh2H, PCy3, PEt3; M = Os, n = 1,2: L = PPh3) have been synthesized by new or known procedures.Reacti
Castiglioni, Mario,Giordano, Roberto,Sappa, Enrico
p. 97 - 110
(1988)
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The Trityl-Cation Mediated Phosphine Oxides Reduction
Reduction of phosphine oxides into the corresponding phosphines using PhSiH3 as a reducing agent and Ph3C+[B(C6F5)4]? as an initiator is described. The process is highly efficient, reducing a broad range of secondary and tertiary alkyl and arylphosphines, bearing various functional groups in generally good yields. The reaction is believed to proceed through the generation of a silyl cation, which reaction with the phosphine oxide provides a phosphonium salt, further reduced by the silane to afford the desired phosphine along with siloxanes. (Figure presented.).
Landais, Yannick,Laye, Claire,Lusseau, Jonathan,Robert, Frédéric
supporting information
p. 3035 - 3043
(2021/05/10)

Bis(pertrifluoromethylcatecholato)silane: Extreme Lewis Acidity Broadens the Catalytic Portfolio of Silicon
Given its earth abundance, silicon is ideal for constructing Lewis acids of use in catalysis or materials science. Neutral silanes were limited to moderate Lewis acidity, until halogenated catecholato ligands provoked a significant boost. However, catalytic applications of bis(perhalocatecholato)silanes were suffering from very poor solubility and unknown deactivation pathways. In this work, the novel per(trifluoromethyl)catechol, H2catCF3, and adducts of its silicon complex Si(catCF3)2 (1) are described. According to the computed fluoride ion affinity, 1 ranks among the strongest neutral Lewis acids currently accessible in the condensed phase. The improved robustness and affinity of 1 enable deoxygenations of aldehydes, ketones, amides, or phosphine oxides, and a carbonyl-olefin metathesis. All those transformations have never been catalyzed by a neutral silane. Attempts to obtain donor-free 1 attest to the extreme Lewis acidity by stabilizing adducts with even the weakest donors, such as benzophenone or hexaethyl disiloxane.
Thorwart, Thadd?us,Roth, Daniel,Greb, Lutz
supporting information
p. 10422 - 10427
(2021/05/27)

Reversing Lewis acidity from bismuth to antimony
Investigations on the boundaries between the neutral and cationic models of (Mesityl)2EX (E = Sb, Bi and X = Cl?, OTf?) have facilitated reversing the Lewis acidity from bismuth to antimony. We use this concept to demonstrate a higher efficiency of (Mesityl)2SbOTf(Mesityl)2BiOTf in the catalytic reduction of phosphine oxides to phosphines. The experiments supported with computations described herein will find use in designing new Lewis acids relevant to catalysis.
Balasubramaniam, Selvakumar,Jemmis, Eluvathingal D.,Kumar, Sandeep,Sharma, Deepti,Venugopal, Ajay
supporting information
p. 8889 - 8892
(2021/09/10)

Method for producing alkyl phosphine
The invention provides a method for producing alkyl phosphine, and specifically relates to a method for producing triethyl phosphine. The method comprises the following steps: mixing hydrogen phosphide with ethylene in a solvent, adding a photocatalyst, and carrying out a reaction for 1-12 h under illumination of 20-50 W to obtain triethyl phosphine, wherein the reaction temperature being 0-50 DEGC. According to the invention, under an illumination condition, the photocatalyst easily induces a radical reaction to enhance the reaction activity of hydrogen phosphide and olefin so as to substantially improve the reaction efficiency, the rapid reaction can be performed at the room temperature and the normal pressure, the reaction time is short, the pollution and the toxicity of the catalyst are low, the toxicity of the used solvent is low compared to the toxicity of toluene and the like commonly used in the prior art, the post-treatment is relatively simple, and the yield and the purity of the product are high.
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Paragraph 0044-0059

(2020/11/23)

A Universally Applicable Methodology for the Gram-Scale Synthesis of Primary, Secondary, and Tertiary Phosphines
Although organophosphine syntheses have been known for the better part of a century, the synthesis of phosphines still represents an arduous task for even veteran synthetic chemists. Phosphines as a class of compounds vary greatly in their air sensitivity, and the misconception that it is trivial or even easy for a novice chemist to attempt a seemingly straightforward synthesis can have disastrous results. To simplify the task, we have previously developed a methodology that uses benchtop intermediates to access a wide variety of phosphine oxides (an immediate precursor to phosphines). This synthetic approach saves the air-free handling until the last step (reduction to and isolation of the phosphine). Presented herein is a complete general procedure for the facile reduction of phosphonates, phosphinates, and phosphine oxides to primary, secondary, and tertiary phosphines using aluminum hydride reducing agents. The electrophilic reducing agents (iBu)2AlH and AlH3 were determined to be vastly superior to LiAlH4 for reduction selectivity and reactivity. Notably, it was determined that AlH3 is capable of reducing the exceptionally resistant tricyclohexylphosphine oxide, even though LiAlH4 and (iBu)2AlH were not. Using this new procedure, gram-scale reactions to synthesize a representative range of primary, secondary, and tertiary phosphines (including volatile phosphines) were achieved reproducibly with excellent yields and unmatched purity without the need for a purification step.
Rinehart, N. Ian,Kendall, Alexander J.,Tyler, David R.
supporting information
p. 182 - 190
(2018/02/06)

