Collect. Czech. Chem. Commun. 1979, 44, 401-405

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

Ľubica Adamčíková and Ľudovít Treindl

Department of Physical Chemistry, Comenius University, 816 50 Bratislava


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.