1
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Zars E, Gravogl L, Gau MR, Carroll PJ, Meyer K, Mindiola DJ. Isostructural bridging diferrous chalcogenide cores [Fe II(μ-E)Fe II] (E = O, S, Se, Te) with decreasing antiferromagnetic coupling down the chalcogenide series. Chem Sci 2023; 14:6770-6779. [PMID: 37350823 PMCID: PMC10283490 DOI: 10.1039/d3sc01094e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/24/2023] [Indexed: 06/24/2023] Open
Abstract
Iron compounds containing a bridging oxo or sulfido moiety are ubiquitous in biological systems, but substitution with the heavier chalcogenides selenium and tellurium, however, is much rarer, with only a few examples reported to date. Here we show that treatment of the ferrous starting material [(tBupyrpyrr2)Fe(OEt2)] (1-OEt2) (tBupyrpyrr2 = 3,5-tBu2-bis(pyrrolyl)pyridine) with phosphine chalcogenide reagents E = PR3 results in the neutral phosphine chalcogenide adduct series [(tBupyrpyrr2)Fe(EPR3)] (E = O, S, Se; R = Ph; E = Te; R = tBu) (1-E) without any electron transfer, whereas treatment of the anionic starting material [K]2[(tBupyrpyrr2)Fe2(μ-N2)] (2-N2) with the appropriate chalcogenide transfer source yields cleanly the isostructural ferrous bridging mono-chalcogenide ate complexes [K]2[(tBupyrpyrr2)Fe2(μ-E)] (2-E) (E = O, S, Se, and Te) having significant deviation in the Fe-E-Fe bridge from linear in the case of E = O to more acute for the heaviest chalcogenide. All bridging chalcogenide complexes were analyzed using a variety of spectroscopic techniques, including 1H NMR, UV-Vis electronic absorbtion, and 57Fe Mössbauer. The spin-state and degree of communication between the two ferrous ions were probed via SQUID magnetometry, where it was found that all iron centers were high-spin (S = 2) FeII, with magnetic exchange coupling between the FeII ions. Magnetic studies established that antiferromagnetic coupling between the ferrous ions decreases as the identity of the chalcogen is tuned from O to the heaviest congener Te.
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Affiliation(s)
- Ethan Zars
- Department of Chemistry, University of Pennsylvania 231 S 34th St Philadelphia PA 19104 USA
| | - Lisa Gravogl
- Department of Chemistry & Pharmacy, Friedrich-Alexander-Universität Erlangen - Nürnberg (FAU) Egerlandstr. 1 91058 Erlangen Bavaria Germany
| | - Michael R Gau
- Department of Chemistry, University of Pennsylvania 231 S 34th St Philadelphia PA 19104 USA
| | - Patrick J Carroll
- Department of Chemistry, University of Pennsylvania 231 S 34th St Philadelphia PA 19104 USA
| | - Karsten Meyer
- Department of Chemistry & Pharmacy, Friedrich-Alexander-Universität Erlangen - Nürnberg (FAU) Egerlandstr. 1 91058 Erlangen Bavaria Germany
| | - Daniel J Mindiola
- Department of Chemistry, University of Pennsylvania 231 S 34th St Philadelphia PA 19104 USA
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2
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Balamurugan M, Suresh E, Palaniandavar M. μ-Oxo-bridged diiron(iii) complexes of tripodal 4N ligands as catalysts for alkane hydroxylation reaction using m-CPBA as an oxidant: substrate vs. self hydroxylation. RSC Adv 2021; 11:21514-21526. [PMID: 35478792 PMCID: PMC9034113 DOI: 10.1039/d1ra03135j] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 05/28/2021] [Indexed: 11/23/2022] Open
Abstract