Organocatalyzed Reduction of Tertiary Phosphine Oxides
A novel selective catalytic reduction method of tertiary phosphine oxides to the corresponding phosphines has been developed. Notably, the reaction proceeds smoothly with low catalyst loadings of 1-5 mol% even at low temperature (70 C). Under the optimized conditions various phosphine oxides could be selectively reduced and the desired phosphines were usually obtained in excellent yields above 90%. Furthermore, we have developed a one-pot reaction sequence for the preparation of valuable phosphinborane adducts. Simple addition of BH3THF subsequent to the reduction step gave the desired adducts in yields up to 99%.
Schirmer, Marie-Luis,Jopp, Stefan,Holz, Jens,Spannenberg, Anke,Werner, Thomas
supporting information
p. 26 - 29
(2016/01/25)

Synthetic method for triethylphosphine
The invention discloses a synthetic method for triethylphosphine and belongs to the field of preparation of compounds. The synthetic method comprises the steps that firstly, under the protection of nitrogen, chloroethane and magnesium chips react in a xylene and tetrahydrofuran mixed solvent with methyl iodide as an initiating agent to obtain ethylmagnesium chloride; secondly, a product obtained in the first step does not need to be purified, is directly added with phosphorus trichloride after being cooled, reacts at a low temperature through stirring and is directly subjected to decompression distillation after the reaction is finished, and a triethylphosphine product with the purity higher than 99% is obtained, and the yield reaches 89.9%. The solvent used in the synthetic method is easy to recycle.
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Paragraph 0014; 0015

(2016/10/10)

Synthesis of a rhodium(i) germyl complex: A useful tool for C-H and C-F bond activation reactions
The dihydrido germyl complex cis,fac-[Rh(GePh3)(H)2(PEt3)3] (2) was synthesized by an oxidative addition of HGePh3 at [Rh(H)(PEt3)3] (1). Treatment of 2 with neohexene generated the rhodium(i) germyl complex [Rh(GePh3)(PEt3)3] (3). Alternatively, treatment of the methyl complex [Rh(CH3)(PEt3)3] (4) with HGePh3 furnished at room temperature also 3. Low-temperature NMR measurements revealed an initial formation of the oxidative addition product fac-[Rh(GePh3)(H)(CH3)(PEt3)3] (5), which transforms into the intermediate complex [Rh(GePh3)(H)(CH3)(PEt3)2] (6) by dissociation of a triethylphosphine ligand. The reductive elimination of methane and coordination of PEt3 afforded the germyl complex 3. Treatment of 3 with CO gave the biscarbonyl complex [Rh(GePh3)(CO)2(PEt3)2] (7). The molecular structures of the complexes 2, 3 and 7 were determined by X-ray crystallography. The germyl complex 3 reacted with 2,3,5,6-tetrafluoropyridine or pentafluorobenzene to furnish the C-H activation products [Rh(4-C5NF4)(PEt3)3] (8) and [Rh(C6F5)(PEt3)3] (9), respectively. The reaction of 3 with hexafluorobenzene or perfluorotoluene gave selectively the C-F activation products 9 and [Rh(4-C6F4CF3)(PEt3)3] (10). Treatment of 3 with pentafluoropyridine resulted in the formation of the C-F activation products 8 and [Rh(2-C5NF4)(PEt3)3] (11) in a 1 : 10 ratio. The two isomeric activation compounds [Rh{(E)-CF=CF(CF3)}(PEt3)3] (12) and [Rh{(Z)-CF=CF(CF3)}(PEt3)3] (13) were obtained in a 3 : 1 ratio by reaction of 3 with hexafluoropropene. On exposure to oxygen the highly air sensitive complex 12 reacts to yield the peroxido-bridged dirhodium complex [Rh{(E)-CF=CF(CF3)}(μ-κ1:η2-O2)(PEt3)2]2 (14). The molecular structure of 14 was determined by X-ray crystallography.
Ahrens, Theresia,Ahrens, Mike,Braun, Thomas,Braun, Beatrice,Herrmann, Roy
p. 4716 - 4728
(2016/03/19)

An acidity scale of tetrafluoroborate salts of phosphonium and iron hydride compounds in [D2]dichIoromethane
Equilibrium constants (K) for reactions between acids and the conjugate base forms of a number of phosphonium salts, [HPR3][BF4], and iron hydrides, [Fe(CO)3H(PR3)2][BF 4], in CD2Cl2 have been determined by means of 31P and 1H NMR spectroscopy at 20°C. The anchor compound chosen for pKCD2Cl2 determinations was [HPCy 3][BF4] with a pKCD2Cl2 value of 9.7, as assigned by literature convention (Cy: cyclohexyl). A continuous scale of pKCD2Cl2 values covering the range from 9.7 to -3 was created and correlated with the ΔH values reported by Angelici and co-workers and literature pKa values. The pKCD2Cl2 values for 15 other hydride or dihydrogen complexes of the iron group elements and of diethyl ether were also placed on this scale. The crystal structures of [Fe(CO) 3H(PCy2Ph)2][BF4] and [Fe(CO) 3(PCy2Ph)2] revealed that the frans-oriented, bulky, unsymmetrical phosphane ligands distort the equatorial plane of the complexes. The acidity of iron carbonyl hydrides is an important feature of the reactions of iron hydrogenase enzymes.
Li, Tianshu,Lough, Alan J.,Morris, Robert H.
p. 3796 - 3803
(2008/02/08)

