Crystallographic and spectroscopic characterization of a nonheme Fe(IV)-O complex.

Following the heme paradigm, it is often proposed that dioxygen activation by nonheme monoiron enzymes involves an iron(IV)=oxo intermediate that is responsible for the substrate oxidation step. Such a transient species has now been obtained from a synthetic complex with a nonheme macrocyclic ligand and characterized spectroscopically. Its high-resolution crystal structure reveals an iron-oxygen bond length of 1.646(3) angstroms, demonstrating that a terminal iron(IV)=oxo unit can exist in a nonporphyrin ligand environment and lending credence to proposed mechanisms of nonheme iron catalysis.

[1]  Stephen G. Sligar,et al.  Kinetic Characterization of Compound I Formation in the Thermostable Cytochrome P450 CYP119* , 2002, The Journal of Biological Chemistry.

[2]  S. Lippard,et al.  Functional mimic of dioxygen-activating centers in non-heme diiron enzymes: mechanistic implications of paramagnetic intermediates in the reactions between diiron(II) complexes and dioxygen. , 2002, Journal of the American Chemical Society.

[3]  L. Que,et al.  A synthetic model for the putative Fe(IV)(2)O(2) diamond core of methane monooxygenase intermediate Q. , 2001, Journal of the American Chemical Society.

[4]  Y. Hirano,et al.  Monooxygenation mechanism by cytochrome p-450. , 2001, Journal of the American Chemical Society.

[5]  L. Que,et al.  "Intermolecular" trapping of a nonheme Fe(IV)=O intermediate. , 2001, Inorganic chemistry.

[6]  K Wieghardt,et al.  Mononuclear (nitrido)iron(V) and (oxo)iron(IV) complexes via photolysis of [(cyclam-acetato)FeIII(N3)]+ and ozonolysis of [(cyclam-acetato)FeIII(O3SCF3)]+ in water/acetone mixtures. , 2000, Inorganic chemistry.

[7]  S. Shaik,et al.  A Model “Rebound” Mechanism of Hydroxylation by Cytochrome P450: Stepwise and Effectively Concerted Pathways, and Their Reactivity Patterns , 2000 .

[8]  V. Schünemann,et al.  Intermediates in the reaction of substrate‐free cytochrome P450cam with peroxy acetic acid , 2000, FEBS letters.

[9]  K. Kuczera,et al.  O2 activation by nonheme iron complexes: A monomeric Fe(III)-Oxo complex derived from O2. , 2000, Science.

[10]  Lawrence Que,et al.  The Flexible Fe2(μ-O)2 Diamond Core: A Terminal Iron(IV)−Oxo Species Generated from the Oxidation of a Bis(μ-oxo)diiron(III) Complex , 2000 .

[11]  J Berendzen,et al.  The catalytic pathway of cytochrome p450cam at atomic resolution. , 2000, Science.

[12]  A. Trautwein,et al.  Generation of oxoiron(IV) tetramesitylporphyrin π-cation radical complexes by m-CPBA oxidation of ferric tetramesitylporphyrin derivatives in butyronitrile at −78 °C. Evidence for the formation of six-coordinate oxoiron(IV) tetramesitylporphyrin π-cation radical complexes FeIV=O(tmp)X (X=Cl−, Br−), , 2000 .

[13]  H. Fujii,et al.  Characterization of High-Valent Oxo-Metalloporphyrins , 2000 .

[14]  Mindy I. Davis,et al.  Geometric and electronic structure/function correlations in non-heme iron enzymes. , 2000, Chemical reviews.

[15]  P. Siegbahn,et al.  O-O bond cleavage and alkane hydroxylation in methane monooxygenase , 2000, JBIC Journal of Biological Inorganic Chemistry.

[16]  Djamaladdin G. Musaev,et al.  Mechanism of the methane → methanol conversion reaction catalyzed by methane monooxygenase: A density functional study , 1999 .

[17]  L. Que,et al.  Evidence for a Nonheme Fe(IV)O Species in the Intramolecular Hydroxylation of a Phenyl Moiety , 1999 .

[18]  L. Que,et al.  Crystal structure of a synthetic high-valent complex with an FE2(μ- O)2 diamond core. Implications for the core structures of methane monooxygenase intermediate Q and ribonucleotide reductase intermediate X , 1999 .

[19]  R. Ho,et al.  Dioxygen Activation by Enzymes with Mononuclear Non-Heme Iron Active Sites. , 1996, Chemical reviews.

[20]  J. Dawson,et al.  Heme-Containing Oxygenases. , 1996, Chemical reviews.

[21]  Y. Mizutani,et al.  Resonance Raman spectra of highly oxidized metalloporphyrins and heme proteins , 1994 .

[22]  Brian G. Fox,et al.  High-valent transition metal chemistry. Moessbauer and EPR studies of high-spin (S = 2) iron(IV) and intermediate-spin (S = 3/2) iron(III) complexes with a macrocyclic tetraamido-N ligand , 1993 .

[23]  J. Valentine,et al.  Iron-cyclam complexes as catalysts for the epoxidation of olefins by 30% aqueous hydrogen peroxide in acetonitrile and methanol , 1991 .

[24]  R. Hamlin,et al.  Crystal structure of cytochrome c peroxidase compound I. , 1987, Biochemistry.

[25]  K. Hodgson,et al.  Structural characterization of horseradish peroxidase using EXAFS spectroscopy. Evidence for Fe = O ligation in compounds I and II. , 1986, Journal of the American Chemical Society.

[26]  T. Poulos,et al.  Cytochrome c peroxidase compound ES is identical with horseradish peroxide compound I in iron-ligand distances. , 1986, Biochemistry.

[27]  A. Trautwein,et al.  Formation of an iron(IV)-oxo picket-fencë porphyrin derivative via reduction of the ferrous dioxygen adduct and reaction with carbon dioxide , 1985 .

[28]  R. Murmann,et al.  Structure of dipotassium ferrate(VI) , 1982 .

[29]  A. Balch,et al.  Role of ferryl (FeO2+) complexes in oxygen atom transfer reactions. Mechanism of iron(II) porphyrin catalyzed oxygenation of triphenylphosphine , 1980 .

[30]  W. Oosterhuis,et al.  Magnetic properties of the t2g4 configuration in low symmetry crystal fields , 1973 .