Synthesis and characterization of Rh3(μ-PPh2)3(CO)3(PPh3)2: a novel triangular rhodium cluster

Thermal decomposition of RhH(CO)(PPh₃)₃ (Ph = phenyl) in nonane at 120°C yielded a green solid in high yield. The complex was established as Rh₃(μ-PPh₂)₃(CO)₃(PPh₃)₂, (I), X-ray crystallography. I was found to be coordinately unsaturated in the solid state and in solution.     

Synthesis and molecular structure of [Rh3(μ-PPh2)3(CO)6(PPh2-H)], an unusual six-membered inorganic ring complex

Reaction of [{Rh(μ-Cl)(CO)₂}₂] with PPh₂H in CO-saturated ethanol yields [Rh₃(μ-PPh₂)₃ (CO)₆ (PPh₂H)], a red trinuclear cluster of rhodium containing a near-planar six-membered Rh₃P₃ ring; this compound reversibly undergoes elimination of CO and PPh₂H to afford [Rh₃(μ-PPh₂)₃(CO)₅].     

Photochemical reactions of (CO)2 (PPh3)MnC5H4Fe(CO)2C5H5 and (CO)2(PPh3)MnC5H4COFe(CO)2C5H5 with PPh3

Conclusions The photochemical reactions of (CO)₂(PPh₃)MnC₅H₄Fe(CO)₂C₅H₅ and (CO)₂(PPh₃)MnC₅H₄COFe(CO)₂C₅H₅ with PPh₃ gave the products of replacing the CO on the Fe atom by PPh₃: respectively (CO)₂(PPh₃)MnC₅H₄Fe (CO)(PPh₃)C₅H₅ and (CO)₂(PPh₃)MnC₅H₄COFe(CO)(PPh₃)C₅H₅.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2813–2815, December, 1977.     

Synthesis of RuH2(CO)(PPh3)3 in a CO2 and H2 atmosphere

Summary RuH₂(CO)(PPh₃)₃ was prepared in a CO₂ and H₂ atmosphere from RuCl₃ and PPh₃ in the presence of alcohol and Et₃N. Introduction of CO into the system lead to the formation of other complexes e.g. Ru(CO)₃-(PPh₃)₂. Addition of alkali in place of Et₃N resulted in a decrease in the RuH₂(CO)(PPh₃)₃ yield.Author to whom all correspondence should be directed.     

Reaction of tetrakis (trifluoromethyl)allene with anions [CpMo(CO)2PPh3]- and [CpW(CO)2PPh3]

Conclusions The-dienyl complexes are formed when tetrakis (trifluoromethyl)allene is reacted with dicarbonyltriphenylphosphine--cyclopentadienylmolybdate and dicarbonyltriphenylphosphine--cyclopentadienyltungstate.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 681–683, March, 1978.     

Addition of C2(CO2Me)2 to trans-MeIr(CO)(PPh3)2. Formation and isomerization of MeIr(CO)(PPh3)2[C2(CO2Me)2], and crystal structure of the thermodynamic isomer

The reaction of C₂(CO₂Me)₂ with trans-MeIr(CO)(PPh₃)₂ leads to a kinetic isomer which has been characterized by ¹H and ³¹P NMR and infrared spectra and to a thermodynamic isomer which has been characterized by ¹H and ³¹P NMR, infrared, microanalysis and X-ray crystallography. The isomerization occurs readily in solution at room temperature; somewhat more slowly at −20°C. The thermodynamically stable isomer of MeIr(CO)(PPh₃)₂[C₂(CO₂Me)₂] crystallizes in the centrosymmetric monoclinic space group P2₁/c with a 14.847(2), b 16.648(2), c 15.656(3) Å, β 90.595(14)°, V 3869.7(11) ų and Z = 4. Single-crystal X-ray diffraction data were collected with a Syntex P2₁ automated diffractometer (Mo-K_α radiation, 2θ 5–40°) and the structure was solved and refined to R_F 8.6% for all 3631 independent data (R_F 4.0% for those 2318 data with |F_o| > 6σ(|F_o|)). The Ir^I center has a trigonal-bipyramidal environment with the methyl ligand and one PPh₃ ligand occupying axial sites (Ir-Me 2.193(14), Ir-P(1) 2.425(4) Å). The C₂(CO₂Me)₂ ligand is π-bonded to the iridium atom and lies with its triple bond parallel to the equatorial coordination plane; the equatorial ligands are completed by the second PPh₃ ligand (Ir-P(2) 2.402(3) Å) and a CO ligand (Ir-CO 1.812(15) Å).     