A series of non-heme μ-oxo-bridged dinuclear iron(iii) complexes of the type [Fe2(μ-O)(L1–L6)2Cl2]Cl21–6 have been isolated and their catalytic activity towards oxidative transformation of alkanes into alcohols has been studied using m-choloroperbenzoic acid (m-CPBA) as an oxidant. All the complexes were characterized by CHN, electrochemical, and UV-visible spectroscopic techniques. The molecular structures of 2 and 5 have been determined successfully by single crystal X-ray diffraction analysis and both possesses octahedral coordination geometry and each iron atom is coordinated by four nitrogen atoms of the 4N ligand and a bridging oxygen. The sixth position of each octahedron is coordinated by a chloride ion. The (μ-oxo)diiron(iii) core is linear in 2 (Fe–O–Fe, 180.0°), whereas it is non-linear (Fe–O–Fe, 161°) in 5. All the diiron(iii) complexes show quasi-reversible one electron transfer in the cyclic voltammagram and catalyze the hydroxylation of alkanes like cyclohexane, adamantane with m-CPBA as an oxidant. In acetonitrile solution, adding excess m-CPBA to the diiron(iii) complex 2 without chloride ions leads to intramolecular hydroxylation reaction of the oxidant. Interestingly, 2 catalyzes alkane hydroxylation in the presence of chloride ions, but intramolecular hydroxylation in the absence of chloride ions. The observed selectivity for cyclohexane (A/K, 5–7) and adamantane (3°/2°, 9–18) suggests the involvement of high-valent iron–oxo species rather than freely diffusing radicals in the catalytic reaction. Moreover, 4 oxidizes (A/K, 7) cyclohexane very efficiently up to 513 TON while 5 oxidizes adamantane with good selectivity (3°/2°, 18) using m-CPBA as an oxidant. The electronic effects of ligand donors dictate the efficiency and selectivity of catalytic hydroxylation of alkanes. The ligand stereoelectronic effect of diiron(iii) complexes determines the efficiency and selectivity of catalytic alkane hydroxylation with m-CPBA as an oxidant.![]()
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Affiliation(s)
- Mani Balamurugan
- School of Chemistry, Bharathidasan University Tiruchirappalli 620 024 Tamil Nadu India
| | - Eringathodi Suresh
- Analytical Science Discipline, Central Salt and Marine Chemicals Research Institute Bhavnagar 364 002 India
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3
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Battistella B, Heims F, Cula B, Ray K. Synthesis, Characterization, and Reactivity of a Series of Homo‐ and Hetero‐dinuclear Complexes based on an Asymmetric FloH Ligand System. Z Anorg Allg Chem 2020. [DOI: 10.1002/zaac.202000221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Beatrice Battistella
- Institut für Chemie Humboldt‐Universität zu Berlin Brook‐Taylor Str. 2 12489 Berlin Germany
| | - Florian Heims
- Institut für Chemie Humboldt‐Universität zu Berlin Brook‐Taylor Str. 2 12489 Berlin Germany
| | - Beatrice Cula
- Institut für Chemie Humboldt‐Universität zu Berlin Brook‐Taylor Str. 2 12489 Berlin Germany
| | - Kallol Ray
- Institut für Chemie Humboldt‐Universität zu Berlin Brook‐Taylor Str. 2 12489 Berlin Germany
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4
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Trehoux A, Guillot R, Clemancey M, Blondin G, Latour JM, Mahy JP, Avenier F. Bioinspired symmetrical and unsymmetrical diiron complexes for selective oxidation catalysis with hydrogen peroxide. Dalton Trans 2020; 49:16657-16661. [DOI: 10.1039/d0dt03308a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Two new symmetrical and unsymmetrical diiron(iii) complexes were synthesized and characterized by X-ray diffraction analysis, mass spectrometry, UV-visible and Mössbauer spectroscopies. They were then used for selective oxidation catalysis.
