Rearrangement oxidation rate

With appropriate choices of kinetic constants, this approach can reproduce the NSC experimental data quite well. Park and Appleton [63] oxidized carbon black particles in a series of shock tube experiments and found a similar dependence of oxidation rate on oxygen concentration and temperature as NSC. Of course, the proper kinetic approach for soot oxidation by 02 undoubtedly should involve a complex surface reaction mechanism with distinct adsorption and desorption steps, in addition to site rearrangements, as suggested previously for char surface combustion. 

The question remains Is the formation of 133 or its destruction ratedetermining Experiment indicates that rearrangement is concerted and that in the oxidation of most ketones rearrangement is rate-determining. 

In a real system many reactions that fit into the general categories represented by 8.13 to 8.15 are possible. This is because the organic intermediates and products themselves may undergo further rearrangement, oxidation, and other reactions. Mechanistic studies for these reactions are therefore invariably based on kinetic models. In these models a set of reactions and associated rate constants are assumed. Through simulation and optimization methods the model is then refined so that best fit between observed and predicted data points are obtained. 

Experimented evidence has been obtained to support this mechanism. Thus, for example, Mahoney and Ferris [10] and Lloyd and Lange [11] report a three halves dependency of rate upon substrate concentration in the presence of inhibitor. In addition, the above equation can be rearranged to show that there should be a minimum oxidation rate at [AH] = (fe3/fcs)[RH], and an inflection point at [AH] = 3(fe3/fe5)[RH] at constant [RH] both have been observed experimentally [9]. 

However, rates in the ionic reaction covered a range of 10 , while oxidation rates Avith the same structure variation covered a range of only 10. The rearrangement of 4,4-dimethyl-l-pentene and the slow double-bond isomerization do indicate some acidic character for bismuth molybdate. On cuprous oxide, Enikeev, Isaev, and Margolis (143)... 

The oxidation rate of a pure metal may be calculated from self diffusion data. Conversely, oxidation kinetics may be used to calculate self diffusion data. Eq. (18) may be rearranged and the rate constant differentiated with respect to log oxygen pressure to yield... 

Presumably, the propane monooxygenase activity, present in Rhodococcus strains, oxidized vinyl chloride to chlorooxirane, which subsequently chemically rearranged to products that could be further oxidized to carbon dioxide. The data on the initial oxidation rates of various experiments, described by Malachowsky et al. [18], were... 

Slater type orbitals 59 Smiles rearrangement 688-691 photochemical 691 Solvent effect, on oxidation rate of K-butanethiol 808, 810 Solvolysis, of 2-chlorocyclohexanethiols 440... 

Small kinetic isotope effects [230-232], correlation of the oxidation rates with Hammett p-values [232, 236], and formation of rearranged products (Scheme IOC) [237-239] suggest the involvement of one electron transfer process from amines to the oxidants to afford aminium radicals [240]. Aminium radicals were detected during the oxidation of A,A -dimethylaniline by horseradish peroxidase. 

Imidazole, 4-acetyl-5-methyl-2-phenyl-synthesis, 5, 475 Imidazole, 1-acyl-reactions, 5, 452 rearrangement, 5, 379 Imidazole, 2-acyl-synthesis, 5, 392, 402, 408 Imidazole, 4-acyl-synthesis, 5, 468 Imidazole, C-acyl-UV spectra, 5, 356 Imidazole, N-acyl-hydrolysis rate constant, 5, 350 reactions, 5, 451-453 synthesis, 5, 54, 390-393 Imidazole, alkenyl-oxidation, 5, 437 polymerization, 5, 437 Imidazole, 1-alkoxycarbonyl-decarboxylation, 5, 453 Imidazole, 2-alkoxy-l-methyl-reactions, 5, 102 thermal rearrangement, 5, 443 Imidazole, 4-alkoxymethyl-synthesis, 5, 480 Imidazole, alkyl-oxidation, 5, 430 synthesis, 5, 484 UV spectra, 5, 355 Imidazole, 1-alkyl-alkylation, 5, 73 bromination, 5, 398, 399 HNMR, 5, 353 synthesis, 5, 383 thermal rearrangement, 5, 363 Imidazole, 2-alkyl-reactions, 5, 88 synthesis, 5, 469... 

Kubota and co-workers describe a novel oxidative rearrangement of the diosphenol (58) of 17iS-hydroxyandrost-4-ene-2,3-dione to the A-nor-A -1,2-diketone (59) in 33 % yield by the action of specially prep d manganese dioxide in boiling acetone. The rate of ring contraction is very sensitive to the source of the oxidant, and a trace of dilute sulfuric acid in the reaction mixture causes oxidative fission of ring A. 

Film rearrangement resulting in the formation of oxide subgrain and grain boundaries these paths of easy ion migration promote the formation of oxide islands and result in an increase in the growth rate of the oxide. 

The Pummerer reaction346 of conformationally rigid 4-aryl-substituted thiane oxides with acetic anhydride was either stereoselective or stereospecific, and the rearrangement is mainly intermolecular, while the rate-determining step appears to be the E2 1,2-elimination of acetic acid from the acetoxysulfonium intermediates formed in the initial acetylation of the sulfoxide. The thermodynamically controlled product is the axial acetoxy isomer, while the kinetically controlled product is the equatorial isomer that is preferentially formed due to the facile access of the acetate to the equatorial position347. The overall mechanism is illustrated in equation 129. 

Once the active Co catalyst has been formed by peracid oxidation of Co the next step is determined by the relative rates of reaction of this species with other species present in the solution, i.e. Mn, Br" and the substrate, and its rearrangement to the much less reactive Co . As can be seen from these data (Fig. 15), the relative rates of reaction of Co with Mn Br" and p-xylene are 940, 84 and 0.03, compared to 1 for the conversion of Co to Co (ref. 9). This means that in a mixture containing Co , Mn Br" and p-xylene, > 90% of Co reacts with Mn to afford Mn and that there is no reaction of Co with the p-xylene substrate. 

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