Ferric oxene complex

If the active oxidizing agent is not formulated as a ferric oxene complex, the questions then remain as to what is its electronic ground state and how does hydrocarbon oxidation occur ... 

The ferric oxene complex (6) is, of course, just one resonance formulation of 5 (see scheme 2). Moreover, the addition of dioxygen and two electrons to P-450 is equivalent to using... 

A more promising approach could be the interaction of ferric heme-sulfur complexes with oxene donors like 3-chloroperacetic acid, cumene hydroperoxide or iodoso-benzene, since cytochrome P450 seems to react with these compounds by formation of the active oxygen species. Attempts in this direction have been made, but so far... 

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