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Ru Complex (ru + complex)

Distribution by Scientific Domains

Chemistry	76%
Polymers and Materials Science	15%

Selected Abstracts

Alternating copolymerization of propylene oxide with carbon monoxide catalyzed by Co complex and Co/Ru complexes

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 24 2002
Daisuke Takeuchi
Abstract Co2(CO)8 catalyzes the ring-opening copolymerization of propylene oxide with CO to afford the polyester in the presence of various amine cocatalysts. The 1H and 13C{1H} NMR spectra of the polyester, obtained by the Co2(CO)8,3-hydroxypyridine catalyst, show the following structure [CH2CH(CH3)OCO]n. The Co2(CO)8,phenol catalyst gives the polyester, which contains the partial structural unit formed through the ring-opening copolymerization of tetrahydrofuran with CO. The bidentate amines, such as bipyridine and N,N,N,,N,-tetramethylethylenediamine, enhance the Co complex-catalyzed copolymerization, which produces the polyester with a regulated structure. Acylcobalt complexes, (RCO)Co(CO)n (R = Me or CH2Ph), prepared in situ, do not catalyze the copolymerization even in the presence of pyridine. This suggests that the chain growth involves the intermolecular nucleophilic addition of the OH group of the intermediate complex to the acyl,cobalt bond, forming an ester bond rather than the insertion of propylene oxide into the acyl,cobalt bond. Co2(CO)8Ru3(CO)12 mixtures also bring about the copolymerization of propylene oxide with CO. The molar ratio of Ru to Co affects the yield, molecular weight, and structure of the produced copolymer. The catalysis is ascribed to the RuCo mixed-metal cluster formed in the reaction mixture. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4530,4537, 2002 [source]

Repetitive Application of a Fluorous Chiral BINAP,Ru Complex in the Asymmetric Hydrogenation of Olefins

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 13 2007
Joachim Horn
Abstract A trisperfluoroalkylsilyl-modified (S)-BINAP ligand has been prepared and its pertinent Ru complex applied to the asymmetric hydrogenation of olefins. Efficient separation of the Ru catalyst by filtration and its reuse was achieved. Relative to the untagged complex with a Ru-leaching of 300 ppm, leaching into the product was low (1.6,4.9 ppm). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]

ChemInform Abstract: Enantioselective Hydrogenation of Aromatic Ketones Catalyzed by Ru Complex Using a New Bipyridyl Diphosphine.

CHEMINFORM, Issue 23 2008
Li Chen
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Towards Long-Living Metathesis Catalysts by Tuning the N-Heterocyclic Carbene (NHC) Ligand on Trifluoroacetamide-Activated Boomerang Ru Complexes

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 25 2009
Hervé Clavier
Abstract The synthesis and characterization of three novel trifluoromethylamido-containing "boomerang" precatalysts bearing various N-heterocyclic carbene (NHC) ligands are reported. Comparative kinetic and stability studies show the significant effect of the NHC on the catalyst reaction profile. An investigation of the reaction scope for diverse metathesis transformations has allowed us to establish the influence of the NHC on catalyst activity, especially as a function of substrate steric bulk. The excellent stability of one of the novel precatalysts is disclosed, and allowed for its recovery at the end of catalytic reactions. Large-scale ring-closing metathesis, enyne-metathesis and cross-metathesis experiments have revealed the recoverability of the catalyst. ICP-MS analyses of the synthesized products reveal Ru contamination levels of less than 2.5 ppm.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]

ChemInform Abstract: Towards Long-Living Metathesis Catalysts by Tuning the N-Heterocyclic Carbene (NHC) Ligand on Trifluoroacetamide-Activated Boomerang Ru Complexes.

CHEMINFORM, Issue 2 2010
Herve Clavier
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Repetitive Application of a Fluorous Chiral BINAP,Ru Complex in the Asymmetric Hydrogenation of Olefins

Location-dependent controlled release kinetics of model hydrophobic compounds from mesoporous silicon/biopolymer composite fibers

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 6 2009
Dongmei Fan
Abstract In this study, biodegradable mesoporous Si (BioSiliconTM) was loaded with cis-(2,2,-bipyridine) dichlororuthenium (II) (Ru complex) as a model hydrophobic compound. This ruthenium complex-loaded BioSiliconTM was either partially embedded on the surface of electrospun polycaprolactone (PCL) fibers or fully encapsulated within the fibers. To study release profiles in the above model delivery systems, porous Si/PCL constructs were soaked in DI water at 37 °C and the UV,Vis absorption spectrum of the supernatant was measured as a function of time. These results show that the Ru complex was released in a sustained manner over 7-day period. In addition, it is shown that the controlled-release of this complex depends on both the spatial location of the complex in the PCL fibrous scaffolds as well as the amount of Ru compound loaded in the mesoporous Si. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Chemistry of Ru(& 6 -1,3,5-cyclooctatriene)(,2 -dimethyl fumarate)2

