15243-33-1Relevant articles and documents
Synthesis and structural characterisation of ruthenium and osmium carbonyl clusters containing organomercurials
Kong, Fung-Sze,Wong, Wing-Tak
, p. 2497 - 2510 (1999)
Reaction of the activated cluster [Os3(CO)10(NCMe)2] with [PhHgS(C5H4N)] afforded two new Os-Hg clusters cis-[Os(CO)4{Os3(CO)10(μ-η 2-SC5H4N)(μ-Hg)}2] 1 and [{Os3(CO)10(μ-η2-SC5H 4N)}2(μ4-Hg)] 2 in 25 and 30% yields, respectively. Cluster 1 consists of two {Os3(CO)10(μ-η2-SC5H 4N)(μ-Hg)} subunits bonded to a central Os(CO)4 moiety in a cis configuration. Cluster 2 comprises two skewed Os-Hg metal butterflies sharing a common wingtip Hg atom. Treatment of the same organomercurial with [Ru3(CO)10(NCMe)2] produced the cluster compound cis-[Ru(CO)4{Ru3(CO)9(μ-η 3-SC5H4N)(μ-Hg)}2] 3 (48%). This has a metal skeleton similar to that of 2 with the {S(C5H4N)} ligand moiety bonding to the ruthenium atoms in a μ-η3 fashion. Treatment of [Os3(CO)10(NCMe)2] with [PhHg(mbt)] (Hmbt = 2-mercaptobenzothiazole) afforded [{Os3(CO)10(μ-η2-mbt)} 2(μ4-Hg)] 4 (35%) and [Os3(CO)10(μ-η2-mbt)(μ-η 2-Hg(mbt)] 5 (20%). Cluster 4 is very similar to 2, but the S(C5H4N) ligand is replaced by the mbt ligand, while 5 consists of an Os3 triangle having one edge spanned by both [μ-η2-mbt] and [μ-η2-Hg(mbt)] moieties. The reaction of [Os5C(CO)15] and [Ru3(CO)12] with another class of organomercurial (diphenylthiocarbazono)phenylmercury reagent [PhHgL′] [L′ = SC(N=NPh)(=NNHPh)] containing a N=N functionality under thermal conditions produced [{Os5C(CO)14(μ-η2-SPh)} 2(μ4-Hg)] 6 (26%) and [{Os5C(CO)14(μ-η2-L′)} 2(μ4-Hg)] 7 (34%) and [Ru2(CO)4Ph{μ-η2-C(O)Ph}(μ 2-S)(μ-η2-L′)] 8 (15%), [Ru2(CO)4(C(O)Ph) {μ-η2-C(O)Ph}(μ2-S)(μ-η 2-L′)] 9 (15%) and [{Ru(CO)2Ph}2(μ-η2-L′)] 10 (45%), respectively. In clusters 6 and 7, two {Os5C(CO)14} subunits linked by a common wingtip mercury atom, are bonded with both μ-η2-SPh in 6 and μ-η2-L′ in 7. However, in the case of complexes 8, 9 and 10, only binuclear ruthenium carbonyl complexes formed instead of the expected formation of mixed-metal clusters. Complexes 1-10 result from the cleavage of both Hg-C and Hg-S bonds in the parent organomercury species. All these complexes have been fully characterized by both spectroscopic and crystallographic techniques.
