The reaction of trihydrobistriphenylphosphine iridium IrH3(PPh3)2 with diazonium salts

The reaction of IrH₃(PPh₃)₂ with p-substituted aryldiazonium salts gives the compounds [IrH₂(NHNC₆H₄R)(PPh₃)₂]⁺BF₄^- at low temperature (-10°C) and the o-metalated complexes [I$\text{rH(NHN}$C₆H₃R)(PPh₃)₂]⁺BF₄^- (R  F, OCH₃) at 40–50°C. The reactions of the o-metalated complexes with CO, PPh₃, NaI and HCl have been studied.     

Allyldifluorophosphite-metal chemistry: Ru complexes of F2POC3H5 and the crystal structure of (Ph3P)2(F2POC3H5)Ru(CO)(Cl)H

With several chloro ruthenium phosphine complexes, allyldifluorophosphite, F₂POC₃H₅, displaces triphenylphosphine to form new compounds in which it acts as a phosphorus donor ligand. The new complexes [PPh₃]₂[F₂POC₃H₅]Ru[CO][Cl][H], I, and [(PPh₃)₂(F₂POC₃H₅)₂RuCl₂]_nII, hav characterized by chemical, spectroscopic, and, in the case of I, crystallographic means. This behaviour of F₂POC₃H₅ contrasts to its reactions with several platinum and palladium chloro complexes where it undergoes Arbuzov-type rearrangements.     

Cluster chemistry XXV *. Synthesis and structure of Ru4(μ4-η2, P-HCCC6H4PPh2)(CO)11·0.5CH2Cl2

The olefinic tertiary phospine complex Ru₃(CO)₁₀(μ-η², P-CH₂CHC₆H₄PPh₂) is converted to the title μ₄-alkyne-Ru₄ cluster at 135°C; the latter is also formed from H₂Ru₃(μ₃-η², P-HCCC₆H₄PPh₂)(CO)₈ and Ru₃(CO)₁₂. Crystals of the Ru₄ complex are monoclinic, space group P2₁, with a 8.700(3), b 17.611(3), c 11.926(2) Å, β 102.720(3)°, with Z = 2; 1702 data (I > 2.5 (σ)I) were refined to R = 0.026, R_w = 0.028. The molecule contains a distorted octahedral Ru₄C₂ core, one carbon of which is attached to an o-C₆H₄PPh₂ moiety coordinated via P to a wing-tip Ru of the Ru₄ butterfly.     

Efficient and mild method for preparation of allylic amines from aziridine-2-alcohols using PPh3/I2/imidazole

Allylic amines are synthesized in good to excellent yields by treatment of aziridine-2-alcohols with PPh₃/I₂/imidazole in THF as solvent under mild conditions.     

Four isomers from the oxidative addition of Me3SnH to Os(CO)2(PPh3)3 and the crystal structure of Os(SnMeI2)I(CO)2(PPh3)2, in which the pairs of CO and PPh3 ligands are mutually trans

Reaction between Os(CO)₂(PPh₃)₃ and Me₃SnH produces Os(SnMe₃)H(CO)₂(PPh₃)₂ (1). Multinuclear NMR studies of solutions of 1 reveal the presence of four geometrical isomers, the major one being that with mutually cis triphenylphosphine ligands and mutually trans CO ligands. Os(SnMe₃)H(CO)₂(PPh₃)₂ undergoes a redistribution reaction, at the trimethylstannyl ligand, when treated with Me₂SnCl₂ giving Os(SnMe₂Cl)H(CO)₂(PPh₃)₂ (2). Solutions of 2 again show the presence of four isomers but now the major isomer is that with mutually trans triphenylphosphine ligands and mutually cis CO ligands. The redistribution reaction of 1 with SnI₄ produces Os(SnMeI₂)H(CO)₂(PPh₃)₂ (3) which exists in solution as only one isomer, that with mutually trans triphenylphosphine ligands and mutually trans CO ligands. Treatment of 3 with I₂ cleaves the Os-H bond with retention of geometry giving Os(SnMeI₂)I(CO)₂(PPh₃)₂ (4). The crystal structure of 4 has been determined. No isomerization of the trans dicarbonyl complex 4 occurs when 4 is heated, instead there is a formal loss of “MeSnI” and formation of OsI₂(CO)₂(PPh₃)₂ (5).     

