Application of Marcus cross-relation to mixed inorganic-organic redox couples. A stopped-flow study of the oxidation of N,N,N ',N '-tetramethyl-p-phenylenediamine with various oxidants

摘要

The rate constants of the oxidation of N,N,N',N'-tetramethyl-p-phenylenediamine (TMPPD) are measured in water by means of stopped-flow techniques using different inorganic ions, like Fe(CN)(6)(3-), MnO4, Co(NH3)(6)(3-), Ru(OH)(6)(3-) The rates do not depend on the different oxidation potentials, but can be correlated well with calculated rate constants from the Marcus cross-relation. The electron self-exchange rates of the inorganic oxidants range over nine orders of magnitude. Measurements were performed at T=293 K within a pH-range of 7-9. [References: 36]