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,Nu0001,Nu0001-tetramethyl-p-phenylenediamine (TMPPD) are measured in waternby means of stopped-flow techniques using different inorganic ions, like Fe(CN)6n3u0002, MnO4nu0002, Co(NH3)6n3u0003, Ru(OH)n3u0003n6.nThe rates do not depend on the different oxidation potentials, but can be correlated well with calculated ratenconstants from the Marcus cross-relation.nThe electron self-exchange rates of the inorganic oxidants range over nine orders of magnitude. Measurementsnwere performed at T = 293 K within a pH-range of 7–9.