Organosulphur-Transition-metal Chemistry. Part 5. Face Bonding of Cycloheptatrienyl and Cyclo-octatetraene Ligands in Sulphur-Ruthenium Clusters: Crystal and Molecular Structure of t)(μ3-(η7-C7H7))>
Cresswell, T. Anthony,Howard, Judith A. K.,Kennedy, Fiona G.,Knox, Selby A. R.,Wadepohl, Hubert
, p. 2220 - 2229 (1981)
The sulphur-ruthenium cluster complex t)> reacts with cycloheptatriene in boiling heptane to give t)(μ3-(η7-C7H7))> and t)(μ-(η7-C7H7))>.The former contains a facebridging cycloheptatrienyl ligand, established through an X-ray diffraction study.Crystals are monoclinic, space group C2/c, with eight molecules in a unit cell of dimensions a=14.875(6), b=8.902(6), c=30.977(2) Angstroem, and β=94.785(4) deg.The structure has been solved by conventional techniques, revealing the ruthenium atoms to be present in isosceles triangular units disordered in ca. 2:1 ratio via a 60 deg rotation in the ruthenium plane.Refinement was by least squares for 3860 data to R 0.041.The ruthenium triangle is bridged on one side by a μ3-SBut ligand and on the other by a face-bonded C7H7 ring which is planar and lies parallel to the face at a distance of 2.07 Angstroem.The hydrogens of the C7H7 ligand are inclined away from the metal triangle as a result of ?-orbital reorientation.The ruthenium-carbon (ring) distances are compatible with bonding of the C7H7 ligand in η2,η2,η3 fashion to the metal triangle, each atom of which bears two terminal carbonyl groups, but n.m.r. spectra show that the ring rotates freely relative to the face in solution.The high-fild 13C n.m.r. shift (38.7 p.p.m.) for the μ3-(η7-C7H7) ligand is characteristic, comparing with 61.0 p.p.m. for similarly fluxional μ-(η7-C7H7) in t)(μ-(η7-C7H7))>.Treating t)(μ3-(η7-(C7H7))> with CO results in cluster fragmentation to yield t)(μ-(η7-C7H7))>, a reaction attributed to the ability of both SBut and C7H7 ligands to vary their mode of co-ordination.Reactions of t)> with cyclo-octatetraene, cyclo-octatriene, and cyclopentadiene also effect cluster breakdown, forming t)(μ-(η7-C8H9))> or t)(η-C5H5)2>.The sulphur-ruthenium cluster in is less easily destroyed.The reaction with cyclo-octatetrane provides 8-C8H8))>, containing rare face-bonded fluxional C8H8, while with cycloheptatriene the complexes 5-C7H9)(μ3-(η7-C7H7))>, 5-C7H9)(μ3-(η7-C7H7))>, and 7-C7H7))2> are obtained, partly characterised using the 13C n.m.r. criterion of the C7H7 bonding mode.
(13)C NMR study of reorientational dynamics in Ru3(Co)9(μ(3)-Co)(μ(3)-NPh). Relaxation time analysis in the non-motional narrowing regime
Wang, D.,Shen, H.,Richmond, M. G.,Schwartz, M.
, p. 1 - 6 (1995)
The NMR (13)C spin-lattice relaxation times of the phenyl group and equatorial carbonyl carbons in Ru3(CO)9(μ(3)-CO)(μ(3)-NPh) were measured as a function of temperature and resonance frequency in the solvent methylene chloride, and at several temperatures in chloroform. Phenyl T(1)s were used to calculate the diffusion coefficients characterizing molecular tumbling, D(.perp.), and spinning of the phenyl group, D(s); carbonyl relaxation times yielded the parallel diffusion coefficient, D(.paral.). Values of D(.perp.) calculated using the standard motional narrowing assumption were incorrectly observed to be frequency dependent, and inmarked error (by as much as a factor of two) from results obtained usin g the non-motionally narrowed equations. The spinning diffusion coefficients, D(s), were an order of magnitude greater than either D(.perp.) or D(.paral.), but somewhat lower than the rate of the equivalent rotation of free benzene in the same solvents, indicating the existence of a barrier to internal rotation of the phenyl group. Fenske-Hall and extended Hueckel calculations revealed that the barrier arises primarily from steric interactions between the ortho protons of the phenyl group and the carbon atom of the equatorial carbonyls.
The Reduction of (μ2-NO) in 2-NO)> to (μ3-NH) and (μ2-NH2) by Molecular Hydrogen
Johnson, Brian F. G.,Lewis, Jack,Mace, Julian M.
, p. 186 - 188 (1984)
- reacts with NOBF4 in moist MeCN to generate HRu3(CO)10NO, HRu3(CO)10NH2, and HRu4N(CO)12; the same products, together with H2Ru3(CO)9NH and H4Ru4(CO)12, are observed in the direct hydrogenation of HRu3(CO)10NO.
PROTONATION OF (μ-H)3Ru(μ3-CR)(CO)9. EVIDENCE FOR THE FORMATION OF AN AGOSTIC METAL-HYDROGEN-CARBON BOND
Bower, David K.,Keister, Jerome B.