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Affiliation(s)
- Alexandre Trehoux
- Université Paris-Saclay
- CNRS
- Institut de Chimie Moléculaire et des Matériaux d'Orsay
- Equipe de Chimie Bioorganique et Bioinorganique
- 91405 Orsay
| | - Régis Guillot
- Université Paris-Saclay
- CNRS
- Institut de Chimie Moléculaire et des Matériaux d'Orsay
- Equipe de Chimie Bioorganique et Bioinorganique
- 91405 Orsay
| | | | | | | | - Jean-Pierre Mahy
- Université Paris-Saclay
- CNRS
- Institut de Chimie Moléculaire et des Matériaux d'Orsay
- Equipe de Chimie Bioorganique et Bioinorganique
- 91405 Orsay
| | - Frédéric Avenier
- Université Paris-Saclay
- CNRS
- Institut de Chimie Moléculaire et des Matériaux d'Orsay
- Equipe de Chimie Bioorganique et Bioinorganique
- 91405 Orsay
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5
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Sekino M, Furutachi H, Tasaki K, Ishikawa T, Mori S, Fujinami S, Akine S, Sakata Y, Nomura T, Ogura T, Kitagawa T, Suzuki M. New mechanistic insight into intramolecular arene hydroxylation initiated by (μ-1,2-peroxo)diiron(III) complexes with dinucleating ligands. Dalton Trans 2016; 45:469-73. [PMID: 26646073 DOI: 10.1039/c5dt04088d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
(μ-1,2-Peroxo)diiron(iii) complexes (-R) with dinucleating ligands (R-L) generated from the reaction of bis(μ-hydroxo)diiron(ii) complexes [Fe2(R-L)(OH)2](2+) (-R) with dioxygen in acetone at -20 °C provide a diiron-centred electrophilic oxidant, presumably diiron(iv)-oxo species, which is involved in aromatic ligand hydroxylation.
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Affiliation(s)
- Mio Sekino
- Department of Chemistry, Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
| | - Hideki Furutachi
- Department of Chemistry, Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
| | - Kyosuke Tasaki
- Department of Chemistry, Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
| | - Takanao Ishikawa
- Department of Chemistry, Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
| | - Shigeki Mori
- Department of Chemistry, Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
| | - Shuhei Fujinami
- Department of Chemistry, Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
| | - Shigehisa Akine
- Department of Chemistry, Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
| | - Yoko Sakata
- Department of Chemistry, Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
| | - Takashi Nomura
- Picobiology Institute, Graduate School of Life Science, University of Hyogo, Ako-gun, Hyogo 678-1297, Japan
| | - Takashi Ogura
- Picobiology Institute, Graduate School of Life Science, University of Hyogo, Ako-gun, Hyogo 678-1297, Japan
| | - Teizo Kitagawa
- Picobiology Institute, Graduate School of Life Science, University of Hyogo, Ako-gun, Hyogo 678-1297, Japan
| | - Masatatsu Suzuki
- Department of Chemistry and Biochemistry, Graduate Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan
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6
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Kuźnik N, Chmielniak U. Studies on the redox activity of iron N,O-complexes: Potential T 1-contrast agents. Redox Rep 2016; 21:37-44. [PMID: 26023764 PMCID: PMC6837439 DOI: 10.1179/1351000215y.0000000017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
OBJECTIVES The goal of this study was to determine the redox activity of iron (ethylenebis[2-(o-hydroxyphenyl)glycine]) (EHPG) and (ethylenebis[2-(o-hydroxybenzyl)glycine]) (EHBG) (N,N'-bis(2-hydroxybenzyl)ethylenediamine-N,N'-diacetic acid) derivative complexes and of some N,O-salan complexes of iron. The hexadentate chelate (EHPG and EHBG) ligands varied in their substituents (polar OMe, NHAc, or lipophilic Ph), while the latter had different charge and lipophilicity. The low redox activity of these complexes is important in their potential applications as magnetic resonance imaging contrast agents. METHODS Redox activity was assessed in the entire Haber-Weiss cycle and separately in the Fenton reaction. The spin-trapping method with 5,5-dimethyl-1-pyrroline-N-oxide monitored in electron paramagnetic resonance was used. The standard Mn marker was applied as a reference for quantitative analysis. Additionally, ascorbate oxidation was analyzed with UV-Vis spectrophotometry. RESULTS Both the Haber-Weiss cycle and in particular the Fenton reaction showed low redox activity of the studied complexes, which did not exceed 30% of [Fe(EDTA)]- or FeCl3 activity. The N,O-salan complexes expressed even lower activity, i.e. 10-20% activity of [Fe(EDTA)]-. DISCUSSION For the EHPG and EHBG complexes, it is likely that hydrophobicity and the possibility of H-bond formation play a major role in the resulting redox effects. For this reason, chelates equipped with phenyl groups in the majority belong to less redox-active complexes. For N,O-salan complexes, activity is not correlated with the charge of the coordination sphere, but again, the highly hydrophobic character of the groups and the non-pendant substituents capable of H-bonding that are present in these ligands limit the affinity of hydrophilic species.
