New example of a non-heme mononuclear iron(IV) oxo complex. Spectroscopic data and oxidation activity

Inorg Chem. 2005 Dec 12;44(25):9592-6. doi: 10.1021/ic051213y.

Abstract

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 Fe(IV)=O 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 Fe=O and Fe=(18)O 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.

MeSH terms

  • Ethylamines / chemistry*
  • Iron / chemistry*
  • Ligands
  • Models, Molecular
  • Molecular Structure
  • Organometallic Compounds / chemical synthesis
  • Organometallic Compounds / chemistry*
  • Oxidation-Reduction
  • Oxygen / chemistry*
  • Pyridines
  • Pyrimidines / chemistry*
  • Sensitivity and Specificity
  • Solutions / chemistry
  • Spectrometry, Mass, Electrospray Ionization / methods*
  • Spectroscopy, Fourier Transform Infrared / methods
  • Vibration

Substances

  • Ethylamines
  • Ligands
  • N,N,N',N'-tetrakis(2-pyridylmethyl)ethane-1,2-diamine
  • Organometallic Compounds
  • Pyridines
  • Pyrimidines
  • Solutions
  • Iron
  • Oxygen