New Example of a Non-Heme Mononuclear Iron(IV) Oxo Complex. Spectroscopic Data and Oxidation Activity
journal contributionposted on 12.12.2005, 00:00 authored by Marlène Martinho, Frédéric Banse, Jean-François Bartoli, Tony A. Mattioli, Pierrette Battioni, Olivier Horner, Sophie Bourcier, Jean-Jacques Girerd
The green complex S = 1 [(TPEN)FeO]2+ [TPEN = N,N,N‘,N‘-tetrakis(2-pyridylmethyl)ethane-1,2-diamine] has been obtained by treating the [(TPEN)Fe]2+ precursor with meta-chloroperoxybenzoic acid (m-CPBA). This high-valent complex belongs to the emerging family of synthetic models of FeIVO intermediates invoked during the catalytic cycle of biological systems. This complex exhibits spectroscopic characteristics that are similar to those of other models reported recently with a similar amine/pyridine environment. Thanks to its relative stability, vibrational data in solution have been obtained by Fourier transform infrared. A comparison of the FeO and Fe18O wavenumbers reveals that the Fe−oxo vibration is not a pure one. The ability of the green complex to oxidize small organic molecules has been studied. Mixtures of oxygenated products derived from two- or four-electron oxidations are obtained. The reactivity of this [FeO]2+ complex is then not straightforward, and different mechanisms may be involved.