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Affiliation(s)
- Nikodem Kuźnik
- Faculty of Chemistry, Silesian University of
Technology, M. Strzody 9, 44-100 Gliwice,
Poland
| | - Urszula Chmielniak
- Faculty of Chemistry, Silesian University of
Technology, M. Strzody 9, 44-100 Gliwice,
Poland
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7
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Balamurugan M, Suresh E, Palaniandavar M. Non-heme μ-Oxo- and bis(μ-carboxylato)-bridged diiron(iii) complexes of a 3N ligand as catalysts for alkane hydroxylation: stereoelectronic factors of carboxylate bridges determine the catalytic efficiency. Dalton Trans 2016; 45:11422-36. [DOI: 10.1039/c6dt01059h] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The stereoelectronic factors of carboxylate bridges in diiron(iii) complexes determine the efficiency of catalytic alkane hydroxylation with m-CPBA.
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Affiliation(s)
- Mani Balamurugan
- School of Chemistry
- Bharathidasan University
- Tiruchirappalli - 620024
- India
| | - Eringathodi Suresh
- Analytical Science Discipline
- Central Salt and Marine Chemicals Research Institute
- Bhavnagar - 364 002
- India
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8
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Strautmann JBH, Dammers S, Limpke T, Parthier J, Zimmermann TP, Walleck S, Heinze-Brückner G, Stammler A, Bögge H, Glaser T. Design and synthesis of a dinucleating ligand system with varying terminal donor functions that provides no bridging donor and its application to the synthesis of a series of FeIII–μ-O–FeIII complexes. Dalton Trans 2016; 45:3340-61. [DOI: 10.1039/c5dt03711e] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have developed the dinucleating ligands H4julia, susan, and H4hildeMe2 and present their μ-oxo diferric complexes.
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Affiliation(s)
| | - Susanne Dammers
- Lehrstuhl für Anorganische Chemie I
- Fakultät für Chemie
- Universität Bielefeld
- D-33615 Bielefeld
- Germany
| | - Thomas Limpke
- Lehrstuhl für Anorganische Chemie I
- Fakultät für Chemie
- Universität Bielefeld
- D-33615 Bielefeld
- Germany
| | - Janine Parthier
- Lehrstuhl für Anorganische Chemie I
- Fakultät für Chemie
- Universität Bielefeld
- D-33615 Bielefeld
- Germany
| | | | - Stephan Walleck
- Lehrstuhl für Anorganische Chemie I
- Fakultät für Chemie
- Universität Bielefeld
- D-33615 Bielefeld
- Germany
| | - Gabriele Heinze-Brückner
- Lehrstuhl für Anorganische Chemie I
- Fakultät für Chemie
- Universität Bielefeld
- D-33615 Bielefeld
- Germany
| | - Anja Stammler
- Lehrstuhl für Anorganische Chemie I
- Fakultät für Chemie
- Universität Bielefeld
- D-33615 Bielefeld
- Germany
| | - Hartmut Bögge
- Lehrstuhl für Anorganische Chemie I
- Fakultät für Chemie
- Universität Bielefeld
- D-33615 Bielefeld
- Germany
| | - Thorsten Glaser
- Lehrstuhl für Anorganische Chemie I
- Fakultät für Chemie
- Universität Bielefeld
- D-33615 Bielefeld
- Germany
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9
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Kuźnik N, Wyskocka M. Iron(III) Contrast Agent Candidates for MRI: a Survey of the Structure-Effect Relationship in the Last 15 Years of Studies. Eur J Inorg Chem 2015. [DOI: 10.1002/ejic.201501166] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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10
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Marchi-Delapierre C, Rondot L, Cavazza C, Ménage S. Oxidation Catalysis by Rationally Designed Artificial Metalloenzymes. Isr J Chem 2014. [DOI: 10.1002/ijch.201400110] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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11
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Sankaralingam M, Palaniandavar M. Diiron(III) complexes of tridentate 3N ligands as functional models for methane monooxygenases: Effect of the capping ligand on hydroxylation of alkanes. Polyhedron 2014. [DOI: 10.1016/j.poly.2013.08.067] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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12
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Sahu S, Widger LR, Quesne MG, de Visser SP, Matsumura H, Moënne-Loccoz P, Siegler MA, Goldberg DP. Secondary coordination sphere influence on the reactivity of nonheme iron(II) complexes: an experimental and DFT approach. J Am Chem Soc 2013; 135:10590-3. [PMID: 23834409 PMCID: PMC3746373 DOI: 10.1021/ja402688t] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Indexed: 11/29/2022]