Thiocarbonyl complexes of ruthenium(II). Synthesis of RuCl2(CS)(H2O)(PPh3)2 and RuHCl(CS)(PPh3)3

A high-yield synthesis of trans-RuCl₂(CS)(H₂O)(PPh₃)₂ from RuCl₂(PPh₃)₃ and CS₂ is described. The coordinated water molecule is labile, and introduction of CNR (R  p-toyl or p-chlorophenyl) leads to yellow trans-RuCl₂(CS)(CNR)(PPh₃)₂, which isomerises thermally to colourless cis-RuCl₂(CS)(CNR)(PPh₃)₂. Reaction of AgClO₄ with cis-RuCl₂(CS)(CNR)(PPh₃)₂ gives [RuCl(CS)(CNR)(H₂O)(PPh₃)₂]⁺, from which [RuCl(CS)(CO)(CNR)(PPh₃)₂]⁺ and [RuCl(CS)(CNR)₂(PPh₃)₂]⁺ are derived. Reaction of trans-RuCl₂(CS)(H₂O)(PPh₃)₂ with sodium formate gives Ru(η²-O₂CH)Cl(CS)(PPh₃)₂, which undergoes decarboxylation in the presence of (PPh₃) to give RuHCl(CS)(PPh₃)₃. Ru(η²-O₂CH)H(CS)(PPh₃)₂ and Ru(η²-O₂CMe)-H(CS)(PPh₃)₂ are also described.     

Phenoxide-assisted P-C bond cleavage in PdCl2(PPh3)2 under very mild conditions

PdCl₂(PPh₃)₂ reacted with NaOAr (Ar = Ph, p-tolyl) at 0 °C to afford PdCl(Ph)(PPh₃)₂, instead of PdCl(OAr)(PPh₃)₂, in 12-16% isolated yields based on Pd. The structure was confirmed by NMR and X-ray crystallography. GC-MS analysis of the reaction solution revealed that OPPh₂(OAr), OPPh(OAr)₂, and OP(OAr)₃ are formed, while NMR studies indicated that PdCl(Ph)(PPh₃)₂ is produced when PdCl(OAr)(PPh₃)₂ decomposes. The reaction of PdCl₂(PPh₃)₂ with Bu₃Sn(OC₆H₄-p-OMe) also gave PdCl(Ph)(PPh₃)₂ in 8% isolated yield. These results suggest that PdCl(OAr)(PPh₃)₂ is highly labile and the aryloxy ligand exchanges with the phenyl groups in triphenylphosphine even under very mild conditions.     

Molybdenum and tungsten complexes of the neutral tripod ligands HC(pz)3 and MeC(CH2PPh2)3

Starting from [M(CO)₆], seven-coordinated complexes of tungsten and molybdenum containing the facially coordinating ligands HC(pz)₃ (1) and MeC(CH₂PPh₂)₃ (2) were obtained in a two-step reaction sequence. The complexes have a 4:3 piano stool geometry with almost perfect C_S symmetry in the crystal. In solution, they show the typical fluxional behavior for seven-coordinated complexes even at low temperature. Complete oxidative decarbonylation occurs when [HC(pz)₃Mo(CO)₃] (4) or [MeC(CH₂PPh₂)₃Mo(CO)₃] (6) are treated with an excess of I₂ or Br₂.     

