14741-36-7Relevant articles and documents
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
, p. 2746 - 2757 (2016)
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.
Huq, Rokeya,Poae, Anthony J.,Chawla, Sudhir
, p. 121 - 126 (1980)
Keeton, David P.,Malik, Sher K.,Poe, Anthony
, (1977)
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 (1995)
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
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.
Ligand-controlled regio- and stereoselective addition of carboxylic acids onto terminal alkynes catalyzed by carbonylruthenium(0) complexes
Tan, Sze Tat,Fan, Wai Yip
, p. 4631 - 4635 (2011/02/27)
The addition of carboxylic acids onto terminal alkynes was catalyzed by mononuclear ruthenium(0) complexes to give enol esters in high yields. By using ligands with different electronic properties, product selectivity was achieved. E-enol esters were preferentially produced when tricarbonyl(η4- diene)ruthenium complexes were used; while geminal enol esters were produced when tricarbonylbis(phosphane)ruthenium complexes were used. Product selectivity is a major problem in transition metal-catalyzed hydrocarboxylation reactions. In this paper we report the ability of Ru(CO)3L2 (where L is a 2 e-donor) to catalyze the addition of variouscarboxylic acids onto terminal alkynes. A direct relationship between the regioselectivity of the product and the electronic property of the catalysis metal centre was observed.