Abstract
The new biomimetic ligands N4Py(2Ph) (1) and N4Py(2Ph,amide) (2) were synthesized and yield the iron(II) complexes [Fe(II)(N4Py(2Ph))(NCCH3)](BF4)2 (3) and [Fe(II)(N4Py(2Ph,amide))](BF4)2 (5). Controlled orientation of the Ph substituents in 3 leads to facile triplet spin reactivity for a putative Fe(IV)(O) intermediate, resulting in rapid arene hydroxylation. Addition of a peripheral amide substituent within hydrogen-bond distance of the iron first coordination sphere leads to stabilization of a high-spin Fe(III)OOR species which decays without arene hydroxylation. These results provide new insights regarding the impact of secondary coordination sphere effects at nonheme iron centers.
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Affiliation(s)
- Sumit Sahu
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Leland R. Widger
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Matthew G. Quesne
- Manchester Institute of Biotechnology
and School of Chemical Engineering and Analytical Science, The University of Manchester, 131 Princess Street,
Manchester M1 7DN, United Kingdom
| | - Sam P. de Visser
- Manchester Institute of Biotechnology
and School of Chemical Engineering and Analytical Science, The University of Manchester, 131 Princess Street,
Manchester M1 7DN, United Kingdom
| | - Hirotoshi Matsumura
- Division of Environmental and Biomolecular Systems, Institute of
Environmental Health, Oregon Health & Science University, Beaverton, Oregon 97006, United States
| | - Pierre Moënne-Loccoz
- Division of Environmental and Biomolecular Systems, Institute of
Environmental Health, Oregon Health & Science University, Beaverton, Oregon 97006, United States
| | - Maxime A. Siegler
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - David P. Goldberg
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
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13
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Ansari A, Kaushik A, Rajaraman G. Mechanistic Insights on the ortho-Hydroxylation of Aromatic Compounds by Non-heme Iron Complex: A Computational Case Study on the Comparative Oxidative Ability of Ferric-Hydroperoxo and High-Valent FeIV═O and FeV═O Intermediates. J Am Chem Soc 2013; 135:4235-49. [DOI: 10.1021/ja307077f] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Azaj Ansari
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Abhishek Kaushik
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India
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14
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Affiliation(s)
- Graham E. O'Mahony
- a Department of Chemistry, Analytical and Biological Chemistry Research Facility , University College Cork , Cork , Ireland
| | - Alan Ford
- a Department of Chemistry, Analytical and Biological Chemistry Research Facility , University College Cork , Cork , Ireland
| | - Anita R. Maguire
- b Department of Chemistry and School of Pharmacy, Analytical and Biological Chemistry Research Facility , University College Cork , Cork , Ireland
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15
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Boros E, Ferreira CL, Patrick BO, Adam MJ, Orvig C. New Ga derivatives of the H2dedpa scaffold with improved clearance and persistent heart uptake. Nucl Med Biol 2011; 38:1165-74. [DOI: 10.1016/j.nucmedbio.2011.05.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2011] [Revised: 04/26/2011] [Accepted: 05/07/2011] [Indexed: 10/17/2022]
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16
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Xue G, Pokutsa A, Que L. Substrate-triggered activation of a synthetic [Fe2(μ-O)2] diamond core for C-H bond cleavage. J Am Chem Soc 2011; 133:16657-67. [PMID: 21899336 DOI: 10.1021/ja207131g] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