The reactions of Ir(CO)Cl(PPh3)2 with HSnPh3

A reinvestigation of the reaction of Ir(CO)Cl(PPh₃)₂, 1 with HSnPh₃ has revealed that the oxidative-addition product Ir(CO)Cl(PPh₃)₂(H)(SnPh₃), 2 has the H and SnPh₃ ligands in cis-related coordination sites. Compound 2 reacts with a second equivalent of HSnPh₃ by a Cl for H ligand exchange to yield the new compound H₂Ir(CO)(SnPh₃)(PPh₃)₂, 3. Compound 3 contains two cis- related hydride ligands. Under an atmosphere of CO, 1 reacts with HSnPh₃ to replace the Cl ligand with SnPh₃ and one of the PPh₃ ligands with a CO ligand and also adds a second equivalent of CO to yield the 5-coordinate complex Ir(CO)₃(SnPh₃)(PPh₃), 4. Compound 4 reacts with HSnPh₃ by loss of CO and oxidative addition of the Sn-H bond to yield the 6-coordinate complex HIr(CO)₂(SnPh₃)₂(PPh₃), 5 that contains two trans-positioned SnPh₃ ligands.     

Synthesis and characterisation of HRuRh3(CO)12. Crystal structures of HRuRh3(CO)12, HRuRh3(CO)10(PPh3)2 and HRuCo3(CO)10(PPh3)2

A new ruthenium-rhodium mixed-metal cluster HRuRh₃(CO)₁₂ and its derivatives HRuRh₃(CO)₁₀(PPh₃)₂ and HRuCo₃(CO)₁₀(PPh₃)₂ have been synthesized and characterized. The following crystal and molecular structures are reported: HRuRh₃(CO)₁₂: monoclinic, space group P2₁/c, a 9.230(4), b 11.790(5), c 17.124(9) Å, β 91.29(4)°, Z = 4; HRuRh₃(CO)₁₀(PPh₃)₂·C₆H₁₄: triclinic, space group P$\text{1}$, a 11.777(2), b 14.079(2), c 17.010(2) Å, α 86.99(1), β 76.91(1), γ 72.49(1)°, Z = 2; HRuCo₃(CO)₁₀(PPh₃)₂·CH₂Cl₂: triclinic, space group P$\text{1}$, a 11.577(7), b 13.729(7), c 16.777(10) Å, α 81.39(4), β 77.84(5), γ 65.56°, Z = 2. The reaction between Rh(CO)₄^? and (Ru(CO)₃Cl₂)₂ tetrahydrofuran followed by acid treatment yields HRuRh₃(CO)₁₂ in high yield. Its structural analysis was complicated by a 80–20% packing disorder. More detailed structural data were obtained from the fully ordered structure of HRuRh₃(CO)₁₀(PPh₃)₂, which is closely related to HRuCo₃(CO)₁₀(PPh₃)₂ and HFeCo₃(CO)₁₀(PPh₃)₂. The phosphines are axially coordinated.     

Stereochemical nonrigidity of the square complex (PPh3)2Pt(HgGePh3)(GePh3)

³¹P, ¹⁹⁵Pt and ¹⁹⁹Hg NMR spectra of complex (PPh₃)₂Pt(HgGePh₃)(GePh₃) (I) have been studied. The spectra at temperatures below ?40°C prove that (I) is a cis-isomer with the square-planar coordination of the Pt atom. The reversibility of temperature dependences of spectra, insensitivity of line shape to the solvent, concentration and presence of free phosphine establish the fluxional behaviour of (I). The activation parameters of the intramolecular rearrangement which is realized, most probably, through a digonal twist, are: Δ^≠₂₉₈ = 51.5 ± 2.9 kJ/mol, ΔH^≠ = 59.3 ± 2.9 kJ/mol, ΔS^≠ = 26.2 ± 9.7 J/mol. K.     

The tris(triphenylphosphine)osmium zerovalent complexes Os(CO)2(PPh3)3, .Os(CO)(CNR)(PPh3)3, Os(CO)(CS)(PPh3)3, Os(CS)(cNR)(PPh3)3 and derived compounds

Detailed procedures for the syntheses of Os(CO)₂(PPh₃)₃, Os(CO)(CNR)-(PPh₃)₃ (R = p-tolyl), Os(CO)(CS)(PPh₃)₃ and Os(CS)(CNR)(PPh₃)₃, together with the derived complexes Os(CO)₂(CS)(PPh₃)₂, Os(CO)(CS)(CNR)(PPh₃)₂, Os(η²-C₂H₄)(CO)(CNR)(PPh₃)₂, Os(η²-C₂H₄)(CO)(CS)(PPh₃)₂, Os(η²CS₂)(CO)₂-(PPh₃)₂, Os(η²CS₂)(CO)(CS)(PPh₃)₂, Os(η²-CS₂)(CO)(CNR)(PPh₃)₂, Os(η²PhC₂Ph)(CO)₂(PPh₃)₂ and OsH(C2Ph)(CO)₂(PPh₃)₂ are described.     