NOVEL FLUORINATED ALKYLFLUOROPHOSPHORIC ACID SALT OF ONIUM AND TRANSITION METAL COMPLEX
[Problems] To obtain a polymerization initiator (acid generating agent) having excellent power for initiation of cationic polymerization without containing arsenic or antimony. [Means for solution] Provided is a specific onium salt or transition metal complex salt of a fluorinated alkyl fluorophosphoric acid.
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Page/Page column 19-20

(2010/11/25)

Highly atom-economic one-pot formation of three different C-P bonds: General synthesis of acyclic tertiary phosphine sulfides
The reaction of benzothiadiphosphole 1 with an equimolar mixture of R 1MgBr and R2MgBr gave intermediate A′, which, after only 4-5 min, was treated with an equimolar amount of R3MgBr, giving the asymmetric phosphine PR1R2R3 in 45% overall yield (75-80% yield when R1 = R2 and 85-90% yield when R1 = R2 = R3) and the byproduct 6 in 90% yield. The treatment of 6 with PCl3 quantitatively regenerates the starting reagent 1. Treatment of the phosphines with elemental sulfur gave the corresponding sulfides.
Baccolini, Graziano,Boga, Carla,Mazzacurati, Marzia
p. 4774 - 4777
(2007/10/03)

An acidity scale for phosphorus-containing compounds including metal hydrides and dihydrogen complexes in THF: Toward the unification of acidity scales
More than 70 equilibrium constants K between acids and bases, mainly phosphine derivatives, have been measured in tetrahydrofuran (THF) at 20 °C by 1H and/or 31P NMR. The acids were chosen or newly synthesized in order to cover the wide pK(α)(THF) range of 5-41 versus the anchor compound [HPCy3]BPh4 at 9.7. These pK(α)(THF) values are approximations to absolute, free ion pK(a)(THF) and are obtained by crudely correcting the observed K for 1:1 ion-pairing effects by use of the Fuoss equation. The acid/base compounds include 14 phosphonium/phosphine couples, 17 cationic hydride/neutral hydride couples, 9 neutral polyhydride/anionic hydride couples, 14 dihydrogen/hydride couples, and 4 other nitrogen- and phosphorus-based acids. The effects on pK(α) of the counterions BAr'4- and BF4- vs BPh4- and [K(2,2,2-crypt)]+ versus [K(18-crown-6)+ are found to be minor after correcting for differences in inter-ion distances in the ion-pairs involved. Correlations with v(M-H) noted here for the first time suggest that destabilization of M-H bonding in the conjugate base hydride is an important contributor to hydride acidity. It appears that Re-H bonding in the anions [ReH6(PR3)2- is greatly weakened by small increases in the basicity of PR3, resulting in a large increase in the pK(α) of the conjugate acid ReH7(PR3)2. Correlations with other scales allow an estimate of the pK(α)(THF) values of more than 1000 inorganic and organic acids, 20 carbonyl hydride complexes, 46 cationic hydrides complexes, and dihydrogen gas. Therefore, many new acid-base reactions can be predicted and known reactions explained. THF, with its low dielectric constant, disfavors the ionization of neutral acids HA over HB+ and therefore separate lines are found for pK(α)(THF)(HA) and pK(α)(THF)(HB+) when plotted against pK(a)(DMSO) or pK(a)(MeCN). The crystal structure of [Re(H)2(PMe3)5]BPh4 is reported.
Abdur-Rashid, Kamaluddin,Fong, Tina P.,Greaves, Bronwyn,Gusev, Dmitry G.,Hinman, Justin G.,Landau, Shaun E.,Lough, Alan J.,Morris, Robert H.
p. 9155 - 9171
(2007/10/03)

Tertiary phosphine ligand-exchange reactions involving the M(Strictly equivalent to)M quadruply bonded complexes M2Cl4L4, where L = PMe3, PEt3, PBun3 or PMe2Ph
The reactions between M2Cl4L4 complexes and an excess of L or L′ (PMe3, PEt3, PBun3, PMe2Ph or PMePh2) have been studied in [2H8]toluene by 31P-{1H} NMR spectroscopy. The substitutions proceed in a stepwise manner wherein L′ displaces L, except for L′ = Me2PCH2CH2PMe2 (dmpe) which yields Mo2Cl4(dmpe-P)4. No tertiary phosphine in this series is capable of displacing PMe3 from a M2Cl4(PMe3)4 complex but by spin magnetization transfer the degenerate exchange involving Mo2Cl4(PMe3)4 and PMe3 (added in excess) can be detected. The complexes Mo2Cl4(PMe3)4 and Mo2Cl4(PEt3)4 in benzene showed no PMe3 for PEt3 scrambling at +50°C over several days despite the fact that Mo2Cl4(PMe3)4-n(PEt 3)n, where n = 2 or 3, are kinetically inert to ligand redistribution. In the presence of [2H5]pyridine Mo2Cl4(PMe3)4 and Mo2O4(PEt3)4 underwent tertiary phosphine scrambling at 25°C and in neat [2H5]pyridine Mo2Cl4(PMe3)4 revealed the formation of an equilibrium concentration of Mo2Cl4(PMe3)3(py) (py = pyridine) and free PMe3. Under similar conditions Mo2Cl4(PEt3)4 yielded an equilibrium mixture of Mo2Cl4(PEt3)3(py) and Mo2Cl4(PEt3)2(py)2 and free PEt3. From kinetics the ΔH? values are positive in the range +24 to +34 kcal mol-1 and the ΔS? values range from +12 to +28 cal K-1 mol-1. Collectively the data reported are consistent with an interchange dissociative mechanism, Id, wherein M-P bond breaking contributes significantly to the rate-determining step with related values of ΔH? being larger for M = W than M = Mo. The rate dependence on the entering ligand is clearly evident from temperature-dependent studies and leads to varying ΔS? values. The Id mechanism is proposed to involve pre-equilibria between M2Cl4L4 and the entering L′ in an axial site followed by rate-determining M-L displacement. In neat [2H5]pyridine this may be viewed as a solvent-assisted displacement. The present results are discussed in terms of earlier studies from which researchers inferred a simple dissociative process, D, involving M-PR3 bond rupture as the first and rate-determining step.
Chisholm, Malcolm H.,McInnes, Jacqueline M.
p. 2735 - 2743
(2007/10/03)

