On the chemical properties of the transient complexes LmMn+1–OOR: Part I. The case of (2,3,9,10-tetramethyl-1,4,8,11-tetraazacyclotetradeca-1,3,8,10-tetraene)(H2O)CoIII–OOCH3 2+

The transient complex (2,3,9,10-tetramethyl-1,4,8,11-tetraazacyclotetradeca-1,3,8,10-tetraene)(H2O)CoIII–OOCH3 2+, (tim)(H2O)CoIII–O2CH3 2+, was prepared via the reaction of CoII(tim)(H2O)2 2+ with methylperoxyl radicals, applying radiation chemistry techniques. The transient complex decomposes mainly via a ‘Fenton-like’ reaction with excess CoII(tim)(H2O)2 2+, k=16±1 M−1 s−1. The transient complex reacts with the CH3O2radical dot radicals, k=(1.4±0.3)×109 M−1 s−1 to form CoII(tim)(H2O)2 2+ and formaldehyde. This reaction is surprisingly fast and if this rate is typical for analogous reactions these reactions have to be considered in a variety of radical induced oxidation processes. The plausible role of analogous reactions in oxidation processes by peroxides and dioxygen, which are catalyzed by cobalt complexes, is discussed.