A study of some redox reactions of the chromium(II)–ethylenediamine-tetra-acetate complex. Evidence for outer-sphere mechanisms

1968 ◽  
Vol 0 (0) ◽  
pp. 2847-2850 ◽  
Author(s):  
R. N. F. Thorneley ◽  
B. Kipling ◽  
A. G. Sykes
Keyword(s):  
Redox Reactions ◽  
Outer Sphere ◽  
Acetate Complex

Kinetics and mechanism of redox reactions of U(III) ions with monochloroacetic and dichloroacetic acids

1979 ◽  
Vol 44 (2) ◽  
pp. 401-405 ◽  
Author(s):  
Ľubica Adamčíková ◽  
Ľudovít Treindl
Keyword(s):  
Redox Reactions ◽  
Reaction Rate ◽  
Activation Parameters ◽  
Outer Sphere ◽  
Alcohol Concentration ◽  
Kinetics And Mechanism ◽  
Solvent Structure ◽  
Influence Of Ph ◽  
Sphere Mechanism

The kinetics and mechanism of the redox reactions of U3+ ions with mono- and dichloroacetic acids were studied. The influence of pH was observed mainly in the second case and led to the determination of the rate constants and activation parameters corresponding to two parallel steps, namely oxidation of U3+ with CHCl2COO- ions and oxidation of U3+ with CHCl2.COOH molecules. The influence of binary mixtures of water with methanol, ethanol, isopropanol, or tert-butenol on the reaction rate was followed. Increasing alcohol concentration influences the rate constant not only through changing dielectric constant and solvation of the reactants but also through a change of the solvent structure which plays a role in reactions with an outer sphere mechanism of the electron transfer.

Reactions of ozone and intermediate products of its decomposition with actinides, lanthanides and transition metals in aqueous solutions

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Boris G. Ershov ◽  
Bladimir P. Shilov
Keyword(s):  
Transition Metals ◽  
Aqueous Solutions ◽  
Redox Reactions ◽  
Outer Sphere ◽  
Ozone Decomposition ◽  
Decomposition Products ◽  
Coordination Spheres ◽  
Anions And Cations ◽  
The Stability ◽  
Mechanisms Of Reactions

Abstract The properties and stability of ozone in aqueous solutions of various compositions in the рН range of 0–14 were considered. The effect of anions and cations, which are involved in the redox reactions of actinides, on the stability of ozone and its reactivity has been studied. The reactions of О3 with ions of d- and f-elements were analyzed. Depending on the solution composition and рН value, the reaction can occur directly with the O3 molecule (direct mechanism) and/or with short-lived ion-radical products (•OH, HO 2 • / O 2 − • ${\text{HO}}_{2}^{{\bullet}}/{\text{O}}_{2}^{-{\bullet}}$ , H2O2/ HO 2 − ${\text{HO}}_{2}^{-}$ , O 3 − • ${\text{O}}_{3}^{-{\bullet}}$ ) formed upon ozone decomposition in water (indirect mechanism). Ions with inert coordination sphere react with О3 in the outer-sphere fashion with electron transfer. Polyvalent ions with labile coordination spheres are oxidized in acidic medium via О atom transfer, possibly, with intermediate peroxy addition (H2O2, HNO4, H2SO5, etc.). In alkaline medium, О3 is converted to the O 3 − • ${\text{O}}_{3}^{-{\bullet}}$ radical ion, which is the key oxidant for actinides. The results of studies and the mechanisms of reactions of ozone and its intermediates decomposition products with U, Np, Pu, and Am in various oxidation states and with some transition metals (Fe, Mn, Ag, Co, etc.) in aqueous solutions are presented and discussed.

Distinguishing between outer-sphere and inner-sphere redox mechanism on the basis of the solvent effect

1980 ◽  
Vol 45 (12) ◽  
pp. 3266-3269 ◽  
Author(s):  
Ľudovít Treindl ◽  
Ľubica Adamčíková
Keyword(s):  
Redox Reactions ◽  
Reaction Rate ◽  
Molar Fraction ◽  
Kinetic Studies ◽  
Outer Sphere ◽  
Diagnostic Value ◽  
Tert Butanol ◽  
Influence Of Water ◽  
Water Alcohol ◽  
Sphere Mechanism

During kinetic studies of redox reactions of U3+ ions, we paid special attention to the influence of water-alcohol binary mixtures on the reaction rate. Kinetic data suggest that the water-tert-butanol system is of a high diagnostic value. The dependence of log kexp on the molar fraction of tert-butanol passes through a characteristic minimum in the case of an outer-sphere mechanism, whereas in the other case it decreases monotonously.

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