An [Fe(IV)(2)(μ-O)(2)] diamond core structure has been postulated for intermediate Q of soluble methane monooxygenase (sMMO-Q), the oxidant responsible for cleaving the strong C-H bond of methane and its hydroxylation. By extension, analogous species may be involved in the mechanisms of related diiron hydroxylases and desaturases. Because of the paucity of well-defined synthetic examples, there are few, if any, mechanistic studies on the oxidation of hydrocarbon substrates by complexes with high-valent [Fe(2)(μ-O)(2)] cores. We report here that water or alcohol substrates can activate synthetic [Fe(III)Fe(IV)(μ-O)(2)] complexes supported by tetradentate tris(pyridyl-2-methyl)amine ligands (1 and 2) by several orders of magnitude for C-H bond oxidation. On the basis of detailed kinetic studies, it is postulated that the activation results from Lewis base attack on the [Fe(III)Fe(IV)(μ-O)(2)] core, resulting in the formation of a more reactive species with a [X-Fe(III)-O-Fe(IV)═O] ring-opened structure (1-X, 2-X, X = OH(-) or OR(-)). Treatment of 2 with methoxide at -80 °C forms the 2-methoxide adduct in high yield, which is characterized by an S = 1/2 EPR signal indicative of an antiferromagnetically coupled [S = 5/2 Fe(III)/S = 2 Fe(IV)] pair. Even at this low temperature, the complex undergoes facile intramolecular C-H bond cleavage to generate formaldehyde, showing that the terminal high-spin Fe(IV)═O unit is capable of oxidizing a C-H bond as strong as 96 kcal mol(-1). This intramolecular oxidation of the methoxide ligand can in fact be competitive with intermolecular oxidation of triphenylmethane, which has a much weaker C-H bond (D(C-H) 81 kcal mol(-1)). The activation of the [Fe(III)Fe(IV)(μ-O)(2)] core is dramatically illustrated by the oxidation of 9,10-dihydroanthracene by 2-methoxide, which has a second-order rate constant that is 3.6 × 10(7)-fold larger than that for the parent diamond core complex 2. These observations provide strong support for the DFT-based notion that an S = 2 Fe(IV)═O unit is much more reactive at H-atom abstraction than its S = 1 counterpart and suggest that core isomerization could be a viable strategy for the [Fe(IV)(2)(μ-O)(2)] diamond core of sMMO-Q to selectively attack the strong C-H bond of methane in the presence of weaker C-H bonds of amino acid residues that define the diiron active site pocket.
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Affiliation(s)
- Genqiang Xue
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, USA
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17
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Aqua bridge cleavage and metal ion extrusion by thiocyanate anions in a dicopper complex. Inorganica Chim Acta 2011. [DOI: 10.1016/j.ica.2011.01.026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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18
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Pygmalion MJ, Ruiz L, Popovic E, Gizard J, Portes P, Marat X, Lucet-Levannier K, Muller B, Galey JB. Skin cell protection against UVA by Sideroxyl, a new antioxidant complementary to sunscreens. Free Radic Biol Med 2010; 49:1629-37. [PMID: 20826208 DOI: 10.1016/j.freeradbiomed.2010.08.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Revised: 08/02/2010] [Accepted: 08/05/2010] [Indexed: 01/17/2023]
Abstract
Oxidative stress resulting from photosensitized ROS production in skin is widely accepted as the main contributor to the deleterious effects of UVA exposure. Among the mechanisms known to be involved in UVA-induced oxidative damage, iron plays a central role. UVA radiation of skin cells induces an immediate release of iron, which can then act as a catalyst for uncontrolled oxidation reactions of cell components. Such site-specific damage can scarcely be counteracted by classical antioxidants. In contrast, iron chelators potentially offer an effective way to protect skin against UVA insults. However, iron chelation is very difficult to achieve without disturbing iron homeostasis or inducing iron depletion. A novel compound was developed to avoid these potentially harmful side effects. Sideroxyl was designed to acquire its strong chelating capability only during oxidative stress according to an original process of intramolecular hydroxylation. Herein, we describe in vitro results demonstrating the protective efficiency of Sideroxyl against deleterious effects of UVA at the molecular, cellular, and tissular levels. First, the Sideroxyl diacid form protects a model protein against UVA-induced photosensitized carbonylation. Second, intracellular ROS are dose-dependently decreased in the presence of Sideroxyl in both human cultured fibroblasts and human keratinocytes. Third, Sideroxyl protects normal human fibroblasts against UVA-induced DNA damage as measured by the comet assay and MMP-1 production. Finally, Sideroxyl provides protection against UVA-induced alterations in human reconstructed skin. These results suggest that Sideroxyl may prevent UVA-induced damage in human skin as a complement to sunscreens, especially in the long-wavelength UVA range.