, p. C33 - C36 (1986)
Protonation of (μ-H)3(μ3-CR)(CO)9 (M = Ru, R = Et or M = Os, R = Me) by dissolution in HSO3CF3 yields H3M3(HCR((CO)9+, containing a M-H-C bridge.The products were characterized by 1H and 13C NMR spectroscopy.Decompositions of other protoned methylidyne clusters form CH3R and a variety of metal-containing products.
The Chemical Activation of Iron, Ruthenium, and Osmium Carbonyl Cluster Anion-susing Oxidative Addition
Drake, Simon R.,Johnson, Brian F. G.,Lewis, Jack
, p. 1033 - 1035 (1988)
The chemical activation of iron, ruthenium, and osmium carbonyl cluster anions has been achived by investigating their oxidative electrochemistry and then matching the observed electrochemical oxidation potential with chemical reagents, by the use of oxidative addition in the presence of the required ligand; the dianionic clusters (2-), Ru3(CO)11>(2-), (2-), (2-), (2-), and (2-) have been found to react with multi-electron donor ligands in the presence of a suitable oxidant.
Improved Synthesis of the Hexanuclear Clusters (2-), (1-), and H2Ru6(CO)18. The X-Ray Analysis of (1-), a Polynuclear Carbonyl containing an Interstitial Hydrogen Ligand
Eady, Colin R.,Jackson, Peter F.,Johnson, Brian F. G.,Lewis, Jack,Malatesta, Maria Carlotta,et al.
, p. 383 - 392 (1980)
The X-ray analyses of two crystalline modifications, (I) and (II), of are reported, together with improved synthetic routes to this and the related clusters (2-) and H2Ru6(CO)18.Crystals of (I) are triclinic, space group P1-, with a=18.083(4), b=19.101(4), c=19.238(5) Angstroem, α=117.70(4), β=78.13(2), γ=97.05(2) deg, and Z=4.Crystals of (II) are monoclinic, space group P21/n, with a=33.82(8) b=52.55(10), c=9.832(2) Angstroem, β=92.66(2) deg, and Z=12.Least square refinement using diffractometer data (Mo-Kα) has given an R of 0.0681 for 9165 reflections for (I) and an R of 0.23 (Ru only) for 1485 reflections for (II).The unit cell in (I) contains two independent molecules of (1-), cluster (1) which is ordered and cluster (2) which is disordered between two sites (2A) and (2B) that are related by a non-crystallographic two-fold axis.The combined evidence of the X-ray analyses, 1H n.m.r. studies, i.r. spectra, and variable-temperature 13C n.m.r. is only consistent with the hydrogen ligand lying inside the Ru6 octahedron.
Novel polymeric carbonylhaloruthenium(I) polyanions: Rational design and self-reorganization in the presence of CO2 and H2O
Maurette, Luc,Donnadieu, Bruno,Lavigne, Guy
, p. 3707 - 3710 (1999)
We just need to mix [Ru(CO)3Cl2(thf)] with methanolic NEt4OH - nature will do the rest: The unsaturated fragments thus generated spontaneously polymerize with production of CO2 and H2O, which combine
Ferrari, Rosa P.,Vaglio, Gian A.,Valle, Mario
, (1978)
Dombek, B. Duane,Harrison, Arnold M.
, p. 2485 - 2486 (1983)
ROLE OF THE CATION IN THE REACTION OF Ci(CO)4- WITH RuCl3*xH2O. SYNTHESIS AND MOLECULAR STRUCTURE OF THE RUTHENIUM CLUSTER 2
Braunstein, Pierre,Rose, Jacky,Dusausoy, Yves,Mangeot, Jean-Paul
, p. 125 - 134 (1983)
Reaction of with RuCl3 * xH2O (4/1 ratio) in THF affords Ru3(CO)12, , and 2.The latter has been fully characterized by an X-ray structural analysis.These results are compared
Dimethyl sulfide substituted mixed-metal clusters. Synthesis, structure, and characterization of HRuCo3(CO)11(SMe2) and [HRuRh3(CO)9]2[SMe2]3
Rossi,Pursiainen,Ahlgren,Pakkanen
, p. 475 - 479 (1990)
Ligand substitution reactions of dimethyl sulfide with mixed-metal clusters are described. The clusters HRuCo3(CO)11(SMe2) (1) and [HRuRh3(CO)9]2[SMe2]3 (2) have been prepared by reactions of SMe2 with the neutral parent clusters. Their crystal structures have been established. Dimethyl sulfide coordinates terminally as a two-electron donor on basal cobalt in 1 and as a bridging four-electron donor causing unusual dimerization of clusters in 2. The carbonyl arrangement of the parent clusters was not changed during the ligand substitution, and hydride ligands bridge the three basal metals in both compounds.