Monomeric cyclopentadienylnickel methoxo and amido complexes: Synthesis, characterization, reactivity, and use for exploring the relationship between H-X and M-X bond energies
Reactive monomeric amino and methoxo complexes, Cp*Ni(PEt3)NHTol and Cp*Ni(PEt3)OMe, have been synthesized and fully characterized. The former is the first monomeric 18-electron nickel amide to be synthesized and the latter is the first structurally characterized monomeric nickel methoxide complex. The amido complex Cp*Ni(PEt3)NHTol reacts with various Bronsted acids (HX) to produce complexes of the type Cp*Ni(PEt3)X (X = NHAr, OR, Osilica, SR), and compounds with hydridic hydrogens to give the hydridonickel complex Cp*Ni(PEt3)H. The polarity of Ni-N and Ni-O bonds is also demonstrated by reactions with alkali metal salts and trimethylsilyl chloride, and by the crystallographic and NMR characterization of phenol adducts of Cp*Ni(PEt3)OTol. The phosphine ligands in Cp*Ni(PEt3)X (X = OTol, SAr) compounds exchange with PMe3 through an associative mechanism; the rate increases with the electronegativity of X. The thermodynamics of reactions interconverting Cp*Ni(PEt3)X + HX' and Cp*Ni(PEt3)X' + HX have been analyzed using solution equilibrium studies and calorimetry. Instead of being 1:1, the correlation between H-X and M-X bond energies shows a marked preference for nickel binding to more electronegative ligands. This preference is not specific to nickel: examples of similar thermodynamic preferences occur throughout transition metal chemistry. These results may be attributable to a large electrostatic component in the bonding between Ni and X. This qualitative E-C model explains the reactivity, thermodynamics, and phosphine exchange rates of this series of nickel complexes, and may be general to many metal-ligand bonds.
Holland, Patrick L.,Andersen, Richard A.,Bergman, Robert G.,Huang, Jinkun,Nolan, Steven P.
p. 12800 - 12814
(2007/10/03)

