33635-52-8Relevant academic research and scientific papers
In Situ FTIR and NMR Spectroscopic Investigations on Ruthenium-Based Catalysts for Alkene Hydroformylation
Kubis, Christoph,Profir, Irina,Fleischer, Ivana,Baumann, Wolfgang,Selent, Detlef,Fischer, Christine,Spannenberg, Anke,Ludwig, Ralf,Hess, Dieter,Franke, Robert,B?rner, Armin
supporting information, p. 2746 - 2757 (2016/02/27)
Homogeneous ruthenium complexes modified by imidazole-substituted monophosphines as catalysts for various highly efficient hydroformylation reactions were characterized by in situ IR spectroscopy under reaction conditions and NMR spectroscopy. A proper protocol for the preformation reaction from [Ru3(CO)12] is decisive to prevent the formation of inactive ligand-modified polynuclear complexes. During catalysis, ligand-modified mononuclear ruthenium(0) carbonyls were detected as resting states. Changes in the ligand structure have a crucial impact on the coordination behavior of the ligand and consequently on the catalytic performance. The substitution of CO by a nitrogen atom of the imidazolyl moiety in the ligand is not a general feature, but it takes place when structural prerequisites of the ligand are fulfilled.
Acrylic acid derivatives of group 8 metal carbonyls: A structural and kinetic study
Li, Bo,Kyran, Samuel J.,Yeung, Andrew D.,Bengali, Ashfaq A.,Darensbourg, Donald J.
, p. 5438 - 5447 (2013/06/26)
The synthesis, spectroscopic, and X-ray structural studies of acrylic acid complexes of iron and ruthenium tetracarbonyls are reported. In addition, the deprotonated η2-olefin bound acrylic acid derivative of iron as well as its alkylated species were fully characterized by X-ray crystallography. Kinetic data were determined for the replacement of acrylic acid, acrylate, and methylacrylate for the group 8 metal carbonyls by triphenylphosphine. These processes were found to be first-order in the concentration of metal complex with the rates for dissociative loss of the olefinic ligands from ruthenium being much faster than their iron analogues. However, the ruthenium derivatives afforded formation of primarily mono-phosphine metal tetracarbonyls, whereas the iron complexes led largely to trans-di-phosphine tricarbonyls. This difference in behavior was ascribed to a more stable spin crossover species 3Fe(CO)4 which undergoes rapid CO loss to afford the bis phosphine derivative. The activation enthalpies for dissociative loss of the deprotonated η2-bound acrylic acid ligand were found to be larger than their corresponding values in the protonated derivatives. For example, for dissociative loss of the protonated and deprotonated acrylic acid derivatives of iron(0) the ΔH? values determined were 28.0 ± 1.2 and 34.1 ± 1.5 kcal·mol-1, respectively. Density functional theory (DFT) computations of the bond dissociation energies (BDEs) in these acrylic acids and closely related complexes were in good agreement with enthalpies of activation for these ligand substitution reactions, supportive of a dissociative mechanism for olefin displacement. Processes related to catalytic production of acrylic acid from CO2 and ethylene are considered.
Heterobinuclear and heterotrinuclear metal μ-allenyl complexes containing platinum and one or both of iron and ruthenium. Synthesis of higher nuclearity metal complexes from mononuclear metal η1-propargyls and η1-allenyls and from binuclear metal μ-η1:η2α,β-allenyls
Willis, Richard R.,Shuchart, Chris E.,Wojcicki, Andrew,Rheingold, Arnold L.,Haggerty, Brian S.