Synthesis and molecular structure of [Au3Ru4(μ3-H)(CO)12(PPh3)3]

The title compound can be prepared in good yield by heating either [Ru₄(μ-H)₄(CO)₁₂] or [Au₂Ru₄(μ₃-H)₂(CO)₁₂(PPh₃)₂] with [AuMe(PPh₃)] in toluene. The related compound [Au₃Ru₄(μ₃-H)(μ-dppm)(CO)₁₂(PPh₃)] has also been prepared. Both trigoldtetraruthenium clusters undergo dynamic behaviour in solution, involving intramolecular rearrangement of the metal core, as revealed by variable temperature NMR studies. The crystal structure of [Au₃Ru₄(μ₃-H)(CO)₁₂(PPh₃)₃] has been established by an X-ray diffraction study. The metal atom core comprises a trigonal bipyramidal AuRu₄ unit with two AuRu₂ faces capped by gold atoms.     

Simple protocol for the synthesis of the asymmetric PCP pincer ligand [C6H4-1-(CH2PPh2)-3-(CH(CH3)PPh2)] and its Pd(II) derivative [PdCl{C6H3-2-(CH2PPh2)-6-(CH(CH3)PPh2)}]

The asymmetric PCP pincer ligand [C₆H₄-1-(CH₂PPh₂)-3-(CH(CH₃)PPh₂)] (4) has been synthesized in a facile manner in three simple steps in high yield. Metallation of PCP pincer ligand (4) with [Pd(COD)Cl₂] affords complex [PdCl{C₆H₃-2-(CH₂PPh₂)-6-(CH(CH₃)PPh₂)}] (7) in good yield.     

Kinetic investigations on interaction of carbon monoxide with RuIICl2(PPh3)3 in mixed aqueous medium

Kinetics, equilibrium and thermodynamics of interaction of CO with RuCl₂(PPh₃)₃ (1) have been investigated in 1:1(v/v) water — 1,4-dioxan mixture in which 1 dissociates to RuCl₂(PPh₃)₂ (1a), by losing a coordinated PPh₃. The kinetics of complexation of (1a) with CO to form RuCl₂(CO)(PPh₃)₂ (2) indicated first order dependence in [1a] and [CO]. The thermodynamic parameters for the formation of 2 were determined.This revised version was published online in December 2005 with corrections to the Cover Date.     

Formation and structural characterization of novel polynuclear palladium selenolato complexes [Pd3Se(SePh)3(PPh3)3]Cl and [Pd6Cl2Se4(SePh)2(PPh3)6]

In addition to well-known dinuclear phenylselenolato palladium complexes, the reaction of [PdCl₂(PPh₃)₂] and NaSePh affords small amounts of novel trinuclear and hexanuclear complexes [Pd₃Se(SePh)₃(PPh₃)₃]Cl (1) and [Pd₆Cl₂Se₄(SePh)₂(PPh₃)₆] (2). Complex 1 is triclinic, P1?, a=13.6310(2), b=16.2596(2), c=16.9899(3) Å, α=83.1738(5), β=78.9882(5), γ=78.7635(5)°. Complex 2 is monoclinic, C2/c, a=25.7165(9), b=17.6426(8), c=27.9151(14) Å, β=110.513(2)°. There are no structural forerunners for 1, but the hexanuclear complex 2 is isostructural with [Pd₆Cl₂Te₄(TeR)₂(PPh₃)₆] (R=Ph, C₄H₃S) that have been observed as one of the products in the oxidative addition of R₂Te₂ to [Pd(PPh₃)₄]. Mononuclear palladium complexes may play a significant role as building blocks in the formation of the polynuclear complexes.     

Synthesis of [TpRu(CO)(PPh3)]2(μ-CHCHCHCHC6H4CHCHCHCH) from Wittig reactions

Treatment of [Ru(CHCHCH₂PPh₃)X(CO)(PPh₃)₂]⁺ (X=Cl, Br) with KTp (Tp=hydridotris(pyrazolyl)borate) and NaBPh₄ produced [TpRu(CHCHCH₂PPh₃)(CO)(PPh₃)]BPh₄. Reaction of RuHCl(CO)(PPh₃)₃ with HCCCH(OEt)₂ produced Ru(CHCHCH(OEt)₂)Cl(CO)(PPh₃)₂, which reacted with KTp to give TpRu(CHCHCHO)(CO)(PPh₃). Treatment of [TpRu(CHCHCH₂PPh₃)(CO)(PPh₃)]BPh₄ with NaN(SiMe₃)₂ and benzaldehyde produced TpRu(CHCHCHCHPh)(CO)(PPh₃). The later complex was also produced when TpRu(CHCHCHO)(CO)(PPh₃) was treated with PhCH₂PPh₃Cl/NaN(SiMe₃)₂. The bimetallic complex [TpRu(CO)(PPh₃)]₂(μ-CHCHCHCHC₆H₄CHCHCHCH) was obtained from the reaction of [TpRu(CHCHCH₂PPh₃)(CO)(PPh₃)]BPh₄ with NaN(SiMe₃)₂ and terephthaldicarboxaldehyde.     

Propionyl complexes of ruthenium derived from the reaction of ethylene with RuHCl(CO)2(PPh3)2

RuHCl(CO)₂(PPh₃)₂ reacts with ethylene under mild conditions (25 psi, 80°C) to yield a propionyl derivative RuCl(C[O]C₂H₅)(CO)(PPh₃)₂ which is believed to be coordinatively unsaturated. Unlike the acetyl analogue, RuCl[C[O]C₂H₅(CO)-(PPh₃)₂ does not isomerize to RuCl(C₂H₅)(CO)₂(PPh₃)₂ in solution. Under one atmosphere of carbon monoxide, RuCl(C[O]C₂H₅(CO)(PPh₃)₂ exists in equilibrium with two species believed to be RuCl(C[O]C₂H₅)(CO)₂(PPh₃)₂ and [Ru(C[O]C₂H₅)(CO)₃(PPh₃)₂]Cl. RuCl(C[O]C₂H₅)(CO)(PPh₃)₂ reacts with CO/ AgClO₄ to give mer-[Ru(C[O]C₂H₅)(CO)₃(PPh₃)₂]ClO₄, p-tolylisocyanide (RNC) and NaClO₄ to give cis-[Ru(C[O]C₂H₅)(CO)(CNR)₂(PPh₃)₂ClO₄, and hydrochloric acid to yield the hydroxycarbene complex, RuCl₂(CO)(C[OH]C₂H₅)(PPh₃)₂.     

Synthesis,spectroscopic characterization,crystal and molecular structure of [ReOX2(bopyH)(PPh3)] complexes: DFT calculations for [ReOCl2(bopyH)(PPh3)]

The reactions of [ReOX₃(PPh₃)₂] (X = Cl, Br) with benzoylpyridine (bopy) have been examined and novel [ReOX₂(bopyH)(PPh₃)] oxocompounds have been obtained. The complexes were structurally and spectroscopically characterised. In the both structures two-electron reduced form of benzoylpyridine is coordinated to the central ion. The electronic structure of [ReOCl₂(bopyH)(PPh₃)] has been calculated with the density functional theory (DFT) method, and additional information about binding has been obtained by NBO analysis. The UV–Vis spectrum of the [ReOCl₂(bopyH)(PPh₃)] has been discussed on the basis of TDDFT calculations.     

On the catalytic duo PdCl2(PPh3)2/AuCl(PPh3) that cannot effect a Sonogashira-type reaction: a correction

In contrast to the observation made by the Laguna group, we report that the combination of PdCl₂(PPh₃)₂ and AuCl(PPh₃) makes a unique catalytic system that allows Sonogashira-type cross-coupling of both aryl and alkyl alkynes with aryl halides in excellent yields.