An N-bridged high-valent diiron-oxo species on a porphyrin platform that can oxidize methane

E. V. Kudrik (1) , P. Afanasiev (2) , L. X. Alvarez , P. Dubourdeaux , M. Clemancey , J. M. Latour , G. Blondin , D. Bouchu , F. Albrieux , S. E. Nefedov , A. B. Sorokin (1)

1 BIOVERT - BIOVERT
2 RAFFINAGE - RAFFINAGE

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)(mu-nitrido)Fe(IV) = O tetraphenylporphyrin cation radical species at -90 degrees C, characterized by ultraviolet-visible, electron paramagnetic resonance and Mossbauer 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.

Domaines: Catalyse; Environnement et Société

E. V. Kudrik, P. Afanasiev, L. X. Alvarez, P. Dubourdeaux, M. Clemancey, et al.. An N-bridged high-valent diiron-oxo species on a porphyrin platform that can oxidize methane. Nature Chemistry, 2012, 4, pp.1024-1029. ⟨10.1038/nchem.1471⟩. ⟨hal-00777525⟩