, p. 3179 - 3191 (2008/10/08)
The reactions of Cp(CO)2MCH2C≡CPh with Pt(PPh3)4 or Pt(PPh3)2C2H4 in THF at reflux and of Cp(CO)2MCH=C=CH2 with Pt(PPh3)2C2H4 in THF or hexane at -78 °C to ambient temperature afforded the heterobinuclear metal μ-allenyl complexes (PPh3)2Pt(μ-η1:η2 α,β-C(Ph)=C=CH2)M(CO)Cp (M = Ru, R = Ph (1a); M = Fe, R = Ph (2a); M = Ru, R = H (1b); M = Fe, R = H (2b)). The products reacted with Ru3(CO)12 or Fe2(CO)9 (Ru, Fe = M′) in THF at room temperature to yield open heterotrinuclear metal μ-allenyl complexes (PPh3)-(CO)Pt(μ3-η1:η 2:η2-C(R)=C=CH2)M′(CO) 3M(CO)Cp (M′ = M = Ru, R = H (4); M′ - Ru, M = Fe, R = H (5); M′ = Fe, M = Ru, R = Ph (6a); M′ = Fe, M = Ru, R = H (6b); M′ = M = Fe, R = H (7)), as well as M′(CO)4PPh3. The reaction of 1a with Fe2(CO)9 also afforded the CO-for-PPh3 substitution product (PPh3)(CO)Pt(μ-η1:η2 α,β-C(Ph)=C=CH2)Ru(CO)Cp (3). Treatment of the μ-allenylcarbonyl (CO)3Fe(μ-η1:η3-η 2-C(O)C(Ph)=C=CH2)Ru(CO)Cp with Pt(PPh3)2C2H4 in THF at 0 °C with warming to ambient temperature gave three heterometallic products: 6a, the PPh3-for-CO substituted (PPh3)(CO)2Fe(μ-η3:η 2-C(O)C(Ph)=C=CH2)Ru(CO)Cp, and (PPh3)2Pt(μ3-η1:η 1:η3-C(Ph)CCH2)Ru(CO)Cp(μ 2-CO)Fe(CO)2 (8). All new products were characterized by a combination of IR and NMR (1H, 13C{1H}, and 31P{1H}) spectroscopy, FAB mass spectrometry, and elemental analysis; the structures of 1b, 3, 6a, and 8 were elucidated by X-ray diffraction analysis. Complexes 1b and 3 each contain a Pt-Ru bond and a μ-allenyl group that is η1 ligated to Pt and η2 ligated, through the internal C=C bond, to Ru. 6a contains an open Pt-Fe-Ru metal framework, with the μ-C(Ph)=C=CH2 ligand being attached η1 to Pt, η2 through the C(Ph)=C to Fe, and η2 through the C=CH2 to Ru. 8 is also an open, Pt-Fe-Ru bonded cluster; however, it contains an η3-allyl group ligated to Fe and metalated at CPh (Ru) and Cβ (Pt). Possible mechanisms of formation of the new μ-allenylmetal complexes are presented. Complexes 1 and 2 underwent fragmentation of the binuclear framework to yield Cp(CO)2MCH=C=CH2 (M = Ru, Fe), Cp(CO)2RuC(Ph)=C=CH2, or Cp-(CO)2FeCH2C≡CPh, as appropriate, in addition to Pt(PPh3)2(CO)2, upon treatment with CO at room temperature. The reverse of these processes can be effected by sweeping the product solutions with Ar for the three η1-allenyl complexes, but not for Cp(CO)2FeCH2C=CPh.
Control of the photochemistry of Ru3(CO)12 and Os3(CO)12 by variation of the solvent1
Leadbeater, Nicholas E.
, p. 211 - 216 (2007/10/03)
The synthetic potential of the photosubstitution of CO by two-electron donor ligands in M3(CO)12 [M=Ru, Os] has been investigated. When used as photolysis media, diethyl ether, ethyl acetate and acetonitrile act as photofragmentation quenchers allowing for the synthesis of photosubstitution products in high yield. UV photolysis of M3(CO)12 with added triphenylphosphine in these photolysis media leads to M3(CO)12-n(PPh3)n (n=1, 2 or 3). Prolonged photolysis with added tricyclohexylphosphine generates the highly sterically crowded complex M3(CO)9(PCy3)3. Photolysis with thiols, RSH (R=Et, Ph), leads to the thiolato complexes HM3(μ-SR)(CO)10, prolonged photolysis of which generates the corresponding sulphido cluster M3(μ3-S)(CO)10. Photolysis of M3(CO)12 in acetonitrile with no added ligand results in the generation of M3(CO)12-n(MeCN)n (n=1 or 2). This offers a route to these complexes without the need for the use of oxidising agents such as trimethylamine-N-oxide. Photolysis of an ethene-saturated diethyl ether or ethyl acetate solution of M3(CO)12 leads to no net photoreaction in the case of ruthenium, whereas, for osmium, the olefin complex Os(CO)4(η2-C2H4) is formed. This highlights the difference in the photosubstitution mechanism for Ru3(CO)12 and Os3(CO)12.
The photochemical generation of novel neutral mononuclear ruthenium complexes and their reactivity
Edwards, Andrew J.,Leadbeater, Nicholas E.,Lewis, Jack,Raithby, Paul R.