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Crystallographic snapshots of the reaction of aromatic C-H with O(2) catalysed by a protein-bound iron complex. Nat Chem 2010; 2:1069-76. [PMID: 21107372 DOI: 10.1038/nchem.841] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2010] [Accepted: 08/16/2010] [Indexed: 01/10/2023]
Abstract
Chemical reactions inside single crystals are quite rare because crystallinity is difficult to retain owing to atomic rearrangements. Protein crystals in general have a high solvent content. This allows for some molecular flexibility, which makes it possible to trap reaction intermediates of enzymatic reactions without disrupting the crystal lattice. A similar approach has not yet been fully implemented in the field of inorganic chemistry. Here, we have combined model chemistry and protein X-ray crystallography to study the intramolecular aromatic dihydroxylation by an arene-containing protein-bound iron complex. The bound complex was able to activate dioxygen in the presence of a reductant, leading to the formation of catechol as the sole product. The structure determination of four of the catalytic cycle intermediates and the end product showed that the hydroxylation reaction implicates an iron peroxo, generated by reductive O(2) activation, an intermediate already observed in iron monooxygenases. This strategy also provided unexpected mechanistic details such as the rearrangement of the iron coordination sphere on metal reduction.
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Alonso D, Nájera C, Pastor I, Yus M. Transition-Metal-Catalyzed Synthesis of Hydroxylated Arenes. Chemistry 2010; 16:5274-84. [DOI: 10.1002/chem.201000470] [Citation(s) in RCA: 160] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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21
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Makhlynets OV, Das P, Taktak S, Flook M, Mas-Ballesté R, Rybak-Akimova EV, Que L. Iron-promoted ortho- and/or ipso-hydroxylation of benzoic acids with H(2)O(2). Chemistry 2010; 15:13171-80. [PMID: 19876966 DOI: 10.1002/chem.200901296] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Regioselective hydroxylation of aromatic acids with hydrogen peroxide proceeds readily in the presence of iron(II) complexes with tetradentate aminopyridine ligands [Fe(II)(BPMEN)(CH(3)CN)(2)](ClO(4))(2) (1) and [Fe(II)(TPA)(CH(3)CN)(2)](OTf)(2) (2), where BPMEN=N,N'-dimethyl-N,N'-bis(2-pyridylmethyl)-1,2-ethylenediamine, TPA=tris-(2-pyridylmethyl)amine. Two cis-sites, which are occupied by labile acetonitrile molecules in 1 and 2, are available for coordination of H(2)O(2) and substituted benzoic acids. The hydroxylation of the aromatic ring occurs exclusively in the vicinity of the anchoring carboxylate functional group: ortho-hydroxylation affords salicylates, whereas ipso-hydroxylation with concomitant decarboxylation yields phenolates. The outcome of the substituent-directed hydroxylation depends on the electronic properties and the position of substituents in the molecules of substrates: 3-substituted benzoic acids are preferentially ortho-hydroxylated, whereas 2- and, to a lesser extent, 4-substituted substrates tend to undergo ipso-hydroxylation/decarboxylation. These two pathways are not mutually exclusive and likely proceed via a common intermediate. Electron-withdrawing substituents on the aromatic ring of the carboxylic acids disfavor hydroxylation, indicating an electrophilic nature for the active oxidant. Complexes 1 and 2 exhibit similar reactivity patterns, but 1 generates a more powerful oxidant than 2. Spectroscopic and labeling studies exclude acylperoxoiron(III) and Fe(IV)=O species as potential reaction intermediates, but strongly indicate the involvement of an Fe(III)--OOH intermediate that undergoes intramolecular acid-promoted heterolytic O-O bond cleavage, producing a transient iron(V) oxidant.