New insight into a convenient base-promoted synthesis of Ru3(CO)12
Faure, Matthieu,Saccavini, Catherine,Lavigne, Guy
, p. 1578 - 1579 (2003)
The addition of two equivalents of KOH per Ru under 1 atm CO at 75°C to a mixture of [Ru(CO)2Cl2]n and [Ru-(CO)3Cl2]2 generated in situ by carbonylation of 5 grams of RuCl3·3H2O in 2-ethoxyethanol, triggers a reaction cascade producing Ru3(CO)12 in yields exceeding 90% within 45 minutes.
Cluster chemistry. 27. The synthesis and structural characterization of three mixed gold-cobalt-ruthenium carbonyl clusters Ph3PAuCoRu3(CO)13, (Ph3PAu)2CoRu3(H)(CO)12, and (Ph3PAu)3CoRu3(CO)12
Bruce, Michael I.,Nicholson, Brian K.
, p. 101 - 108 (1984)
A unique series of mixed gold-cobalt-ruthenium carbonyl clusters has been prepared and structurally characterized. Reaction of [(Ph3PAu)3O]BF4 with HCoRu3(CO)13 gives the three clusters Ph3PAu-CoRu3(CO)13 (1), (Ph3PAu)2CoRu3(H)(CO)12 (2), and (Ph3PAu)3CoRu3(CO)12 (3). An alternative specific route to 3 is via [(Ph3PAu)3O]BF4 and [CoRu3(CO)13] , while Ph3PAuCl and [CoRu3(CO)13]- give exclusively 1. For 1 [C31H15O13AuCoPRu3, a = 9.345 (3) ?, b = 14.217 (4) ?, c = 14.721 (3) ?, α = 114.83 (2)°, β = 93.16 (2)° γ = 92.44°, triclinic, P1, Z = 2] a trigonal-bipyramidal core is found, with the Ph3PAu group triply bridging a CoRu2 triangle. For 2 [C48H31Au2CoO12P2Ru 3·0.5CH2Cl2, a = 35.173 (9) ?, b = 13.548 (9) ?, c = 23.193 (4) ?, β = 102.27 (2)°, monoclinic, C2/c, Z = 8] a capped trigonal-bipyramid core exists with the second Ph3PAu group capping an AuRu2 face of 1 and the hydride ligand bridging an Ru-Ru bond. The structures are rationalized in terms of the maximum number of face-sharing tetrahedra; the isolobality of H and Ph3PAu is not valid in the context of polygold clusters.
METAL CLUSTERS IN CATALYSIS. THE REACTIVITY OF ALKYNE- AND VINYLIDENE-SUBSTITUTED HOMO- AND HETERO-METALLIC CLUSTERS TOWARDS MOLECULAR HYDROGEN IN HOMOGENEOUS CONDITIONS
Castiglioni, Mario,Giordano, Roberto,Sappa, Enrico
, p. 217 - 234 (1983)
The reactivity of alkyne- and vinylidene-substituted clusters towards molecular hydrogen in homogeneous conditions has been studied by means of GC and GC/MS techniques.The reactivity of the homo- and hetero-metallic cluster frames (containing nickel and one of the iron triad metals) is discussed, as well as that of the coordinated ligands.Under hydrogen the cluster cores are modified, sometimes as a part of a catalytic cycle.The products obtainable from the coordinated small molecules seem to depend mainly on the overall electronic situation of the clusters or on the C-C distances in the alkynes, and to a lesser extent on the number of coordinating metal centres.In some instances it was observed that when both free alkynes and substituted clusters were present, only the coordinated alkynes were hydrogenated.
The use of photogenerated intermediates in the study of cluster build-up reactions: The generation of Ru6C(CO)17 from Ru3(CO)12
Leadbeater, Nicholas E.