, p. 15 - 20 (2007/10/03)
The room-temperature photolysis of Ru3(CO)12 (1) in dichloromethane under a flow of ethylene affords the highly reactive complex Ru(CO)4(C2H4) (2) in a quantitative yield.The addition of MeCN to the reaction mixture, while the photolytic conditions and the ethylene flow are maintained, gives Ru(CO)3(C2H4)(NCMe) (3).If the irradiation is continued but the ethylene flow stopped, a different product, namely Ru(CO)3(NCMe)2 (4) is obtained.The addition of an excess of triphenylphosphine to a dichloromethane solution of 2 in the absence of ethylene and of light gives two phosphine-substituted products: Ru(CO)4(PPh3) (5) and Ru(CO)3(PPh3)2 (6).Under similar conditions, 3 affords 6 and the trinuclear cluster Ru3(CO)9(PPh3)3 (7) while, if MeCN is added instead of PPh3, the reactive cluster Ru3(CO)9(NCMe)3 (8) is obtained.If an excess of acrylonitrile is used instead of ethylene, the photolysis of 1 in dichloromethane yields Ru(CO)4(NCCH=CH2) (9) which reacts under photolytic conditions but in the absence of an excess of acrylonitrile with MeCN to give Ru(CO)3(NCCH=CH2)(MeCN) (10) and this product reacts with a second equivalent of acrylonitrile to afford Ru(CO)3(NCCH=CH2)2 (11).All the products have been characterized by IR spectroscopy and their structures established from symmetry considerations.Keywords: Ruthenium; Carbonyl; Nitrile; Photochemical synthesis
Synthesis and Structure of η4-Enone Complexes of Ruthenium(0)
Marcuzzi, Alessandro,Linden, Anthony,Philipsborn, Wolfgang von
, p. 976 - 987 (2007/10/02)
A variety of 4-enone)> complexes (L = phosphines, phosphites, and arsines, enone = (E)-4-phenylbut-3-en-2-one) have been synthesized. 1H, 13C-, and 31P-NMR spectra are reported and the X-ray structures of two Ru complexes with L = Ph3P (7), Et3P (10) and one Fe complex with L = Ph3P (14) are presented.All three compounds crystallize in the same monoclinic space group P21/n with a = 10.575(2) Angstroem, b = 9.213(2) Angstroem, and c = 27,608(5) Angstroem, β = 100,04(2) deg, Z = 4 for 7, a = 10,276(3) Angstroem, b = 12,935(3) Angstroem, and c = 14,854(2) Angstroem, β = 96,96(2) deg, Z = 4 for 10, and a = 10,492(2) Angstroem, b = 9,232(3) Angstroem, and c = 27,129(3) Angstroem, β = 98,67(2) deg, Z = 4 for 14.The structures of the Ru complexes are compared with the Fe analogues.In the case of M = Ru and L = (EtO)3P, (MeO)3P, and (i-PrO)3P (9, 11, and 13, respectively) stereoisomers could be detected by 31P-NMR at room temperature, which arise from rotation at the coordinated metal centre.
Carbonylation of the Ru-Me bond of Ru(Me)(I)(CO)2(iPr-N=CHCH=N-iPr) catalyzed by Ru(CO)4(PR3), ZnCl2, and H+
Kraakman, Marco J. A.,De Klerk-Engels, Barbara,De Lange, Paul P. M.,Vrieze, Kees,Smeets, Wilberth J. J.,Spek, Anthony L.
, p. 3774 - 3784 (2008/10/08)
Reaction of the dimetallic compound Ru2(Me)(I)(CO)4(PR3)(iPr-DAB) (iPr-DAB = iPr-N=C(H)C-(H)=N-iPr; PR3 = P(nBu)3 (2a), PMe2Ph (2b), PMePh2 (2c), PPh3 (2d), P(OMe)3 (2e), P(OPh)3 (2f)) with carbon monoxide afforded a mixture of the monomeric complexes Ru(R)(I)(CO)2(iPr-DAB) (R = Me (3); R = C(O)Me (4)) and Ru(CO)4(PR3) (5a-f). It was found that with increasing basicity of the phosphine there is a stronger tendency to form the acetyl product 4, although 3 is formed initially for all phosphines used. Mechanistic studies showed that the conversion of 3 to 4 is catalyzed by Ru(CO)4(PR3), provided PR3 is sufficiently basic. The use of 13CO-enriched Ru(CO)4(PR3) led to the incorporation of 13CO into both the acetyl CO group and the terminal CO groups of 4, indicating the presence of a dimetallic intermediate, by which intermetallic CO exchange becomes possible. Further evidence for this was obtained from the observation that the conversion of 3 to 4 can also be effected in the absence of free CO, by reaction of 3 with Ru(CO)4(PMe2Ph) (5b) and L′ (L′ = PPh3, P(OPh)3). In addition to 4 the complex Ru(CO)3(PMe2Ph)(L′) is also formed under these conditions. Interestingly, reaction of 3 with 5b in the absence of both CO and L′ also gave carbonylation of the Ru-Me bond, which, however, was accompanied by transfer of a H-atom from an iPr-CH group to an imine C-atom, with formation of Ru(C(O)Me)(I)(CO)2(iPr-N= CH-CH2-N=C(Me)2) (7). Reaction of 3 with AgOTF yielded [Ru(Me)(CO)2(iPr-DAB)][OTF] (8), which in the presence of CO is rapidly converted to [Ru(C(O)Me)(CO)2(iPr-DAB)][OTF] (9), whereas 8 with tBu isocyanide and PMe2Ph gave [Ru(Me)(CO)2(L)(iPr-DAB)][OTF] (L = tBu-NC (10), PMe2Ph (11)). Attempts to carbonylate the Ru-Me bond in complexes 10 and 11 were not successful. Finally it was shown that the carbonylation of the Ru-Me bond of 3 could also be promoted by H+ and ZnCl2. Single-crystal X-ray structure determinations of complexes 4 and 8 have been carried out, and their molecular structures are discussed. Salient features are that 4 has a configuration similar to that of 3; i.e., the acetyl group is trans to I. The trifluorosulfonate anion in 8 is found to be η1-coordinated to the ruthenium center and trans to the methyl group. Crystals of 4 (C12H19N2O3RuI) are monoclinic, space group P21/n, with a = 8.556 (1) A?, b = 18.510 (2) A?, c = 10.500 (1) A?, β = 94.90 (1)°, V = 1656.7 (3) A?3, Z = 4, and final R = 0.0435 for 2565 reflections with I > 2.5σ(I) and 188 parameters. Crystals of 8 (C12H19F3N2O5RuS) are monoclinic, space group P21/c, with a = 8.288 (1) A?, b = 25.839 (2) A?, c = 17.994 (1) A?, β = 100.47 (1)°, V = 3789.1 (6) A?3, Z = 8, and final R = 0.0476 for 3917 reflections with I > 2.5σ(I) and 500 parameters.
