Iron(III) complex of a crown ether-porphyrin conjugate and reversible binding of superoxide to its iron(II) form

被引:0
|
作者
Dürr, Katharina [1 ,2 ]
Macpherson, Brendan P. [1 ]
Warratz, Ralf [3 ]
Hampel, Frank [2 ]
Tuczek, Felix [3 ]
Helmreich, Matthias [2 ]
Jux, Norbert [2 ]
Ivanović-Burmazović, Ivana [1 ]
机构
[1] Institute of Inorganic Chemistry, University of Erlangen-Nürnberg, Egerlandstrasse 1, 91058 Erlangen, Germany
[2] Institute of Organic Chemistry, University of Erlangen-Nürnberg, Henkestrasse 42, 91054 Erlangen, Germany
[3] Institute of Inorganic Chemistry, Christian-Albrechts-University Kiel, Otto Hahn Plan 6/7, 24098 Kiel, Germany
来源
关键词
The synthesis and characterization of the Fe(III) complex of a novel crown ether-porphyrin conjugate, 52-N-(4-aza-18-crown-6)methyl-5 4,104,154,204-tetra-tert-butyl- 56-methyl-5,10,15,20-tetraphenylporphyrin (H2Porph), as well as the corresponding hydroxo, dimeric, Fe(II), and peroxo species are reported. The crystal structure of [FeIII(Porph)Cl]&middotH 3O+&middotFeCl4-&middotC 6H6&middotEtOH is also reported. [FeIII(Porph) (DMSO)2]+ and K[FeIII(Porph)(O2 2-)] are high-spin species (Mössbauer data: δ = 0.38 mm s-1, ΔEq = 0.83 mm s-1 and δ = 0.41 mm s-1, ΔEq = 0.51 mm s-1, respectively), whereas in a solution of reduced [FeIII(Porph)-(DMSO) 2]+ complex the low-spin [FeII(Porph)(DMSO) 2] (δ = 0.44 mm s-1, ΔEq = 1.32 mm s-1) and high-spin [FeII(Porph)(DMSO)] (δ = 1.27 mm s-1 ΔEq = 3.13 mm s-1) iron(II) species are observed. The reaction of [FeIII(Porph)(DMSO)2] + with KO2 in DMSO has been investigated. The first reaction step, involving reduction to [FeII(Porph)(DMSO) 2], was not investigated in detail because of parallel formation of an Fe-(III)-hydroxo species. The kinetics and thermodynamics of the second reaction step, reversible binding of superoxide to the Fe(II) complex and formation of an Fe(III)-peroxo species, were studied in detail (by stopped-flow time-resolved UV/vis measurements in DMSO at 25°C), resulting in k on = 36 500 ± 500 M-1 s-1, k off = 0.21 ± 0.01 s-1 (direct measurements using an acid as a superoxide scavenger), and KO2- = (1.7 ± 0.2) × 105 (superoxide binding constant kinetically obtained as kon/koff), (1.4 ± 0.1) × 105, and (9.0 ± 0.1) × 104 M-1 (thermodynamically obtained in the absence and in the presence of 0.1 M NBu4PF 6, respectively). Temperature-dependent kinetic measurements for kon (-40 to 25°C in 3:7 DMSO/CH3CN mixture) yielded the activation parameters ΔH‡ = 61.2 ± 0.9 kJ mol-1 and ΔS‡ = +48 ± 3 J K -1 mol-1. The observed reversible binding of superoxide to the metal center and the obtained kinetic and thermodynamic parameters are unique. The finding that fine-tuning of the proton concentration can cause the Fe(III)-peroxo species to release O2- and form an Fe(II) species is of biological interest, since this process might occur under very specific physiological conditions. © 2007 American Chemical Society;
D O I
暂无
中图分类号
学科分类号
摘要
Journal article (JA)
引用
收藏
页码:4217 / 4228
相关论文
共 50 条
  • [1] Iron(III) complex of a crown ether-porphyrin conjugate and reversible binding of superoxide to its Iron(II) form
    Duerr, Katharina
    Macpherson, Brendan P.
    Warratz, Ralf
    Hampel, Frank
    Tuczek, Felix
    Helmreich, Matthias
    Jux, Norbert
    Ivanovic-Burmazovic, Ivana
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2007, 129 (14) : 4217 - 4228
  • [2] Volume Profile Analysis for the Reversible Binding of Superoxide to Form Iron(II)-Superoxo/Iron(III)-Peroxo Porphyrin Complexes
    Duerr, Katharine
    Jux, Norbert
    Zahl, Achim
    van Eldik, Rudi
    Ivanovic-Burmazovic, Ivana
    INORGANIC CHEMISTRY, 2010, 49 (23) : 11254 - 11260
  • [3] Investigation of iron(III) complex with crown-porphyrin
    Pankratov, Denis A. (pankratov@radio.chem.msu.ru), 1600, Kluwer Academic Publishers (222):
  • [4] Investigation of iron(III) complex with crown-porphyrin
    Denis A. Pankratov
    Vladimir D. Dolzhenko
    Reonald A. Stukan
    Yana F. Al Ansari
    Elena V. Savinkina
    Yury M. Kiselev
    Hyperfine Interactions, 2013, 222 : 1 - 11
  • [5] Investigation of iron(III) complex with crown-porphyrin
    Pankratov, Denis A.
    Dolzhenko, Vladimir D.
    Stukan, Reonald A.
    Al Ansari, Yana F.
    Savinkina, Elena V.
    Kiselev, Yury M.
    HYPERFINE INTERACTIONS, 2013, 222 : S1 - S11
  • [6] Investigation of iron(III) complex with crown-porphyrin
    Pankratov, D. A. (pankratov@radio.chem.msu.ru), 1600, Kluwer Academic Publishers (222):
  • [7] Mossbauer spectroscopic study of an iron(III) complex with crown porphyrin
    Pankratov, D. A.
    Stukan, R. A.
    Al' Ansari, Ya. -F.
    Savinkina, E. V.
    Kiselev, Yu. M.
    RUSSIAN JOURNAL OF INORGANIC CHEMISTRY, 2011, 56 (10) : 1603 - 1608
  • [8] REVERSIBLE OXYGENATION AND AUTOXIDATION OF A CAPPED PORPHYRIN IRON(II) COMPLEX
    ALMOG, J
    BALDWIN, JE
    HUFF, J
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1975, 97 (01) : 227 - 228
  • [9] Mössbauer spectroscopic study of an iron(III) complex with crown porphyrin
    D. A. Pankratov
    R. A. Stukan
    Ya. -F. Al’ Ansari
    E. V. Savinkina
    Yu. M. Kiselev
    Russian Journal of Inorganic Chemistry, 2011, 56 : 1603 - 1608
  • [10] Spontaneous reduction of iron(iii)porphyrin to iron(ii)porphyrin-CO complex in mouse circulation
    Noguchi, Masataka
    Mao, Qiyue
    Nakagami, Atsuki
    Kitagishi, Hiroaki
    CHEMICAL COMMUNICATIONS, 2023, 59 (41) : 6211 - 6214