Kinetics of acetyl radical formation from methyl radicals and carbon monoxide and crystal structures of two acetylcobalt complexes

1992 ◽  
Vol 31 (24) ◽  
pp. 4959-4964 ◽  
Author(s):  
Andreja Bakac ◽  
James H. Espenson ◽  
Victor G. Young
Keyword(s):  
Carbon Monoxide ◽  
Crystal Structures ◽  
Radical Formation ◽  
Methyl Radicals ◽  
Acetyl Radical ◽  
Kinetics Of

scholarly journals Mo(CO)5Py as an Initiator of Polymerization

1967 ◽  
Vol 22 (6) ◽  
pp. 580-586 ◽  
Author(s):  
C. H. Bamford ◽  
R. Denyer ◽  
G. C. Eastmond
Keyword(s):  
Carbon Monoxide ◽  
Free Radical ◽  
Methyl Methacrylate ◽  
Vinyl Monomer ◽  
Radical Formation ◽  
Organic Halide ◽  
Organic Halides ◽  
Free Radical Formation ◽  
Molybdenum Carbonyl ◽  
Kinetics Of

In a series of publications we have described the kinetics of free-radical formation from molybdenum carbonyl in association with organic halides in a number of electron-donating solvents. Radical formation involves the displacement of carbon monoxide from the carbonyl by the solvent or vinyl monomer in a rate-determining process giving rise to complexes of the type Mo (CO)5L (where L represents the solvent or monomer) which then react directly with the halide. This paper describes a study of the behaviour of Mo (CO)5Py in association with organic halides in methyl methacrylate solution. The results show that Mo (CO)5Py does not react directly with the halide but first undergoes activation by reaction with monomer, mainly with displacement of pyridine. The relative reactivities of complexes of the type Mo (CO)5L are discussed.The mechanism previously proposed to account for the inhibition processes observed in Mo (CO) 6-organic halide systems satisfactorily explains the extensive inhibition observed in the present work.

The mechanism of the acetaldehyde pyrolysis

1967 ◽  
Vol 297 (1450) ◽  
pp. 365-375 ◽  
Keyword(s):  
Carbon Monoxide ◽  
Main Chain ◽  
Small Contribution ◽  
Methyl Radicals ◽  
Additional Source ◽  
Elementary Processes ◽  
Order Coefficient ◽  
Kinetics Of Formation ◽  
Low Pressures ◽  
Kinetics Of

Previous work on the acetaldehyde pyrolysis is shown to be vitiated by the presence, in the acetaldehyde, of impurities, mainly ethanol and crotonaldehyde. The reaction has been reinvestigated with the use of acetaldehyde, prepared from paraldehyde, which is free from these and other impurities. On the basis of a study of the kinetics of formation of the major products (methane and carbon monoxide) and of a number of minor products (hydrogen, acetone, propionaldehyde, ethane and ethylene) a reaction mechanism is proposed. This includes all of the reactions in the original Rice-Herzfeld scheme, together with a number of other elementary processes, in particular CH 3 + CH 3 CHO → CH 4 + CH 2 CHO. The decomposition of the radical CH 2 CHO into CH 2 CO and H provides an additional source of hydrogen, the rate of production of which is therefore not a measure of the rate of the initiation process. Acetone is believed to arise mainly by the reaction CH 3 + CH 3 CHO → CH 3 COCH 3 + H, and only to a negligible extent by the combination of CH 3 and CH 3 CO. The main chain-ending step is concluded to be CH 3 + CH 3 → C 2 H 6 , with a small contribution from CH 3 + CH 2 CHO → CH 3 CH 2 CHO. The work provides further evidence for the falling off, at low pressures, of the second order coefficient for the combination of methyl radicals. Rate constants for various elementary processes are deduced from the rates of formation of the various products, and are shown to be consistent with values obtained directly.

Study of nickel-molybdenum catalysts for methanation of carbon monoxide

1980 ◽  
Vol 45 (3) ◽  
pp. 783-790 ◽  
Author(s):  
Petr Taras ◽  
Milan Pospíšil
Keyword(s):  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Mixed Oxides ◽  
Minor Component ◽  
Fast Neutrons ◽  
Scanning Calorimetry ◽  
Low Concentrations ◽  
Γ Rays ◽  
Molybdenum Catalysts ◽  
Kinetics Of

Catalytic activity of nickel-molybdenum catalysts for methanation of carbon monoxide and hydrogen was studied by means of differential scanning calorimetry. The activity of NiMoOx systems exceeds that of carrier-free nickel if x < 2, and is conditioned by the oxidation degree of molybdenum, changing in dependence on the composition in the region Mo-MoO2. The activity of the catalysts is adversely affected by irradiation by fast neutrons, dose 28.1 Gy, or by γ rays using doses in the region 0.8-52 kGy. The system is most susceptible to irradiation in the region of low concentrations of the minor component (about 1 mol.%). The dependence of changes in catalytic activity of γ-irradiated samples on the dose exhibits a maximum in the range of 2-5 kGy. The changes in catalytic activity are stimulated by the change of reactivity of the starting mixed oxides, leading to different kinetics of their reduction and modification of their adsorption properties. The irradiation of the catalysts results in lowered concentration of the active centres for the methanation reaction.