, p. 250 - 252 (1998)
The use of photochemistry in the study of cluster build-up reactions involving transition-metal carbonyl complexes has been illustrated by an investigation into the generation of the hexanuclear carbido cluster Ru6C(CO)17 from the tr
Tri- and tetranuclear mixed-metal clusters containing alkyne ligands: Synthesis and structure of [Ru3Ir(CO)11(RCCR')]-, Rru2Ir(CO)9(RCCR')]-, and [HRu2Ir(CO)9(RCCR')]
Ferrand, Vincent,Suess-Fink, Georg,Neels, Antonia,Stoeckli-Evans, Helen
, p. 853 - 862 (1999)
The tetrahedral cluster anion [Ru3Ir(CO)13]- (1) reacts with internal alkynes RC≡CR' to afford the alkyne derivatives [Ru3Ir(CO)11(RCCR')]- (2: R = R' = Ph; 3: R = R' = Et; 4: R = Ph; R' = Me; 5: R = R' = Me) which have a butterfly arrangement of the Ru3Ir skeleton in which the alkyne is coordinated in a μ4-η2 fashion. Under CO pressure they undergo fragmentation to give the trinuclear cluster anions [Ru2Ir(CO)9(RCCR')]- (6: R = R' = Ph; 7: R = R' = Et; 8: R = Ph; R' = Me; 9: R = R' = Me), in which the alkyne ligand is coordinated in a μ3-η2 parallel fashion. Protonation of these trinuclear anions leads to the formation of the corresponding neutral hydrido clusters [HRu2Ir(CO)9(RC≡CR')] (10: R = R' = Ph; 11: R = R' = Et; 12: R = Ph; R' = Me; 13: R = R' = Me). The protonation of the butterfly anions 2 and 3, however, gives rise to the formation of the neutral tetrahedral clusters [HRu3Ir(CO)11(RCCR')] (14: R = R' = Ph and 15: R = R' = Et), respectively. The analogous clusters [HRu3Ir(CO)11(PhCCCH3)] (16) and [HRu3Ir(CO)11(CH3CCCH3)] (17) are only accessible from the reaction of the neutral cluster [HRu3Ir(CO)13] with the corresponding alkynes. The complexes 2, 4, 5, 6, 10, 12 and 15 are characterised by X-ray structure analysis.
The synthesis of heteronuclear clusters containing cyclopentadienyl- or pentamethylcyclopentadienyliridium and ruthenium or osmium
Srinivasan, Padmamalini,Leong, Weng Kee
, p. 403 - 412 (2006)
The reaction of Cp*Ir(CO)2 or CpIr(CO)2 with Ru3(CO)12 under a hydrogen atmosphere afforded the heterometallic clusters Cp*IrRu3(μ-H)2(CO) 10 and CpIrRu3(μ-H)2(CO)10, respectively, in moderate yields. In the former reaction, the tetrahydrido cluster Cp*IrRu3(μ-H)4(CO)9 was also formed in trace amounts, although this cluster can be obtained in high yields by the hydrogenation of Cp*IrRu3(μ-H)2(CO) 10; the Cp analogue was not obtainable. The reaction of Os 3(μ-H)2(CO)10 with Cp*Ir(CO) 2 afforded the osmium analogue Cp*IrOs3(μ-H) 2(CO)10 in 70% yield, along with a trace amount of the pentanuclear cluster Cp*IrOs4(μ-H)2(CO) 13. Hydrogenation of Cp*IrOs3(μ-H) 2(CO)10 afforded Cp*IrOs3(μ-H) 4(CO)9 in excellent yield. The reaction of Cp*Ir(CO)2 with Os3(CO)10(CH 3CN)2 afforded the known trinuclear cluster Cp*IrOs2(CO)9 and the novel cluster Cp*IrOs3(CO)11. Solution-state NMR studies show that the hydrides in the iridium-ruthenium clusters are highly fluxional even at low temperatures while those in the iridium-osmium clusters are less so.
Formation of H2Ru6(CO)17 from H2Ru6(CO)18 an improved synthesis of HRu6(CO)17 B
McCarthy, Deborah A.,Bauer, Jeanette Krause,Hong, Fung-E,Oh, Jung Ran,Deng, Haibin,Liu, Jianping,Shore, Sheldon G.
