Salt effects upon the S2O82? + Ru(NH3)5pz2+ electron transfer reaction

Abstract

A study of the kinetic salt effects on the oxidation of Ru(NH 3 ) 5 pz 2ϩ (Pirazinepentaammineruthenium (II)) with (Peroxodisulphate) was carried out. The components of 2Ϫ S O 2 8 the experimental rate constant, k obs , were separated, and the true (unimolecular) electron transfer rate constant, k et , is (approximately) obtained. An analysis of the main parameters controlling the variations of k et , the free energies of reaction and reorganization, is made. Both parameters show a compensating behavior, so there are small variations of k et and k obs when salt concentrations change.

Salt and Solvent Effects on the Kinetics of the Oxidation of the Excited State of the [Ru(bpy)3]2+ Complex by S2O82-

“…Second, as was recently shown by Simonin and Hendrawan, 6 k D (and k -D ) can be calculated to a reasonable accuracy by employing an exponential mean spherical approach (EMSA). Third, redox potentials of the S 2 O 8 2-/3couple in the reaction media studied here are available 7,8 so that by measuring the redox potentials of the [Ru(bpy) 3 ] 3+/2+ couple in these media, the reaction free energy can be calculated.…”

Binding of Ru(NH3)5pz2+ to 4-Sulfocalix[4]arene Sodium Salt. Effects of the Host−Guest Interaction on Electron Transfer Processes

“…That is, the rate constant for the process reactants → products contains contributions from the above steps. The factorization into the different contributions can be done by selecting suitable systems: Thus, if the reaction is accompanied by a major decrease in the free energy, as happens with the processes studied here, the contributions from the second and third steps and the reverse process of the second one can be ignored. Nonetheless, the observed rate constant still has contributions from the forward and backward processes of the first step and, of course, from the forward process in the second step.…”