Kinetics of catalytic reduction of nitrogen oxide by carbon monoxide on CuO/Al2O3 catalyst

1983 ◽  
Vol 48 (11) ◽  
pp. 3202-3208 ◽  
Author(s):  
Zdeněk Musil ◽  
Vladimír Pour
Keyword(s):  
Carbon Monoxide ◽  
Nitrogen Oxide ◽  
Rate Equation ◽  
Catalytic Reduction ◽  
Zero Order ◽  
Spectroscopic Measurements ◽  
First Order ◽  
Ir Spectroscopic ◽  
Kinetics Of ◽  
Al2o3 Catalyst

The kinetics of the reduction of nitrogen oxide by carbon monoxide on CuO/Al2O3 catalyst (8.36 mass % CuO) were determined at temperatures between 413 and 473 K. The reaction was found to be first order in NO and zero order in CO. The observed kinetics are consistent with a rate equation derived from a mechanism proposed on the basis of IR spectroscopic measurements.

Kinetics of carbon monoxide methanation on a Ni/SiO2 catalyst

1990 ◽  
Vol 55 (7) ◽  
pp. 1678-1685
Author(s):  
Vladimír Stuchlý ◽  
Karel Klusáček
Keyword(s):  
Carbon Monoxide ◽  
Reaction Rate ◽  
Catalyst Activity ◽  
Adsorbed Hydrogen ◽  
Reaction Products ◽  
Co Methanation ◽  
Molar Ratios ◽  
Rate Determining Step ◽  
Higher Temperature ◽  
Kinetics Of

Kinetics of CO methanation on a commercial Ni/SiO2 catalyst was evaluated at atmospheric pressure, between 528 and 550 K and for hydrogen to carbon monoxide molar ratios ranging from 3 : 1 to 200 : 1. The effect of reaction products on the reaction rate was also examined. Below 550 K, only methane was selectively formed. Above this temperature, the formation of carbon dioxide was also observed. The experimental data could be described by two modified Langmuir-Hinshelwood kinetic models, based on hydrogenation of surface CO by molecularly or by dissociatively adsorbed hydrogen in the rate-determining step. Water reversibly lowered catalyst activity and its effect was more pronounced at higher temperature.

Halides of Macrocyclic Silver(II) Complexes: Crystal Structures with Hydrogen Bond Network and Reaction Kinetics of the Decomposition

2021 ◽  
pp. 120431
Author(s):  
Akinori Honda ◽  
Shunta Kakihara ◽  
Shuhei Ichimura ◽  
Kazuaki Tomono ◽  
Mina Matsushita ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Reaction Kinetics ◽  
Crystal Structures ◽  
Hydrogen Bond Network ◽  
Bond Network ◽  
Kinetics Of

Bis(1-phenyl-1-propyne) complexes of tungsten(II): crystal structures of [WI2(CO)(NCR)(η2-MeC2Ph)2] (R = Me, Et, or Ph)

2001 ◽  
Vol 79 (3) ◽  
pp. 263-271
Author(s):  
Paul K Baker ◽  
Michael GB Drew ◽  
Deborah S Evans
Keyword(s):  
Carbon Monoxide ◽  
Solid State ◽  
Crystal Structures ◽  
Octahedral Geometry ◽  
X Ray ◽  
X Ray Crystallography ◽  
Alkyne Complexes ◽  
First Time

Reaction of [WI2(CO)3(NCMe)2] with two equivalents of 1-phenyl-1-propyne (MeC2Ph) in CH2Cl2, and in the absence of light, gave the bis(1-phenyl-1-propyne) complex [WI2(CO)(NCMe)(η2-MeC2Ph)2] (1) in 77% yield. Treatment of equimolar quantities of 1 and NCR (R = Et, i-Pr, t-Bu, Ph) in CH2Cl2 afforded the nitrile-exchanged products, [WI2(CO)(NCR)(η2-MeC2Ph)2] (2-5) (R = Et (2), i-Pr (3), t-Bu (4), Ph (5)). Complexes 1, 2, and 5 were structurally characterized by X-ray crystallography. All three structures have the same pseudo-octahedral geometry, with the equatorial sites being occupied by cis and parallel alkyne groups, which are trans to the cis-iodo groups. The trans carbon monoxide and acetonitrile ligands occupy the axial sites. In structures 1 and 2, the methyl and phenyl substituents of the 1-phenyl-1-propyne ligands are cis to each other, whereas for the bulkier NCPh complex (5), the methyl and phenyl groups are trans to one another. This is the first time that this arrangement has been observed in the solid state in bis(alkyne) complexes of this type.Key words: bis(1-phenyl-1-propyne), carbonyl, nitrile, diiodo, tungsten(II), crystal structures.

Kinetics of γ-alumina chlorination by carbon monoxide and chlorine

1982 ◽  
Vol 52 (1-3) ◽  
pp. 211-215 ◽  
Author(s):  
A. Tóth ◽  
I. Bertóti ◽  
T. Székely
Keyword(s):  
Carbon Monoxide ◽  
Kinetics Of
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