, p. 309 - 314 (1998)
Spontaneous decarbonylation of the octahedral cluster H2Ru6(CO)18 produces the bicapped tetrahedral cluster H2Ru6(CO)17. The clusters H2Ru6(CO)18 and H2R6(CO)17 have strikingly similar IR and 1 H NMR spectra. In appearance they are indistinguishable; both are deep purple in color. The decarbonylation reaction is partially reversible under low pressures of CO. Reaction of H2Ru6(CO)17 with BH3S(CH3)2 provides an improved synthesis of HRu6(CO)17B, an octahedral cluster with a boron atom at the center of the Ru6 core. HRu6(CO)17B reacts with excess CO at high pressures to produce HRu4(CO)12BH2 and ruthenaboride clusters with pentanuclear metal cores that are proposed to be HRu5(CO)15B and HRu5(CO)16B.
Synthesis and Structural Characterisation of the Hexanuclear, Bimetallic, Ladder-like Cluster HRu5Cu(CO)18PPh3
Evans, John,Street, Andrew C.,Webster, Michael
, p. 637 - 638 (1987)
The bimetallic cluster HRu5Cu(CO)18PPh3 has been prepared by the reaction of CO with H3Ru4(CO)12CuPPh3, characterised by X-ray crystal structure analysis, and shown to contain a 'ladder-like' arrangement of Ru5Cu based on triangular units.
Ligand substitutions in Ru-Pt clusters: Isolation of compounds with unusual geometries
Hermans, Sophie,Khimyak, Tetyana,Feeder, Neil,Teat, Simon J.,Johnson, Brian F.G.
, p. 672 - 684 (2003)
Ligand substitution reactions of the COD (1,5-cyclooctadiene) ligand for CO or phosphines in the clusters [Ru5C(CO)14Pt(COD)] (1) and [Ru6C(CO)16Pt(COD)] (2) were investigated. Reactions with carbon monoxide gave selectively [Ru5CPt(CO)16] (3) from 1, but led to loss of either a ruthenium or the Pt(COD) unit from the Ru6Pt cluster (2). Substitution of the COD ligand by PPh3 in 1 gave [Ru5C(CO)14Pt(PPh3)2] (8) selectively, while with dppm the main product of the reaction was [Ru5C(CO)14Pt(μ-dppm)] (10). On the other hand, the reactions involving [Ru6C(CO)16Pt(COD)] (2) and phosphines led mainly to extrusion of the Pt(COD) fragment and formation of Ru-only derivatives. More precisely, with triphenylphosphine, the two clusters [Ru6C(CO)16PPh3] (16) and [Ru6C(CO)15(PPh3)2] (18) were obtained from 2, while with dppm, the compounds [Ru6C(CO)15(dppm)] (15) and [Ru6C(CO)13(dppm)2] (19) were formed. In the latter case, two additional products of increased nuclearity were isolated: [Ru6C(CO)15Pt2(dppm)] (20) and [Ru6C(CO)16Pt3(dppm)2] (21). All the compounds described were characterised by spectroscopic methods and the structures of the new species were determined by X-ray crystallography.
Reactivity of the 1-azavinylidene cluster [Ru3(μ-H)(μ-N=CPh2)(CO)10] with hydrogen, tertiary silanes and tertiary stannanes
Bois, Claudette,Cabeza, Javier A.,Franco, R. Jesus,Riera, Victor,Saborit, Enrique
, p. 201 - 207 (1998)
The reactivity of the 1-azavinylidene cluster [Ru3(μ-H)(μ-N=CPh2)(CO)10] (1) with hydrogen, tertiary silanes and tertiary stannanes has been investigated. The reaction of 1 with hydrogen (1 atm, 110°C) gives [Ru4/sub
Au, Yat-Kun,Cheung, Kung-Kai,Wong, Wing-Tak
, (1995)
Bruce, M. I.,Stone, F. G. A.
, (1966)
Reproducible high-yield syntheses of [Ru3(CO)12], [H4Ru4(CO)12], and [Ru6C(CO)16]2- by a convenient two-step methodology involving controlled reduction in ethylene glycol of RuCl3·nH2O
Lucenti, Elena,Cariati, Elena,Dragonetti, Claudia,Roberto, Dominique
, p. 44 - 47 (2003)
Ru3CO12 [H4Ru4(CO)12], and [Ru6C(CO)16]2- have been synthesized in reproducible high yields and under mild conditions (1 atm) by a two-step methodology involving (i) first carbonylation of RuCl3·nH2O dissolved in ethylene glycol to give a mixture of tri- and di-carbonyl ruthenium(II) species, probably of the kind [Ru(CO)3Cl2(ethylene glycol)] and [Ru(CO)2Cl2(ethylene glycol)x ] (x = 1, 2), and (ii) addition of specific amounts of alkali carbonates and further reductive carbonylation to give the desired ruthenium carbonyl cluster. The selectivity of the second step is controlled by the: (i) nature and quantity of the alkali carbonate (Na2CO3 or K2CO3); (ii) gas-phase composition (CO or CO+H2); (iii) temperature.