THE CHEMICAL RECORD, Issue 3 2006
Take-Aki Mitsudo
Abstract The chemistry of a novel zerovalent Ru complex, Ru(,6 -cot)(,2 -dmfm)2 (1) (cot=1,3,5-cyclooctatriene; dmfm=dimethyl fumarate), is reviewed with a focus on its reactivity toward phosphines, amines, and H2O, as well as arenes and p -quinones. A variety of novel zerovalent Ru complexes were synthesized from Ru(,6 -cot)(,2 -dmfm)2 (1), and it was shown that the complexes preferably bear both electron-donating and -accepting ligands simultaneously to exhibit thermodynamic stability. The first isolable zerovalent Ru aqua complexes were successfully prepared, and in these complexes, the generation of a chiral center on the O atom of the coordinated H2O was disclosed. In addition, the characteristic catalytic activity of 1 in organic synthesis was considered by reviewing recently developed novel reactions: (i) dimerization of 2,5-norbornadiene to pentacyclo[6.6.0.02,6.03,13.010,14]tetradeca-4,11-diene (PCTD), (ii) intramolecular hydroamination of aminoalkynes to cyclic imines, (iii) formal [4+2] cycloaddition of alkynes with dmfm to trans -4-cyclohexene-1,2-dicarboxylates, and (iv) co-dimerization of dihydrofurans with ,,,-unsaturated esters to 2-alkylidenetetrahydrofurans. The products obtained here are expected to be used as novel functional organic monomers. © 2006 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 6: 107,116; 2006: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20076 [source]

Decomposition of Formic Acid Catalyzed by a Phosphine-Free Ruthenium Complex in a Task-Specific Ionic Liquid

CHEMCATCHEM, Issue 10 2010
Jackson D. Scholten
Abstract The dehydrogenation of formic acid is effectively catalyzed by the Ru complex [{RuCl2(p -cymene)}2] dissolved in the ionic liquid (IL) 1-(2-(diethylamino)ethyl)-3-methylimidazolium chloride at 80,°C without additional bases. This catalytic system gives TOF values of up to 1540,h,1. Preliminary kinetic insights show formal reaction orders of 0.70(±0.15), 0.78(±0.03) and 2.00(±0.17) for the Ru catalyst, IL,1, and formic acid, respectively. The apparent activation energy of this process is estimated to be (69.1±7.6),kJ,mol,1. In addition, dimeric Ru hydride ionic species involved in the reaction, such as [{Ru(p -cymene)}2{(H),-(H)-,-(HCO2)}]+ and [{Ru(p -cymene)}2{(H),-(Cl),-(HCO2)}]+, are identified by mass spectrometry. The presence of water in large amounts inhibits higher conversions. Finally, a remarkable catalytic activity is observed during recycles, indicating this system's potential for hydrogen gas production. [source]

Preparation of Pt,Ru Alloyed Thin Films Using a Single-Source CVD Precursor,

CHEMICAL VAPOR DEPOSITION, Issue 3 2003
S.-F. Huang
Abstract Treatment of (dimethylaminomethyl)ruthenocene with cis -Pt(DMSO)2Cl2 led to the formation of a ruthenocenyl platinum complex [CpRu(,5 -C5H3CH2NMe2)Pt(DMSO)Cl] (1); subsequent treatment of 1 with [Na(hfac)] afforded an air-stable Pt,Ru complex [CpRu(,5 -C5H3CH2NMe2)Pt(hfac)] (2). Its volatility and other physical data relevant to CVD experiments were assessed by thermogravimetric analysis (TGA). The Pt,Ru thin films were then deposited at two deposition temperatures, 300,°C and 400,°C, using O2 as the reactive carrier gas. The as-deposited thin films were characterized using energy dispersive X-ray (EDX), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). Results indicated the formation of a homogeneous Pt,Ru solid solution at the lower deposition temperature. However, upon raising the temperature to 400,°C, phase separation between Pt and Ru occurred, which then induced the growth of RuO2 grains at the substrate surface and caused depletion of the alloy in ruthenium. The electrocatalytic activities of the films, in respect of methanol oxidation, were investigated, in half-cell experiments, by cyclic voltammetry. [source]

Bulky Achiral Triarylphosphines Mimic BINAP in Ru(II)- Catalyzed Asymmetric Hydrogenation of Ketones

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2005
Qing Jing
Abstract In the present work, we report on catalysis of the enantioselective hydrogenation of ketones with Ru(II) complexes composed of cheap achiral monodentate phosphine ligands in combination with an enantiopure 1,2-diamine, affording a variety of optically active secondary alcohols with high efficiency and enantioselectivity. The steric impact of achiral monophosphine ligands in Ru complexes was found to be a critical factor for the high enantioselectivity of the reaction. This finding throws some light on a long-standing challenge, the high cost of chiral bisphosphine ligands, associated with an industrial application of the asymmetric hydrogenation of ketones. [source]

Density functional computations of 99Ru chemical shifts: relativistic effects, influence of the density functional, and study of solvent effects on fac,[Ru(CO)3I3],

MAGNETIC RESONANCE IN CHEMISTRY, Issue 11 2006
Jochen Autschbach
Abstract Solvent effects on the 99Ru NMR chemical shift of the complex fac,[Ru(CO)3I3], are investigated computationally using density functional theory. Further, benchmark calculations of the 99Ru shift for a set of ten Ru complexes have been performed in order to calibrate the computational model and to determine the importance of relativistic effects on the 99Ru nuclear magnetic shielding and on the chemical shift. A computational model for fac,[Ru(CO)3I3], that includes both explicit solvent molecules and a continuum model is shown to yield the best agreement with experiment. Relativistic corrections are shown to be of minor importance for determining 99Ru chemical shifts. On the other hand, the nature of the density functional is of importance. In agreement with literature data for ligand trends of 99Ru chemical shifts, the chemical shift range for different solvents is also best reproduced by a hybrid functional. Copyright © 2006 John Wiley & Sons, Ltd. [source]