Thermodynamics of Formation of Ru(III) and Ru(IV)-μ-Peroxo Complexes

Abstract
Reaction of one half and one equivalents of H2O2 with K[RuIII(pdta-H)Cl].2H2O gives rise to the μ-peroxo complexes [RuIII (pdta-H)]2H2O2 and [RuIV(pdta-H)]2O2, respectively. Equilibrium constants for the formation of the various peroxo species were determined between pH 3-11, in the temperature range 283-313 K and with μ = 0.10 M in KC1. The existence of the various peroxo species was substantiated by potentiometry, spectrophotometry and electrochemical studies. Thermodynamic quantities associated with the formation of the (pdta)RuIII and (pdta)RuIV-μ-peroxo species and their hydrolysis products are reported.