Synthesis of Indoles by Reductive Cyclization of Nitro Compounds Using Formate Esters as CO Surrogates
Ahmed Fouad, Manar,Ferretti, Francesco,Formenti, Dario,Milani, Fabio,Ragaini, Fabio
supporting information, p. 4876 - 4894 (2021/09/20)
Alkyl and aryl formate esters were evaluated as CO sources in the Pd- and Pd/Ru-catalyzed reductive cyclization of 2-nitrostyrenes to give indoles. Whereas the use of alkyl formates requires the presence of a ruthenium catalyst such as Ru3(CO)12, the reaction with phenyl formate can be performed by using a Pd/phenanthroline complex alone. Phenyl formate was found to be the most effective CO source and the desired products were obtained in excellent yields, often higher than those previously reported using pressurized CO. The reaction tolerates many functional groups, including sensitive ones like a free aldehydic group or a pendant pyrrole. Detailed experiments and kinetic studies allow to conclude that the activation of phenyl formate is base-catalyzed and that the metal doesn't play a role in the decarbonylation step. The reactions can be performed in a single thick-walled glass tube with as little as 0.2 mol-% palladium catalyst and even on a 2 g scale. The same protocol can be extended to other nitro compounds, affording different heterocycles.
Water-Soluble Ruthenium(II) Carbonyls with 1,3,5-Triaza-7-phosphoadamantane
Battistin, Federica,Balducci, Gabriele,Milani, Barbara,Alessio, Enzo
, p. 6991 - 7005 (2018/06/22)
As a continuation of our strategy for preparing new Ru(II) precursors with improved water solubility through the introduction of highly water-soluble 1,3,5-triaza-7-phosphoadamantane (PTA) supporting ligands in the coordination sphere, in this work, we address the largely unexplored preparation of Ru(II)-PTA carbonyls. Two complementary synthetic approaches were used: (1) the treatment of a series of neutral Ru(II)-CO-dmso compounds of general formula RuCl2(CO)n(dmso)4-n (n = 1-3, 1-5) with PTA; (2) the reaction of Ru(II)-PTA complexes with CO. Through the first approach, we obtained and fully characterized seven novel neutral compounds bearing from one to three PTA ligands per Ru atom, namely, the four monocarbonyls, cis,cis,trans-RuCl2(CO)(dmso-S)(PTA)2 (6), trans-RuCl2(CO)(PTA)3 (7), cis,mer-RuCl2(CO)(PTA)3 (8), and trans,trans,trans-RuCl2(CO)(OH2)(PTA)2 (10), and the three dicarbonyls, trans,trans,trans-RuCl2(CO)2(PTA)2 (11), [RuCl2(CO)2(PTA)]2 (12), and cis,cis,trans-RuCl2(CO)2(PTA)2 (13). The less stable, and thus more elusive, species fac-RuCl2(CO)(PTA)3 (9) and cis,cis,cis-RuCl2(CO)2(PTA)2 (14) were also unambiguously identified but could not be obtained in pure form and fully characterized. The complementary synthetic approach, that involved the treatment of the trans- and cis-RuCl2(PTA)4 (15, 16) isomers with CO, afforded only one new Ru(II)-PTA carbonyl, the cationic species cis-[RuCl(CO)(PTA)4]Cl (17). In general, the choice of the solvent was very relevant for obtaining the products with high yield and purity. We were unable to isolate Ru(II)-PTA compounds with more than two carbonyls. The thermodynamically preferred species have CO trans to Cl and two mutually trans PTAs, and only in the dinuclear compound 12 there is a single PTA per Ru atom. Compounds 7 and 17 feature the unprecedented trans-{Ru(CO)(PTA)} fragment. The X-ray structures of cis,cis,cis-RuCl2(CO)2(dmso)2 (3), 6-8, 10, 11, 13, and 17 are also reported. All compounds are new, are air-stable, and show a good solubility in water (S from 10 to 165 g·L-1) and, most often, also in chloroform.