Peroxo-iron

J.-J. Girerd, F. Banse, and A. J. Simaan, Characterization and Properties of Non-Heme Iron Peroxo Complexes in Metal-... 

Messerschmidt A (1998) Metal Sites in Small Blue Copper Proteins, Blue Copper Oxidase and Vanadium-Containing Enzymes. 90 37-68 Meunier B, Bernadou J (2000) Active Iron-Oxo and Iron-Peroxo Species in Cytochromes P-450 and Peroxidases Oxo-Hydroxo Tautomerism with Water-Soluble Metal-loporphyrins. 97 1-36... 

Wertz DL, Valentine JS (2000) Nucleophilicity of Iron-Peroxo Porphyrin Complexes. 97 37-60... 

Wertz, D. L. Valentine, J. S. Nucleophilicity of iron-peroxo porphyrin complexes. Struct. Bond. 2000, 97, 38-60. 

Meunier, B. and J. Bernadou (2000). Active iron-0X0, and iron-peroxo species in cytochrome P450 and peroxidases oxo-hydroxo tautomerism with water-soluble porphyrins. In B. Meunier and Waldemar Adam (ed.). Metal-Oxo and Metal-Peroxo Species in Catalytic Oxidations, Vol. 97. Springer-Verlag, Berlin, pp. 1-35. 

The stability of iron-peroxo complexes is marginal in heme systems in the presence of a strong proximal ligand (His, Cys, or Tyr), and the aqueous solution at a near-neutral pH. The numerous attempts to isolate such complexes obtained in reactions of hydrogen peroxide with P450 at ambient conditions have failed because of the inherent low stability and fast conversion to ferryl-oxo species with 0-0 bond scission There have been successful isolations of the ferriheme-peroxide complex in myoglobin, however . ... 

Fig. 3. Push-pull mechanism for the heterolysis of the 0-0 bond of an iron-peroxo complex. The oval indicates an electron-rich ligand, such as a porphyrin L is a heme-proximal ligand (cysteine or histidine).

Girerd, J. J. Banse, F. Simaan, A. J. Characterization and properties of non-heme iron peroxo complexes. In Metal-Oxo and Metal-Peroxo Species in Catalytic Oxidations Structure Bonding wo. 97, Springer-Verlag, 2000, p. 145. 

The participation of the two mechanisms is indicated by the effect of added dimethyl sulfide. The presence of dimethyl sulfide suppressed formation of cyclohexanol, cyclohexanone and halocyclohexane but did not affect the production of r-butylperoxy-cyclohexane. In place of the former products, dimethyl sulfoxide was found. Since sulfides can act as a trap for a two-electron oxidant such as an iron-peroxo or an iron-oxo species, the formation of alcohol, ketone and haloalkane must involve heterolysis of the alkyl hydroperoxide, i.e. 

Active Iron-Oxo and Iron-Peroxo Species in Cytochromes P450 and Peroxidases Oxo-Hydroxo Tautomerism with Water-Soluble Metalloporphyrins... 

Nucleophilicity of Iron-Peroxo Porphyrin Complexes D.L. Wertz, J.S. Valentine... 

Characterization and Properties of Non-Heme Iron Peroxo Complexes... 

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