Oxygen atom transfer reactions to metal carbonyls. Kinetics and mechanism of CO substitution of M(CO)5 (M = Fe, Ru, Os) in the presence of (CH3)3NO
Shen, Jian-Kun,Gao, Yi-Ci,Shi, Qi-Zhen,Basolo, Fred
, p. 2144 - 2147 (2008/10/08)
Reported are rates of reaction and activation parameters for CO substitution by PPh3 of M(CO)5 (M = Fe, Ru, Os) in the presence of (CH3)3NO. The reactions follow a second-order rate law, being first-order in concentrations of M(CO)5 and of (CH3)3NO but zero-order in PPh3 concentration. The reaction rates show an approximate overall fourfold increase in the order Fe Ru > Os for M3(CO)12. An attempt is made to account for the relative reaction rates of the M(CO)5 compounds and for why the order differs from that of the corresponding metal carbonyl clusters.
Photofragmentation Kinetics of Some Triruthenium Carbonyl Clusters
Brodie, Nacy M. J.,Huq, Rokeya,Malito, John,Markiewicz, Stan,Poe, Anthony J.,Sekhar, Vasu C.
, p. 1933 - 1940 (2007/10/02)
The photokinetics of fragmentation reactions of with L=PPh3, P(OPh)3, AsPh3, CO, 1-octene, and methyl acrylate in a variety of solvents have been studied.Quantum yields increase to limiting values at high but the limiting values vary significantly with the nature of L.The low efficiency of photochlorination in chlorocarbon solvents, the absence of inhibition by CO of reactions with L=PPh3, and the absence of appropriate effects of varying incident light intersity all suggest that the first kinetically significant product is a non-radical reactive isomer of .This can revert to or react with L to form which itself can revert to or undergo fragmentation.The former choice governs the rate of increase with to a limiting quantum yield whereas the latter choice governs the dependence of the values of the limiting quantum yield on the nature of L.This scheme is also applicable to photoreactions of and the quantitative behaviour of the two clusters is not significantly different.Only lower limits for quantum yields for formation of the reactive isomers can be deduced from the data and it remains possible that the primary photophysical process is the formation of a very short-lived diradical by homolysis of a metal-metal bond.Photokinetic studies of reactions of with L (L=PPh3 or PBun3) are also reported.
Systematic substituent effects on dissociative substitution kinetics of Ru(CO)4L complexes (L = P-, As-, and Sb-donor ligands)
Chen, Lezhan,Po?, Anthony J.
, p. 3641 - 3647 (2008/10/08)
The kinetics of dissociation of CO from Ru(CO)4L (L = a wide variety of P-, As-, and Sb-donor ligands) have been studied, and the values of the rate constants can be resolved quantitatively into electronic and steric effects. The curved steric profile obtained shows that steric effects are quite small for small substituents such as P(OCH2)3CEt and P(OEt)3, but they increase steadily and substantially as the size of the substituent increases. A similar analysis of data in the literature for CO dissociative reactions of other substituted carbonyl complexes is also successful in resolving electronic and steric effects, and a clear dependence of steric effects on the coordination number of the complexes is shown. The analysis can be applied to some methyl migration reactions that involve CO loss, and the results can help to indicate the relative importance of CO loss and methyl migration in the transition states. Trends in the C-O stretching frequencies in the axial Ru(CO)4L and diaxial Ru(CO)3L2 complexes are described.