Synthesis of group 13 element metallacarboranes and related structure-reactivity correlations
Synthesis, reactivity, and structural characterization studies of a number of group 13 metallacarborane species are described. These include studies of the icosahedral aluminacarborane closo-3-Et-3,1,2-AlC2B9H11 (1a). Compound 1a reacts with Lewis bases to form adducts of the type 2L-1a (L = Lewis base). The reaction of 1a with excess PEt3 results in the rapid formation of endo-10-{AlEt(PEt3)2}-7,8-C2B9H 11 (3). The novel sandwich species commo-3,3′-Al[{exo-8,9-(μ-H)2-AlEt 2-3,1,2-AlC2B9H9)}(3,1,2-AlC 2B9H11)] (4) results from thermal dimerization of 1a. The related sandwich anions [commo-3,3′-Al(3,1,2-AlC2B9H11) 2]- ([5]-) and [commo-3,3′-Ga(3,1,2-GaC2B9H11) 2]- ([6]-) have been prepared. The full details of the synthesis and structural characterization of σ-bonded species nido-6,9-(μ-AlEt-(OEt2))-6,9-C2B8H 10 (8), [Al(η2-6,9-C2B8H10) 2]- ([10]-), and [Al(η2-2,7-C2B6H8) 2]- ([11]-) are reported. The metallacarboranes 3, 4, [5]-, [6]-, 8, [10]-, and [11]- were characterized by a combination of spectroscopic techniques and by single-crystal X-ray diffraction studies. Crystallographic parameters are as follows: 3, P21/n, a = 9.722 (3) A?, b = 16.135 (4) A?, c = 16.984 (5) A?, β = 90.246 (9)°, V = 2652 A?3, Z = 4, R = 0.064, Rw = 0.082 for 3394 independent reflections with I > 3σ(I); 4, P21/n, a = 7.122 (2) A?, b = 27.668 (8) A?, c = 11.629 (3) A?, β = 96.246 (5)°, V = 2288 A?3, Z = 4, R = 0.065, Rw = 0.075, GOF = 2.39 for 2137 independent reflections; Tl[5]·2/3C7H8, P1, a = 11.347 (2) A?, b = 11.748 (2) A?, c = 12.708 (2) A?, α = 92.429 (6)°, β = 90.876 (6)°, γ = 93.343 (5)°, V = 1689 A?3, Z = 3, R = 0.057, Rw = 0.064, GOF = 1.57 for 1941 independent reflections; Tl[6], P1, a = 6.9564 (6) A?, b = 11.0466 (9) A?, c = 12.0287 (10) A?, α = 102.088 (2)°, β = 95.484 (2)°, γ = 94.687 (3)°, V = 894 A?3, Z = 2, R = 0.041, Rw, = 0.054, GOF = 2.03 for 2733 independent reflections; 8·1/2C6H6, A1, a = 13.964 (3) A?, b = 15.966 (4) A?, c = 8.550 (2) A?, α = 92.227 (8)°, β = 86.689 (7)°, γ = 102.060 (8)°, V = 1862 A?3, Z = 4 (reduced cell: a = 8.552 A?, b = 8.909 A?, c = 13.967 A?, α = 99.172°, β = 93.323°, γ = 116.428°, V = 930.9 A?3, Z = 2) R = 0.061, Rw = 0.081, GOF = 2.85 for 2338 independent reflections; [(PPh3)2N][10], P21/c, a = 16.378 (3) A?, b = 18.781 (3) A?, c = 14.806 (3) A?, β = 90.197 (5)°, V = 4554 A?3, Z = 4, R = 0.078, Rw = 0.088, GOF = 2.0 for 2128 independent reflections; [Na][11], P21, a = 10.035 (2) A?, b = 12.433 (3) A?, c = 11.690 (3) A?, β = 111.019 (7)°, V = 1367 A?3, Z = 4, R = 0.049, Rw = 0.059, GOF = 2.08 for 2156 independent reflections. The compound Tl[5]°2/3C7H8 contains the thallium(I)-arene complex Tl(η6-MePh). Compounds 1a and 4 were shown to catalyze the exchange of carborane B-H and arene C-D bonds as well as the polymerization of selected olefins under mild homogeneous conditions. Bonding and the varying degrees of distortion from idealized closo and commo geometries displayed by 3,4, [5]-, and [6]- are discussed. Species 8, [10]-, and [11]- contain Al-C σ-bonded aluminum-carborane connectivities. Compound 8 exhibits rapid exchange of aluminum-coordinated ether in solution, and the compound nido-6,9-(μ-AlEt-(C4H8O))-6,9-C2B 8H10 (9) was prepared by ether exchange of 8 in tetrahydrofuran/toluene. Anion [11]-undergoes rapid enantiomer interconversion in solution at room temperature.
Schubert, David M.,Bandman, Marc A.,Rees Jr., William S.,Knobler, Carolyn B.,Lu, Paul,Nam, Wonwoo,Hawthorne, M. Frederick
p. 2046 - 2061
(2008/10/08)

OBERFLAECHEN-REAKTIONEN 15 Heterogene Dechlorierungen von Phosphorchloriden (X)PCl3 und R-PCl2 an , , x/TiO2> und sowie spektroskopische Evidenz fuer das Entstehen von Diphospha-dicyan PC-CP aus Cl2P-CC-PCl2
Stimulated by the successful generation of unsaturated molecules with low-coordinated phosphorus centers by heterogeneous surface dechlorination, Cl2P-CC-PCl2 is synthesized and characterized by PE and mass spectra.In addition, curls, wool and catalysts x/TiO2> or are tested as potential dechlorinating agents for phosphorus halides like OPCl3, SPCl3, H3C-PCl2, H5C2-PCl2, (H3C)3C-PCl2 or H5C6-PCl2 in a gasflow reactor under reduced pressure and yield, inter alia, the following representative results: due to the thermodynamically favored formation of , or at the Mg surface, P4 is the only gaseous product identified from reactions of OPCl3 and SPCl3 with metal at higher temperatures.On the contrary, passing H3C-PCl2 at 600K over yields a reaction mixture containing P(CH3)3, (H3C)2P-P(CH3)2 (H3C-P)5 and CH4, which suggests an intermediate formation of surface phosphinidenes Mg>.Analogously, the pentamer (H3C-H2C-P)5 can be isolated from ethyldichlorophosphane.Reaction of the evaporated diphospha-cyanogen precursor Cl2P-C-PCl2 with the catalyst produces predominantly PCl3, and P4, but PE and mass spectra provide evidence that also minor amounts of the hitherto unknown molecule PC-CP are formed.
Bock, H.,Bankmann, M.
p. 167 - 191
(2007/10/02)

PRINCIPLES OF PHOSPHORUS CHEMISTRY
An up-to-date concept of bonding in phosphorus compounds has to be based on the reality of molecular states.Molecules, which change their structure with energy, at present are best rationalized in terms of topology and symmetry, effective nuclear potentials and charge distribution.To reduce the complexity of the resulting manifold, comparison of equivalent states of chemical calculations, is strongly recommended.Adding the time-scale, molecular dynamics within the numerous degrees of freedom become important, also as a basis to gain some understanding og the rather complex microscopic reaction pathways of medium-sized molecules.Examples are presented to illustrate the use of spectroscopic "fingerprints" for the analysis and optimization of gasphase reactions as well as the benefit of inherent information on molecular states for the preparative phosphorus chemist.The catalytic dehydrochlorination of alkyldichlorophosphanes RH2C-PCl2 -> RHC=PCl -> R-CP and their dechlorination on magnesium metal surface are discussed in some detail as well as the generation of other unsaturated phosphorus molecules like Cl-P=O, Cl-P=S, ClP(=O)2, Cl-P(=S)2 or H3C-P=CH2.Approximate energy hypersurface calculations for the gasphase equilibrium P4 = 2P2 or for the unexpected dehydration (H3C)2HP=O -> H2O + H3C-P=CH2, which includes chemical activation, provide some insight into microscopic reaction pathways of phosphorus compounds.
Bock, Hans
p. 3 - 53
(2007/10/02)