The reaction of Ru3(CO)12 with HC9PPh2)3. Characterisation of Ru3(CO)9[HC(PPh2)3], and crystal and molecular structure of Ru3(CO)9[HC(PPh2)(PhPC6H4PPh)]·CHCl3

Reaction of Ru₃(CO)₁₂ with HC(PPh₂)₃ leads to a variety of products, two of which have been characterised. One is the symmetrically capped product Ru₃(CO)₉[HC(PPh₂)₃], which was characterised spectroscopically. The second product was characterised crystallographically as Ru₃(CO)₉[HC(PPh₂)-(PhPC₆H₄PPh)]-CHCl₃.     

Synthesis of a μ4-PPh mixed metal cluster: the x-ray structures of [Ru3Rh2(CO)13(PEt3)(μ4-PPh)] and [Ru3Au(μ2-H)(CO)9(PMe2Ph)(μ3-PPh)]

The synthesis of a (μ₄-PPh) and some related (μ₃-PPh) mixed metal clusters containing ruthenium is described together with the X-ray structures of [Ru₃Rh₂(CO)₁₃(PEt₃)(μ₄-PPh)] and [Ru₃Au(μ₂-H)(CO)₉(PMe₂Ph)(μ₃-PPh)].     

Synthese und Molekülstruktur von [Li(THF)4][{(CO)4Mo}2(μ-PPh2)(μ-PPh2PPh2)]: Die erste Verbindung mit einem 1,3-Dimetalla-cyclopentaphosphan-Gerüst

Synthesis and Molecular Structure of [Li(THF)₄][{(CO)₄Mo}₂(μ-PPh₂)(μ-PPh₂PPh₂)]: The First Compound with an 1,3-Dimetalla-cyclopentaphosphane Ring [Mo(CO)₄(NBD)] (NBD = norbornadiene) reacts with LiPPh₂ and PPh₂PPh₂ in THF at –80 °C to give [Li(THF)₄][{(CO)₄Mo}₂(μ-PPh₂)(μ-PPh₂PPh₂)] ( 1 ). 1 exhibits an A₂X coupling pattern in the ³¹P NMR spectrum. A crystal structure determination showed the presence of bridging phosphanido (PPh₂) and diphosphane ligands (PPh₂PPh₂). The central Mo₂P₃ five-membered ring adopts a half-chair conformation and thus resembles an inorganic cyclopentane.     

Low oxidation state ruthenium chemistry : IV. The reactions of M(CO)2(PPh3)3 complexes (M = Fe,Ru) and the hydrogenation and isomerization of alkenes catalyzed by RuL(CO)2(PPh3)2 (L = H2, PPh3)

The complexes M(CO)₂(PPh₃)₃ (I, M = Fe; II, M = Ru) readily react with H₂ at room temperature and atmospheric pressure to give cis-M(H)₂(CO)₂(PPh₃)₂ (III, M = Fe;IV,M = Ru). I reacts with O₂ to give an unstable compound in solution, in a type of reaction known to occur with II which leads to cis-Ru(O₂)(CO)₂(PPh₃)₂(V). Even compound IV reacts with O₂ to give V with displacement of H₂; this reaction has been shown to be reversible and this is the first case where the displacement of H₂ by O₂ and that of O₂ by H₂ at a metal center has been observed. III and IV are reduced to M(CO)₃(PPh₃)₂ by CO with displacement of H₂; Ru(CO)₃- (PPh₃)₂ is also formed by treatment of IV with CO₂, but under higher pressure. Compounds II and IV react with CH₂CHCN to give Ru(CH₂CHCN)(CO)₂- (PPh₃)₂(VI) which reacts with H₂ to reform the hydride IV.cis-Ru(H)₂(CO)₂(PPh₃)₂(IV) has been studied as catalyst in the hydrogenation and isomerization of a series of monoenes and dienes. The catalysts are poisoned by the presence of free triphenylphosphine. On the other hand the ready exchange of H₂ and O₂ on the “Ru(CO)₂(PPh₃)₂” moiety makes IV a catalyst not irreversibly poisoned by the presence of air. It has been found that even Ru(CO)₂(PPh₃)₃(II) acts as a catalyst for the isomerization of hex-1-ene at room temperature under an inert atmosphere.