Rate constants transition metal ions

It is necessary to note the limitation of the approach to the study of the polymerization mechanism, based on a formal comparison of the catalytic activity with the average oxidation degree of transition metal ions in the catalyst. The change of the activity induced by some factor (the catalyst composition, the method of catalyst treatment, etc.) was often assumed to be determined only by the change of the number of active centers. Meanwhile, the activity (A) of the heterogeneous polymerization catalyst depends not only on the surface concentration of the propagation centers (N), but also on the specific activity of one center (propagation rate constant, Kp) and on the effective catalyst surface (Sen) as well ... [Pg.176]

The values of the rate constants for the reactions of transition metal ions with hydrogen peroxide in an aqueous solution are presented in Table 10.2. [Pg.387]

Rate Constants of Transition Metal Ion Reactions with Hydrogen Peroxide in Aqueous Solutions... [Pg.387]

Rate Constants of the Reaction of Transition Metal Ions and Complexes with Hydroperoxides... [Pg.390]

In real systems (hydrocarbon-02-catalyst), various oxidation products, such as alcohols, aldehydes, ketones, bifunctional compounds, are formed in the course of oxidation. Many of them readily react with ion-oxidants in oxidative reactions. Therefore, radicals are generated via several routes in the developed oxidative process, and the ratio of rates of these processes changes with the development of the process [5], The products of hydrocarbon oxidation interact with the catalyst and change the ligand sphere around the transition metal ion. This phenomenon was studied for the decomposition of sec-decyl hydroperoxide to free radicals catalyzed by cupric stearate in the presence of alcohol, ketone, and carbon acid [70-74], The addition of all these compounds was found to lower the effective rate constant of catalytic hydroperoxide decomposition. The experimental data are in agreement with the following scheme of the parallel equilibrium reactions with the formation of Cu-hydroperoxide complexes with a lower activity. [Pg.393]

Peroxyl radicals with a strong oxidative effect along with ROOH are continuously generated in oxidized organic compounds. They rapidly react with ion-reducing agents such as transition metal cations. Hydroxyl radicals react with transition metal ions in an aqueous solution extremely rapidly. Alkyl radicals are oxidized by transition metal ions in the higher valence state. The rate constants of these reactions are collected in Table 10.5. [Pg.395]

Rate Constants of Free Radical Reactions with Transition Metal Ions and Complexes... [Pg.396]

Rate Constants of Oxidation of Transition Metal Ions by Dioxygen... [Pg.406]

Rate Constants and Activation Parameters for Solvent Exchange on First-Row Divalent Transition-metal Ions... [Pg.19]

Effect of Non-leaving Ligands on the Solvent Exchange Rate Constants on Second and Third Row Trivalent Transition-metal Ions... [Pg.36]

Consider the striking effect of glycerol in reducing the solvent exchange rate constant (Sec. 4.2(a)) of all the first row transition metal ions. [Pg.123]

Rate Constants and Activation Parameters for Water Exchange on Trivalent First Row Transition Metal Ions [M(H20)6] ... [Pg.346]

Rate Constants and Activation Volumes eor Weter Exchange on Trivalent Hexa-aqua Transition Metal Ions and Their Conjugate... [Pg.352]

Replacing one or more water molecules from the first coordination shell of a di- or a trivalent transition metal ion by a kinetically inert mono-or multi-dentate ligand can have a strong effect on the exchange rate constant of the remaining water molecules. In general the remaining water molecules become more labile (Tables VII and VIII) the acceleration can... [Pg.353]