Evidence for Surface Phosphinidene Intermediates Mg> in the Heterogeneous Dechlorination of Alkyldichlorophosphanes RPCl2 by Mg Metal
The heterogeneous dechlorination of alkyldichlorophosphanes by Mg metal at 600 K yields chemisorbed products which include penta-alkylcyclopentaphosphanes (RP)5, in addition to RnPH(3-n), R2P-PR2, P4, RH, and R-R, and thus provides evidence for surface phosphinidene intermediates Mg>.
Bock, Hans,Bankmann, Martin
p. 1130 - 1132
(2007/10/02)

Syntheses, Reactions, and Molecular Structures of trans-Hydrido(phenylamido)bis(triethylphosphine)platinum(II) and trans-Hydridophenoxobis(triethylphosphine)platinum(II)
The reaction between trans-PtH(NO3)(PEt3)2 and NaNHPh in C6H6 yields the novel hydridoamido complex trans-PtH(NHPh)(PEt3)2 (I).This compound is stable in solution; however, crystals of I decompose within hours at room temperature.At -100 deg C a crystal of I belongs to the monoclinic space group P21/n with a = 11.445(2) Angstroem, b = 13.010(2) Angstroem, c = 14.888(2) Angstroem, β = 104.63(1) deg, V = 2144.9(6) Angstroem3, and Z = 4.Complex I adopts a trans structure, with Pt-N = 2.125(5) Angstroem, indicative of a single bond weakened by the trans-hydride ligand.The Pt-N-Ph angle of 125.5(4) deg and the observation of the H on N in a position expected for trigonal-planar coordination suggest sp2 hybridization about nitrogen.SCF-DV-Xα calculations of the model complex PtH(NH2)(PH3)2 confirm the expected repulsive nature of the interaction between the nitrogen lone-pair orbital and filled d? orbitals on the metal.This interaction is minimized when the nitrogen lone pair lies in the coordination plane of Pt.The reaction between trans-PtH(NO3)(PEt3)2 and excess NaOPh produces trans-PtH(OPh)(PEt3)2 (II).Crystals of II belong to the triclinic space group PI, and at -50 deg C a = 9.477(3) Angstroem, b = 10.617(3) Angstroem, c = 11.641(3) Angstroem, α = 101.61(2), β = 98.28(2) deg, γ = 104.13(2), V = 1089.5(5) Angstroem3, and Z = 2.This complex is isostructural to I with Pt-O = 2.098(9) Angstroem and Pt-O-Ph = 123.6(7) deg.Complex I undergoes rapid insertion of electrophilic substrates such as CO2.COS, and PhNCO into the Pt-NHPh bond in preference to the metal hydride bond.These reactions in C6H6 solvent do not appear to involve free NHPh(1-) as evidenced by the reaction between PtH((15)NHPh)(PEt3)2, which exclusively yields PtH(PEt3)2 as the initial product.Crossover between PtH(NHPh)(PEt3)2 and PtD((15)NHPh)(PEt3)2 to form PtH((15)NHPh)(PEt3)2 and PtD(NHPh)(PEt3)2 occurs slowly (t1/2 ca. 48 h) at room temperature.Electrophiles such aas CH3I and H2O directly attack bound aniline in PtD(NHPh)(PEt3)2 to produce trans-PtDI(PEt3)2 and trans-PtD(OH)(PEt3)2, along with NH(CH3)Ph and NH2Ph, respectively.The electrophilic olefin acrylonitrile inserts into the Pt-N bond to form trans-PtH(PEt3)2 (III).Crystals of III belong to the monoclinic space group P21/c and at 22 deg C a = 14.260(6) Angstroem, b = 14.021(6) Angstroem, c = 13.240(6) Angstroem, β = 107.96(3) deg, V = 2519(3) Angstroem3, and Z = 4.The structure shows a 3-anilinopropionitrile ligand trans to hydride ?-bound to platinum (Pt-C = 2.198(13) Angstroem) by the 2-carbon atom.Complex III undergoes C-H reductive elimination on heating to 70 deg C to produce 3-anilinopropionitrile.Methyl acrylate appears to undergo a similar insertion reaction; however, the organic product is unstable toward elimination in the presence of "Pt(PEt3)2"...
Cowan, Robert L.,Trogler, William C.
p. 4750 - 4761
(2007/10/02)

Kinetic and mechanistic studies on the formation and reactions of early-transition-metal-ketene complexes
A series of complexes of vanadocene or molybdenocene with unsymmetrical ketenes were prepared, either by reaction of the various ketenes with vanadocene itself or by reaction with the molybdenocene phosphine complex (C5H5)2Mo(PEt3). All of the complexes exhibited the expected ketene C=O bonding mode, and all reactions were very specific in their formation of the facial isomer with metallocene fragment located on the side of the smaller ketene substituent. Kinetic studies were used to assess the sensitivity of the incoming vanadocene to steric and electronic effects, with the latter found to dominate. Kinetic studies and activation parameters for reaction of Cp2Mo(PEt3) with EtPhC=C=O indicated a second-order associative mechanism, proposed to involve a nucleophilic attack of the metal center on the ketene central carbon in the rate-limiting step. Lastly, reactions of the bound ketenes with nucleophiles (alkyllithiums or Grignard reagents) proceeded readily to either ketone or aldehyde enolates (the latter via transfer of a β-hydride from the alkyl); the clean production of only Z enolates from the unsymmetrical ketenes is indicative of a metal-mediated internal attack of nucleophile on the bound ketene.
Galante, Julienne M.,Bruno, Joseph W.,Hazin, Paulette N.,Folting, Kirsten,Huffman, John C.
p. 1066 - 1073
(2008/10/08)

Kinetic Studies on the Reaction of Triethyl- and Diethylphenyl-phosphine with Carbon Disulphide in Nitrile Solutions
The kinetics of the reactions of carbon disulphide with triethylphosphine and diethylphenylphosphine are studied in solutions of acetonitrile, propionitrile, isobutyronitrile, benzonitrile, benzyl cyanide, and some of their mixtures.The reaction shows reversible pseudo-first-order kinetics. Activation and equilibrium parameters are discussed in terms of solvent properties.
Campino, Trinidad,Santos, Jose G.,Ibanez, Fernando
p. 1021 - 1024
(2007/10/02)

Tertiary alkylphosphine adducts of Mo2(O2CCF3)4 (Mo - 4Mo)
Mo2(O2CCF3)4 reacts with 2 equiv of PR3 (R = Me, Et, n-Bu) in toluene to give adducts of stoichiometry Mo2(O2CCF3)4·2PR3. These complexes have been characterized by solid-state infrared spectroscopy and variable-temperature 19F and 31P{1H} NMR. A single isomer, with equatorially bound phosphines, is observed in solution at temperatures below ca. -40°C in each case. Previous work on the PMe3 and PEt3 adducts suggested that there were two or more equatorial isomers present in solution at low temperature. The discrepancy between the two studies can be traced to the purity of Mo2(O2CCF3)4, which is usually prepared by metathesis of Mo2(O2CCH3)4 in refluxing trifluoroacetic acid. In our hands, this procedure gives a product contaminated with Mo2(O2C-CF3)3(O2CCH 3). X-ray structural studies on Mo2(O2CCF3)4·2PBu3 show that this complex has a C2h core, which is presumably maintained in solution. The Mo-Mo and Mo-P bond lengths are 2.105 (1) and 2.542 (2) A?, respectively. The differences in solution behavior between homologous M2(O2CCF3)4·2PR3 complexes (M = Mo, W) are discussed and correlated with M-P bond strengths. Phosphine-exchange reactions are used to generate the mixed-phosphine equatorial adducts M2(O2CCF3)4·PEt 3·PBu3 (M = Mo, W) in solution. The electronic absorption spectra of M2(O2CCF3)4·2PMe3 (M = Mo, W) are reported and the δ → δ*, 1Ag → 1Bu transitions are assigned and discussed. Crystal data (at -125°C) for Mo2(O2CCF3)4·2PBu3 are as follows: monoclinic space group I2/a, a = 19.390 (10) A?, b = 10.414 (4) A?, c = 21.790 (11) A?, β = 94.64 (4)°, V = 4385.58 A?3, Z = 4, dcalcd = 1.586 g cm-3.
Santure,Sattelberger
p. 3477 - 3482
(2008/10/08)

Preparation and Structure of Certain Phosphorus-centred Radical Cations
Exposure of dilute solutions of various trivalent phosphorus derivatives, PL3, in fluorotrichloromethane to (60)Co γ-rays at 77 K gave the corresponding cations, (1+), characterised by their e.s.r. spectra.The spectra establish that the SOMO for these cations is considerably localised on phosphorus, which contributes extensive atomic 3s and 3p character.The results confirm and extend previous studies using sulphuric acid matrices.The tendency for these cations to react with corresponding neutral molecules to give ?* dimer-cations PL3>(1+) is also confirmed. The structures of these species are discussed and compared with those of related radicals.
Hasegawa, Akinori,McConnachie, Glen D. G.,Symons, Martyn C. R.
p. 1005 - 1016
(2007/10/02)

Metallacarboranes in Catalysis. 3. Synthesis and Reactivity of exo-nido-Phosphinerhodacarboranes
The carbon-substituted closo-bis(triphenylphosphine)hydridorhodacarborane , the carbon-substituted exo-nido-bis(triphenylphosphine)rhodacarborane complexes , and the salt (1+)(1-) were prepared by the reaction of the carborane anions (1-) (Ia-e) with in benzene.Complexes IIa,c exhibited a closo-exo-nido equilibrium in solution.The exo-nido complexes can be regarded as being composed of an (1+) cation bound to a (1-) anion cage via two exo polyhedral three-center, two-electron interactions (Rh-H-B bridges) with terminal hydrogen atoms.The (1+) moiety can apparently rotate with respect to and, in some cases, migrate about the polyhedral surface of the cage.Complex IIA reacted with 2 equiv of PCy3 ( Cy = cyclohexyl) to generate the mixed phosphine exo-nido complex (IIIa).Reaction of the exo-nido-bis(triphenylphosphine)rhodacarboranes with good ? donors or CO displaced the rhodium from the carborane cage to give cationic species of the form (1+), (1+), (1+) (L = PPh3, S = solvent); (1+) (L = PEt3); (1+) (L-L = dppe); and (1+) (L-L-L = Ph2PCH2CH2P(Ph)CH2CH2PPh2 = triphos, L' = PPh3).The (1+) complexes (Va-e) reacted further to generate closo species of the general formula .The 3,1,2-isomer was obtained when R = R' = Me (VIIc), R, R' = μ-(CH2)3- (VIId), and R, R' = μ-(1',2'-CH2C6H4CH2-) (VIIa); but in the cases of R = Ph, R' = Me and R = 1'-(closo-1',2'-C2B10H11), R' = H, a polytopal rearrangement occurred, resulting in the formation of , R = Me, R' = Ph (VIb) and R = H, R' = 1'-(closo-1',2'-C2B10H11) (VIe).The complexes IIa-d and IIIa underwent oxidative addition of H2 to give dihydrido Rh(III) products in which the (1+) or (1+) fragment remains bonded to the carborane cage through two three-center, two-electron Rh-H-B interactions.Molecular structures of two representative exo-nido-rhodacarboranes (IIb and IIIa) along with that of closo-rhodacarborane (IIa) have been determined and are formally presented in the following paper of this series.
Long, Judith A.,Marder, Todd B.,Behnken, Paul E.,Hawthorne, M. Frederick
p. 2979 - 2989
(2007/10/02)

SOLVENT EFFECTS ON THE REACTION OF TRIETHYLPHOSPHINE WITH CARBON DISULPHIDE
Thermodynamic and kinetic parameters have been measured for the reaction of triethylphosphine with carbon disulphide in several non-aqueous solvents.The observed free energy, entropy, and enthalpy values are discussed in terms of solvation of the reactants, products, and transition state, using regression on solvent parameters.
Ibanez, W. Fernando,Santos, B. Jose G.
p. 1323 - 1326
(2007/10/02)

Deoxygenation and Desulfurization of Organic Compounds via Transition Metal Atom Cocondensation
Reactions resulting from the cocondensation of transition metal atoms with a variety of oxygen- and sulfur-containing organic compounds are surveyed.Alkenes are the major or exclusive volatile products when epoxides are reacted with Ti, V, Cr, Co, and Ni atoms. 2,6-Dimethylpyridine-N-oxide and dimethyl sulfoxide undergo deoxygenation upon cocondensation with chromium, but diisopropyl ether and decyl methyl ether do not.Dibenzyl ether yields bis(η6-dibenzyl ether)chromium(0) with Cr atoms, but dibenzyl sulfide undergoes desulfurization.Cyclohexanone and cycloheptanone afford low yields of reductive coupling and aldol products when cocondensed with Cr, Co, and Ni atoms.Nitro- and nitrosoarenes are deoxygenated to coupled azo and azoxy products with Cr atoms.Carbazole (3) is obtained from 2-nitrosobiphenyl, implicating nitrene or nitrenoid intermediates.Whereas isocyanides are not formed from isocyanates and metal atoms, they are produced when isothiocyanates are cocondensed with Cr and V atoms.
Togashi, Shigeo,Fulcher, John G.,Cho, Bong Rae,Hasegawa, Minoru,Gladysz, J.A.
p. 3044 - 3053
(2007/10/02)

NMR study (1H, 13C and 31P) of the nPX3-n compounds (X=Cl, C2H5; n=0,1,2,3)
1H, 13C and 31P NMR data of the compounds nPX3-n (X=Cl, C2H5; n=0,1,2,3) are reported.While the 1H and 13C resonances from the PEt moiety rather follow the electron-withdrawing effect of the -NEt substituent, 1H and 13C chemical shift data from the -NEt2 moiety reveal a quite important shift contribution originating from sterically induced polarization of the C-H bonds. 31P chemical shift data are interpreted in terms of inductive effects but the anomalous diamagnetic shift deviation from linearity for X=Cl suggests a minor contribution from multiple bonding.The general trend observed in the 31P-couplings is quite straightforward and can be qualitatively explained by Bent's rule.
Linthoudt, J. P. van,Berghe, E. V. van den,Kelen, G. P. van der
p. 315 - 320
(2007/10/02)

Selective formation of ethanol from methanol, hydrogen and carbon monoxide
A process for the selective formation of ethanol which comprises contacting methanol, hydrogen and carbon monoxide with a catalyst system comprising cobalt acetylacetonate, a tertiary organo Group V A compound of the periodic Table, a first promoter comprising an iodine compound and a second promoter comprising a ruthenium compound.
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(2008/06/13)

Oxidative addition production of trans-halo-2(1,3-alkadienyl)bis(triethylphosphine) complexes of nickel(II), palladium(II), and platinum(II)
The production of trans-halo-2(1,3-alkadienyl)bis(triethylphosphine) complexes of nickel(II), palladium(II), and platinum(II) by oxidative addition is disclosed.
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(2008/06/13)