Oxoiron Porphyrin Species with High‐Valent Iron: Formation by Solvent‐Dependent Protonation of a Peroxoiron(III) Porphyrinate Derivative

Activation of O₂ by cytochrome P‐450 monooxygenase is generally thought to proceed by way of a peroxoiron(III) porphyrinate species that is then transformed into an oxoiron(IV) porphyrinate radical cation. Such a radical cation, the “picket fence” model compound 1, has now been isolated for the first time from the peroxoiron(III) species by treatment with HBF₄ · Et₂O. (Figure Presented.)