title: An N-bridged high-valent diiron-oxo species on a porphyrin platform that can oxidize methane.
abstract: High-valent oxo-metal complexes are involved in key biochemical processes of selective oxidation and removal of xenobiotics. The catalytic properties of cytochrome P-450 and soluble methane monooxygenase enzymes are associated with oxo species on mononuclear iron haem and diiron non-haem platforms, respectively. Bio-inspired chemical systems that can reproduce the fascinating ability of these enzymes to oxidize the strongest C-H bonds are the focus of intense scrutiny. In this context, the development of highly oxidizing diiron macrocyclic catalysts requires a structural determination of the elusive active species and elucidation of the reaction mechanism. Here we report the preparation of an Fe(IV)(µ-nitrido)Fe(IV) = O tetraphenylporphyrin cation radical species at -90 °C, characterized by ultraviolet-visible, electron paramagnetic resonance and Mössbauer spectroscopies and by electrospray ionization mass spectrometry. This species exhibits a very high activity for oxygen-atom transfer towards alkanes, including methane. These findings provide a foundation on which to develop efficient and clean oxidation processes, in particular transformations of the strongest C-H bonds.
authors.affiliation: Institut de Recherches sur la Catalyse et l'Environnement de Lyon, Unité Mixte de Recherche 5256, Centre National de la Recherche Scientifique, Université Lyon 1, 2 Avenue Albert Einstein, 69626                 Villeurbanne Cedex, France.
authors.forename: Evgeny V
authors.initials: EV
authors.lastname: Kudrik
authors.forename: Pavel
authors.initials: P
authors.lastname: Afanasiev
authors.forename: Leonardo X
authors.initials: LX
authors.lastname: Alvarez
authors.forename: Patrick
authors.initials: P
authors.lastname: Dubourdeaux
authors.forename: Martin
authors.initials: M
authors.lastname: Clémancey
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Latour
authors.forename: Geneviève
authors.initials: G
authors.lastname: Blondin
authors.forename: Denis
authors.initials: D
authors.lastname: Bouchu
authors.forename: Florian
authors.initials: F
authors.lastname: Albrieux
authors.forename: Sergey E
authors.initials: SE
authors.lastname: Nefedov
authors.forename: Alexander B
authors.initials: AB
authors.lastname: Sorokin
mesh_terms: D002723:Chlorobenzoates / Q000737:chemistry; D008665:Metalloporphyrins / Q000737:chemistry*; D008697:Methane / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry*; D010084:Oxidation-Reduction; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D002723:Chlorobenzoates; D008665:Metalloporphyrins; C000433:3-chloroperbenzoic acid; D009584:Nitrogen; D008697:Methane