High-valent metalloporphyrin

A number of high-valent metalloporphyrin complexes have been reported. Again high-valency is taken relative to normal species. Many of these species are stabilized by the presence of oxygen donors in the form of oxo or alkoxo ligands. One such set is a series of binuclear p-oxo complexes where the metals (Ru, Os, Mn) have the formal oxidation state +4. All complexes of this class are six-coordinate and include [Ru(0EP)(0H)]20 " [Ru(TPP)(0C6H4CH3)]20 ), [Ru(OEP)C1]20 ),... 

J. Bernadou, A. Fabiano, A. Robert, B. Meunier, Redox tautomerism in high-valent metal-oxo-aquo complexes.Origin of the oxygen atom in epoxidation reactions catalyzed by water-soluble metalloporphyrins,/. Am. Chem. Soc. 116 (1994) 9375. 

Warren KD (1977) Ligand Field Theory of f-Orbital Sandwich Complexes. 33 97-137 Warren KD (1976) Ligand Field Theory of Metal Sandwich Complexes. 33 97-137 Watanabe Y, Fujii H (2000) Characterization of High-Valent Oxo-Metalloporphyrins. 97 61-90... 

Watanabe, Y. and H. Fujii (2000). Characterization of high-valent oxo-metalloporphyrins. In B. Meunier (ed.). Structure and Bonding, Vol 97, Springer-Verlag, Berlin, pp. 61-89. 

It has been widely accepted that the high-valent iron oxo complex 1 is the active oxidant in metalloporphyrin systems and in non-porphyrin iron complex systems as well. A high-valent iron oxo species can be formed via heterolytic 0-0 bond cleavage of the iron-hydroperoxide 2 or of the iron-peroxyacid species 4 (Figure 5, pathway A). Recently, elegant proof of this heterolytic 0-0 bond cleavage of hydrogen peroxide, MCPBA, and f-butyl hydroperoxide has been provided by Traylor et al in iron porphyrin... 

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