The first isolation and spectroscopic characterization of the mononuclear hydroperoxo-iron(III) complex [Fe(H2bppa)(OOH)]2+ (2) and the stoichiometric oxidation of substrates by the mononuclear iron-oxo intermediate generated by its decomposition have been described. The purple species 2 obtained from reaction of [Fe(H2bppa)(HCOO)](CIO4)2 with H2O2 in acetone at -50 °C gave characteristic UV-vis (λmax = 568 nm, ε = 1200 M-1 cm-1), ESR (g = 7.54, 5.78, and 4.25, S = 5/2), and ESI mass spectra (m/z 288.5 corresponding to the ion, [Fe(bppa)(OOH)]2+), which revealed that 2 is a high-spin mononuclear iron(III) complex with a hydroperoxide in an end-on fashion. The resonance Raman spectrum of 2 in d6-acetone revealed two intense bands at 621 and 830 cm-1, which shifted to 599 and 813 cm-1, respectively, when reacted with 18O-labeled H2O2, Reactions of the isolated (bppa)FeIII-OOH (2) with various substrates (single turnover oxidations) exhibited that the iron-oxo intermediate generated by decomposition of 2 is a nucleophilic species formulated as [(H2bppa)FeIII-O•].
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Inorganic Chemistry