Salt effects upon the S2O82-+Ru(NH3)(5)pz(2+) electron transfer reaction

A study of the kinetic salt effects on the oxidation of Ru(NH3)(5)pz(2+) (P irazinepentaammineruthenium (II)) with S2O82- (Peroxodisulphate) was carrie d out. The components of the experimental rate constant, k(obs), were separ ated, and the true (unimolecular) electron transfer rate constant, k(et), i s (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 v ariations of k(et) and k(obs) when salt concentrations change. (C) 1999 Joh n Wiley & Sons, Inc.