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Affiliation(s)
- Olga V Makhlynets
- Department of Chemistry, Tufts University, 62 Talbot Ave., Medford, MA 02155, USA
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22
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Becker JM, Barker J, Clarkson GJ, van Gorkum R, Johal GK, Walton RI, Scott P. Chirality and diastereoselection in the μ-oxo diiron complexes L2Fe–O–FeL2 (L = bidentate salicylaldiminato). Dalton Trans 2010; 39:2309-26. [DOI: 10.1039/b905706d] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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23
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Zhou A, Bao X, Tong M. New twisted-saddle dodecanuclear iron(III) clusters with adamantane-like [Fe4O6] core. ACTA ACUST UNITED AC 2009. [DOI: 10.1007/s11458-009-0098-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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24
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Friedle S, Lippard SJ. Synthesis, Characterization, and Oxygenation Studies of Carboxylate-Bridged Diiron(II) Complexes with Aromatic Substrates Tethered to Pyridine Ligands and the Formation of a Unique Trinuclear Complex. Eur J Inorg Chem 2009; 2009:5506-5515. [PMID: 20376288 DOI: 10.1002/ejic.200900821] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In this study, diiron(II) complexes were synthesized as small molecule mimics of the reduced active sites in the hydroxylase components of bacterial multicomponent monooxygenases (BMMs). Tethered aromatic substrates were introduced in the form of 2-phenoxypyridines, incorporating hydroxy and methoxy functionalities into windmill-type diiron(II) compounds [Fe(2)(μ-O(2)CAr(R))(2)-(O(2)CAr(R))(2)(L)(2)] (1-4), where (-)O(2)CAr(R) is a sterically encumbering carboxylate, 2,6-di(4-fluorophenyl)- or 2,6-di(p-tolyl)benzoate (R = 4-FPh or Tol, respectively). The inability of 1-4 to hydroxylate the aromatic substrates was ascertained. Upon reaction with dioxygen, compounds 2 and 3 (L = 2-(m-MeOPhO)Py, 2-(p-MeOPhO)Py, respectively) decompose by a known bimolecular pathway to form mixed-valent diiron(II,III) species at low temperature. Use of 2-(pyridin-2-yloxy)phenol as the ligand L resulted in a doubly-bridged diiron complex (4) and an unprecedented phenoxide-bridged triiron(II) complex (5) under slightly modified reaction conditions.
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Affiliation(s)
- Simone Friedle
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
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25
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Siewert I, Limberg C. Low-Molecular-Weight Analogues of the Soluble Methane Monooxygenase (sMMO): From the Structural Mimicking of Resting States and Intermediates to Functional Models. Chemistry 2009; 15:10316-28. [DOI: 10.1002/chem.200901910] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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26
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Benhamou L, Machkour A, Rotthaus O, Lachkar M, Welter R, Mandon D. Regiospecific Intramolecular O-Demethylation of the Ligand by Action of Molecular Dioxygen on a Ferrous Complex: Versatile Coordination Chemistry of Dioxygen in FeCl2 Complexes with (2,3-Dimethoxyphenyl) α-Substituted Tripods in the tris(2-Pyridylmethyl)amine Series. Inorg Chem 2009; 48:4777-86. [DOI: 10.1021/ic802359z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Laila Benhamou
- Laboratoire de Chimie Biomimétique des Métaux de Transition, Institut de Chimie, UMR CNRS no. 7177, