Synthesis and X-Ray Crystal Structures of Fe2Ru(CO)12−n (CNBu t ) n and FeRu2(CO)12−n (CNBu t ) n (n=1, 2)

The clusters Fe₂Ru(CO)_12–n (CNBu ^t ) _n (3, n=1; 4, n=2), FeRu₂(CO)_12–n (CNBu ^t ) _n (5, n=1, 6, n=2) and FeRu₂(CO)₁₁(CNCy) (5a) have been prepared by direct substitution from the parent carbonyl precursors Fe₂Ru(CO)₁₂ (1) and FeRu₂(CO)₁₂ (2). All compounds have been characterized spectroscopically and clusters 3, 4, 5, and 6 by single crystal X-ray determinations. In all cases, the isonitrile ligands adopt axial or pseudo-axial positions on a ruthenium atom. The structures of 3–5 are very similar to their parent clusters, but the extent of metal framework disorder is significantly less. Cluster 6 adopts the same C _2v Fe₃(CO)₁₂ type structure as 4, and thus differs markedly from the parent compound 2, which has a D ₃ structure .     

Synthesis and Structure of New Cobalt–Carbonyl Complexes Containing Tellurium Atoms

Co₂(CO)₈ and Te₂O react to form the well known Co₄(CO)₁₀Te₂, Co₄(CO)₁₁Te₂ complexes and the two new cluster complexes CCo₆(CO)₁₂Te₂(1), and CCo₆(CO)₁₀Te₂(Te₃) (2). The structures of 1 and 2 were determined by X-ray analysis, together with the triphenylphosphine derivative of 1, CCo₆(CO)₁₁(PPh₃)Te₂(3), which was analyzed to clarify the disordered structure of the parent compound. Complex 1 is formed by a prismatic cluster of cobalt atoms with a carbon embedded in the cage; two tellurium atoms cap the triangular faces of the prism and each cobalt atom links two terminal carbonyl groups. The complex 2 has a similar prismatic cage CCo₆; two ₄-Te atoms cap two rectangular faces of the prism, while other two Te atoms bridge two edges of the triangular faces and are linked each other through a third Te atom. Electron counting gives for complex 2 92 electrons: the presence of two long Co–Co distances suggests that the two excess electrons are located on Co–Co antibonding orbitals. Crystal data for 1, space group C2/c, a = 12.845(2) Å, b = 13.449(2) Å, c = 13.246(2) Å, = 91.95(2)°, Z = 4, R = 0.097 for 2555 reflections; for 2, space group Pnna, a = 17.219(5) Å, b= 14.969(6) Å, c = 9.178(4) Å, Z = 4,R = 0.037 for 3103 reflections; for 3, space group P2₁/c, a = 9.288(2) Å, b = 14.920(6) Å, c = 26.300(9) Å, = 99.99(2)°, Z = 4, R = 0.037 for 4300 reflections. The vibrational analysis of the complex 1 was performed and most of the (CO), (₆C–Co), (Co–Co) and (Co–Co) modes were assigned. The (Co–Te) modes were interpreted on the basis of the intermolecular coupling, due to the close contact between neighboring clusters in one distinct direction in the crystal.     

Preparation and reactivity of metal-containing monomers

Mono- and disubstituted cluster metal-containing monomers were obtained under mild conditions on interaction of Rh₆(CO)₁₆ with 4-vinylpyridine (4-ViPy) in the presence of N-trimethylaminoxide. These products were characterized by IR and¹H NMR spectroscopy and by elemental and X-ray analyses. Rh₆(CO)₁₅(4-ViPy) was found to be an octahedral cluster with eleven terminal and four ₃-bridging carbonyl ligands. 4-ViPy is linked with the Rh(3) atom through the N atom and occupies the coordination site of the twelfth CO terminal ligand. The mean value of the Rh-Rh bond length is 2.762 Å. The unsaturated ligand has little or no effect on the geometry of the starting cluster and its double bond retains the ability to undergo addition reactions.For part 28, seeRuss. Chem. Bull., 1993, 453.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 975–979, May, 1993.     

Organometallic chemistry and homogeneous catalysis of Rh and Rh-Co mixed metal carbonyl clusters

The reactions of hydrosilane and/or alkyne as well as isonitriles with rhodium and rhodium cobalt mixed metal carbonyl clusters, e.g., Rh₄(CO)₁₂ and Co₂Rh₂(CO)₁₂, are studied. Novel mixed metal complexes, e.g., CoRh(CO)₅ (HCCBu ⁿ ), (R₃Si)₂Rh(CO) _n Co(CO)₄, Rh(R–NC)₄Co(CO)₄, Co₂Rh₂(CO)₁₀(HCCR), and Co₂Rh₂(CO)₉(HCCBu ⁿ ), are synthesized and identified. The catalytic activities of these rhodium and rhodium-cobalt mixed metal complexes are examined in hydrosilyation, silylformylation, and novel silylcarbocyclization reactions. Possible mechanisms for these reactions are proposed and discussed.     

Interaction of iron carbonyls with Lewis bases

The interaction of iron carbonyls Fe _n (CO) _m (wheren = 1,m = 5;n = 2,m = 9;n = 3,m = 12) with anionic Lewis bases (H^–, F^–, Cl^–, Br^– , I^–, CN^–, SCN^–, N₃ ^–, MeSO₃ ^–, MeCO₂ ^–, CF₃CO₂ ^–, S₂ ^–, CO₃ ^2–, and SO₄ ^2–) passes through two-stage redox-disproportionation. The first stage is the formation of an iron carbonyl-base complex, [Fe _n (CO) _m–1C(O)L]^–, and the second is a single-electron reduction of this complex by another molecule of the initial iron carbonyl, giving rise to Fe(l) and Fe(–l) derivatives.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 248–249, January, 1996.     

Polar bonds in π-complexes. Preparation and crystal structures of cyclopentadienylcarbonyl iron(II) and ruthenium(II) benzoates andp-fluorobenzoates

Complexes of Fe(II) and Ru(II) of the general formula Cp(OC)₂MOC(O)C₆H₄X-p, where M=Fe, X=H, F (1, 2) or M=Ru, X=H, F (3, 4) have been prepared by reactingp-XC₆H₄COOAg with [CpFe(CO)₂]₂ or CpRu(CO)₂I. The crystal structures of complexes1–3 have been determined using X-ray diffraction. Compounds1 and3 are isomorphous. The COO group in1–3 is coordinated as a monodentate ligand. As the latter and the CO ligands are electronically non-equivalent, the coordination of the Cp ligand to the metal is slightly asymmetric.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 395–399, February, 1993.     

Synthesis of hydrocarbons from CO and H2 on SiO2 supported iron-cobalt clusters

Bimetallic catalysts (Fe+Co)/SiO₂ were prepared by impregnation of SiO₂ with solutions of carbonyl clusters [FeCo₃(CO)₁₂][(C₂H₅)₄N], [Fe₃Co(CO)₁₃][(C₂H₅)₄N], HFeCo₃(CO)₁₂, [Fe₅CoC(CO)₁₆][(C₂H₅)₄N], and Co₂(CO)₈, Fe(CO)₅. At 20 °C, no reaction occurs between the compounds supported and the surface of the support. The stability of the supported clusters to thermodecarboxylation in a hydrogen atmosphere depends on their composition and is the highest for the catalyst [FeCo₃(CO)₁₂]^–/SiO₂. The catalytic properties of supported clusters in CO hydrogenation are mostly determined by the preactivation technique. The properties of Fe-Co catalysts which were pretreated at high temperatures, are in general similar to those of standard metal catalysts. Product distribution for the same samples prepared without preactivation does not fit the Schulz-Flory equation. The catalyst HFeCo₃(CO)₁₂/SiO₂ favors the formation ofC ₁–C₁₁ hydrocarbons in the temperature range of 468–473 K; the catalyst [Fe₃Co(CO)₁₃]^–/SiO₂ gives ethylene in the temperature range of 453–473 K.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1079–1085, June, 1993.     

POSSIBLE HYDRIDE AND METHIDE TRANSFER REACTIONS: REACTIONS OF Fe(CO)4R−(R = H,CH3) AND W(CO)5R− (R = H,CH3, Cl,Br, I) WITH METAL CARBONYL CATIONS

Abstract

Reactions of metal carbonyl cations (M(CO)₆ ⁺, M = Mn, Re) with hydride-, methide- or halide-containing metal carbonyl anions (Fe(CO)₄R^?, R = H, Me; W(CO)₅R^?, R = H, Me, Cl, Br, I) produce products that indicate several mechanisms are operative. Reactions of the halo-tungsten complexes produce neutral, solvated tungsten complexes, W(CO)₅(CH₃CN) and W(CO)₄(CH₃CN)₂ and M(CO)₅X in a reaction that appears to be initiated by decomposition of W(CO)₅X^?. In contrast, the tungsten hydride and methide complexes react, predominantly, by transfer of the hydride or methide to a carbonyl of the cation at a much faster rate. The iron hydride and methide complexes react by iron-based nucleophilicity involving a two-electron process.     

Kinetics and catalysis by NaY entrapped Pt carbonyl clusters in the CO+NO reaction

[Pt₁₂(CO)₂₄]^2–/NaY and [Pt₉(CO)₁₈]^2–/NaY exhibited much higher activities in the CO+NO reaction at 473 K compared with Pt/Al₂O₃. Kinetic study andin-situ FTIR results suggest that NO adsorption is the rate-limiting step in the CO+NO reaction on intrazeolite Pt carbonyl clusters.     

Isomere η2-Acyl- und σ-Alkyl(carbonyl)-Komplexe von Molybdän und Wolfram. Eine Studie zum Bildungs-mechanismus,zur Isomerisierungsgeschwindigkeit und zur Steuerung der Gleichgewichtslage

η²-Acyl and σ-Alkyl(carbonyl) Coordination in Molybdenum and Tungsten Complexes: Synthesis and Studies of the Isomerization Equilibria and Kinetics The anionic molybdenum and tungsten complexes [L_RM(CO)₃]^? (L_R^? = [(C₅H₅)Co{P(O)R₂}₃]^?, R = OCH₃, OC₂H₅, O-i-C₃H₇; M = Mo, W) have been alkylated with the iodides R′ I, R′ = CH₃, C₂H₅, i-C₃H₇, and CH₂C₆H₅. The reactivity pattern of the alkylation is in accord with a S_N2 mechanism. Depending on M, R′, reaction temperature, and time the η-alkyl (carbonyl) compounds [L_RM(CO)₃R′] and/or the isomeric η²-acyl compounds [L_RM(CO)₂(η²-COR′)] can be obtained. 8 new σ-alkyl(carbonyl) compounds and 15 new η²-acyl compounds have been isolated and characterized. The ¹H NMR and the IR spectra give conclusive evidence that the σ-alkyl(carbonyl) compounds [L_RM(CO)₃R′] are formed as the primary products of the alkylation and that they isomerize partly or completely to give the η²-acyl compounds [L_RM(CO)₂(η²-COR′)]. The position of the equilibrium σ-alkyl(carbonyl)/η²-acyl is controlled by the steric demands of the groups R′ and the ligands L_R^?. The molybdenum compounds isomerize much more readily than the tungsten compounds. The rate constants of the isomerization processes [L_RMo(CO)₃CH₃] → [L_RMo(CO)₂(η²-COCH₃)], R = OCH₃, OC₂H₅, and O-i-C₃H₇, measured at 305 K in acetone-d₆, are 6–8 x 10^?3 s^?1.     

Rhodium(1) carbonyl complexes with alkyl sulphoxides and sulphides

Summary Rhodium(I) carbonyl complexes, namely Rh(CO)X(R₂SO)₂ (R = Me, n-Pr or n-Bu) and Rh(CO)X(R₂S)₂ (R = Me, Et or i-Pr) and X = CI or Br, have been prepared and characterized. The compounds Rh(CO)X[P(OPh)₃]₂ X = Cl or Br, have also been isolated. In the R₂SO and R₂S complexes, the carbonyl stretching frequencies occur atca. 2020–2025 cm^–1 andca. 1950–1980 cm^–1 respectively. In the R₂SO ligand containing complexes v(S-O) occurs atca. 1100–1125 cm^–1 indicative of metal-sulphur coordination. In presence of HBF₄, the addition of an excess of Me₂SO to (OC)₂Rh(-Cl)₂Rh(CO)₂ gives [Rh(Me₂SO)₆]³⁺ in which the central metal atom undergoes spontaneous oxidation from Rh¹(d⁸) to Rh^III(d⁶). The complexes have been characterized additionally by u.v.vis. spectra, conductivity measurements and by elemental analyses.     

The synthesis and reactivity of the heptanuclear dianion [Os7(CO)20]2− including the synthesis and structural characterizations of the compounds [Os7(CO)20(AuPEt)3 2] and [Os8(CO)20(η6-C6H6]

Reduction of the heptaosmium cluster [Os₇(CO)₂₁] With [Et₄N][NH₄) gives the cluster dianion [Os₇(CO)₂₀]^2–,1, in high yield. The reaction of the dianion with [AuPR ₃Cl] (R=Et or Ph) in the presence of TlPF₆ forms [Os₇((CO)₂₀(AuPR ₃)₂] [R=Et (2a);R = Ph(2b)] in 80% yield, while the corresponding reaction with (Os(C₆H₆)(CH₃CN)₃]²⁺ gives [Os₈(CO)₂₀ ( ⁶-C₆H₆)] (3) in reasonable yield (ca. 30%). The dianion,1, and the clusters2 and3 have been fully characterized by bout spectroscopic and crystallographic methods. The crystal structure of the [Ph₄P]⁺ salt of1 shows that the metals in the anion adopt a capped octahedral geometry, with all twenty carbonyl ligands in terminal sites. The metal core geometry in2a is best described as a tricapped octahedron, and is based on the structure of the dianion1 with two adjacent octahedral faces capped by the Au atoms of the two AuPEt₃ groups. In a similar fashion, the geometry of3 is related to that of1 with the addition of an Os(C₆H₆) unit capped to a triangular face, to give a bicapped octahedral framework.     

Synthesis and structure of complexes formed in the reaction between dicobalt octacarbonyl and tetramethyl-biphosphine disulfide

Co₂(CO)₈ and Me₂P(S)P(S)Me₂ react to form the two cluster complexes: Co₄(CO)₉S(PMe₂)₂) (1) and Co₃(CO)₇S(SPMe₂) (2). The strucure of1 and of the disubstituted triphenyl phosphine derivative of2. Co₃(CO)₅(PPh₃)₂S (SPMe₃) (2a) were determined. Compound1 contains a quasi-planar rhomboidal Co₄ cluster formed by two Co₃ isosceles triangles sharing a Co-Co edge. One triangle is capped by a sulfur atom, the other triangle has two edge-bridging PMe₂ moieties. Electron counting gives 64 electrons corresponding to a planar system; the distribution of long Co-Co distances, in particular in the triangle bearing PMe₂ bridges, suggests that the excess electrons are located on Co-Co antibonding ortibals. Compound2a contains a Co₃S cluster with one side bridged by a SPMe₂ unit forming a four-membered Co₂SP ring. The substitution of two CO groups with two PPh₃ causes a large deformation of the cluster Co-Co bondscis to these two phosphorus atoms. Crystal data for1, space group P1,a = 9.728(2) Å,b = 10.288(2) Å,c = 11.860(3) Å, = 86.41(2)°, = 76.20(2)°, = 80.37(5)°,Z = 2, 5300 reflections,R = 0.0398; for2a, space group P1,a = 9.78(3) Å,b = 13.05(4) Å,c = 18.28(6) Å, = 93.23(3)°, = 99.17(2)°, = 97.26(6)°,Z = 2, 2976 reflections,R = 0.0579.     

Ruthenium Tris(pyrazolyl)borate Complexes. Part 20 [1]. Synthesis,Characterization, and Reactivity of Neutral Trispyrazolylborate Ruthenium Vinylidene Complexes

Summary. The reaction of RuTp(COD)Cl (1) with PPh₂Prⁱ and terminal alkynes HCCR (R=C₆H₅, C₄H₃S, C₆H₄OMe, Fc, C₆H₄–Fc, C₆H₉) affords the neutral vinylidene complexes RuTp(PPh₂Prⁱ) (Cl)(=C=CHR) (2a–2f) in high yields. These complexes do not react with MeOH to give methoxy carbene complexes of the type RuTp(PPh₂Prⁱ)(Cl)(=C(OMe)CH₂R), but react with oxygen to yield the CO complex RuTp(PPh₂R)(Cl)(CO) (3). The structures of 2b, 2f, and 3 have been determined by X-ray crystallography.     

Sb–C Bond Cleavage Reaction on a Triruthenium Cluster and the Formation of a Bridging Phenylacyl Unit

Syntheses and single crystal X-ray structures of an open triruthenium acyl carbonyl cluster [(C₆H₅)₂SbRu₃(COC₆H₅)(CO)₁₀] (1) and a simple triruthenium Ru₃(CO)₉[(C₆H₅)₂PCH₂P(C₆H₅)₂]Sb(C₆H₅)₃ (2) are reported. Formation of compound (1) at room temperature from [Ru₃(CO)₁₂] and [Sb(C₆H₅)₃] is unique, a similar reaction with Ru₃(CO)₁₀[(C₆H₅)₂PCH₂P(C₆H₅)₂] under identical conditions results in compound (2), with Sb(C₆H₅)₃ occupying an equatorial site. IR, ¹H, ¹³C NMR spectra of the compounds are reported. The X-ray crystal structure of (1) consist of 2 crystallography distinct molecules and shows Ru–Sb distances in the range: 2.6361(6)–2.6273(7) Å and Ru–Ru distances in the range: 2.8236(7)–2.9855(7) Å. Ru–O distances in the bridging carbonyl are: 2.137(4), 2.158(4) Å. The Sb–Ru–Ru angles in the two molecules of the asymmetric unit are in the range of 73.78(2)–77.52° indicating the puckered nature. Compound (2) has bond parameters comparable to those of Ru₃(CO)₁₀[(C₆H₅)₂PCH₂P(C₆H₅)₂]. The present study shows for the first time that the cleaving of Sb–C bond at room temperature is possible under non-ionic conditions, though there have been many instances of P–C and As–C bond cleavages reported previously.     

Ruthenium Tris(pyrazolyl)borate Complexes. Part 20 [1]. Synthesis, Characterization, and Reactivity of Neutral Trispyrazolylborate Ruthenium Vinylidene Complexes

The reaction of RuTp(COD)Cl (1) with PPh₂Prⁱ and terminal alkynes HCCR (R=C₆H₅, C₄H₃S, C₆H₄OMe, Fc, C₆H₄–Fc, C₆H₉) affords the neutral vinylidene complexes RuTp(PPh₂Prⁱ) (Cl)(=C=CHR) (2a–2f) in high yields. These complexes do not react with MeOH to give methoxy carbene complexes of the type RuTp(PPh₂Prⁱ)(Cl)(=C(OMe)CH₂R), but react with oxygen to yield the CO complex RuTp(PPh₂R)(Cl)(CO) (3). The structures of 2b, 2f, and 3 have been determined by X-ray crystallography.     

Multinuclear NMR studies on substituted derivatives of Rh6(CO)16 in solution

Multinuclear NMR data (¹³C, ³¹P, ¹³C–{³¹P}, ¹³C–{¹⁰³Rh} and ³¹P–{¹⁰³Rh}) for a series of mono- and di-substituted derivatives of Rh₆(CO)₁₆ containing neutral two electron donor ligands [Rh₆(CO)₁₅L, (L=NCMe, py, cyclooctene, PPh₃, P(OPh)₃,1/2(μ₂,η¹:η¹-dppe)); Rh₆(CO)₁₄(LL), (LL=cis-CH₂=CMe-CMe=CH₂, dppm, dppe, (P(OPh)₃)₂)] are reported; these data show that the solid state structure is maintained in solution. Detailed assignments of the ¹³CO NMR spectra of Rh₆(CO)₁₅(PPh₃) and Rh₆(CO)₁₄(dppm) clusters have been made on the basis ¹³C–{¹⁰³Rh} double resonance measurements and the specific stereochemical features of the observed long range couplings in these clusters have been studied. The stereochemical dependence of ³J(P–C) for terminal carbonyl ligands is discussed and the values of ³J(P–C) are found to be mainly dependent on the bond angles in the P–Rh–Rh–C fragment; these data enable the fine structure of the complex multiplets in the ¹³C–{¹H} and ³¹P–{¹H} NMR spectra of Rh₆(CO)₁₄ (dppm) to be simulated. Variable temperature ¹³C–{¹H} NMR measurements on Rh₆(CO)₁₅(PPh₃) reveal the carbonyl ligands in this complex to be fluxional. The fluxional process involves exchange of all the CO ligands except the two terminal CO's associated with the rhodium trans to the substituted rhodium and can be explained by a simple oscillation of the PPh₃ on the substituted rhodium atom aided by concomitant exchange of the unique terminal CO on this rhodium with adjacent μ₃-CO's.     

Cyclopentadienyl diruthenium metal carbonyl complexes bearing pendant thienyl ligands

Abstract  

Reactions of the thienyl side chain functionalized cyclopentadienyls (C₄H₃S)C(R₁R₂)C₅H₅[R₁, R₂ = CH₃ (1); R₁, R₂ = (CH₂)₅ (2); R₁, R₂ = C₂H₅ (3)] with Ru₃(CO)₁₂ in refluxing xylene gave the corresponding cyclopentadienyl diruthenium carbonyl complexes [(η ⁵-C₄H₃S)CR₁R₂(C₅H₄)Ru(CO)₂]₂ (R₁, R₂ = CH₃ (4); R₁, R₂ = (CH₂)₅ (5); R₁, R₂ = C₂H₅ (6)), which were characterized by elemental analysis, IR and ¹H NMR spectra. The molecular structures of 4, 5 and 6 were determined by single crystal X-ray diffraction.     

Steric and Electronic Influences in Os3(CO)11(PR3) Structures

The structures of Os₃(CO)₁₁(PR₃) with R=F, OPh, Et, p-C₆H₄Me, o-C₆H₄Me, p-C₆H₄(CF₃) and C₆H₁₁, and with PR₃=P(OCH₂)₃CMe have been determined. The Os–Os bond lengths in these compounds are compared to the Os–Os lengths for the other structures of Os₃(CO)₁₁(PR₃) clusters reported in the literature. In most cases, the Os–Os bond length remote from the P ligand [range, 2.8666(4)–2.9044(4) Å] and that in the pseudo-trans position [range, 2.8712(5)–2.900(1) Å] show little variation as the steric and electronic properties of the P ligand are varied. The Os–Os length cis to PR₃ shows more variation [range, 2.879(1)–2.9429(4) Å] and is sensitive to both the size and the -donor/-acceptor properties of the PR₃ ligand: larger or better donor PR₃ ligands cause an increase in the Os–Os bond length. The Os–P distances [range, 2.15(2)–2.478(1) Å] show a similar dependence on the steric and electronic properties of the PR₃ ligand.     

Chemistry of iridium carbonyl cluster complexes. Synthesis,characterization and solid state structure of the phosphido carbonyl cluster [Ir6(CO)12(μ-CO)2(μ-PPh2)−

The phosphido-bridged cluster [Ir₆(CO)₁₄ PPh2]^– has been obtained by reaction of [Ir₆(CO)₁₅]^2– with PHPh₂, in the presence of ferrocenium cation, followed by deprotonation. The anion was isolated as a salt of [N(PPh₃)₂]⁺ or K⁺ and its structure was determined by single crystal X-ray data analysis. The salt [N(PPh₃)₂][Ir₆(CO)₁₄PPh₂] crystallizes in the triclinic space group P witha = 11.835(1) Å,b = 15.007(1) Å,c = 18.766(2)_ Å; = 78.779(7)°, = 87.260(8)°, = 75.794(6)°,V = 3169.3(7) Å,Z = 2. The structure was solved by Direct Methods and Difference Fourier techniques and refined down toR andR _w values of 0.034 and 0.036, respectively, for 8003 observed reflections havingl > 3(I). The octahedral anion, of idealized C₂ symmetry, possesses two distance Ir-P = 2.284 Å, formally acting as a three electron donor. Average bond distances (Å) and angles (degrees) are: Ir-Ir = 2.776, Ir-C _t = 1.87, Ir-C _b = 2.05, C _t -O _t = 1.14, C _b -O_b= 1.17, Ir-P-Ir = 74.3°, Ir-C _t -O _t = 177°, Ir-C _b -O _b = 138°, Ir-C _b -Ir = 84° (t = terminal,b = bridging).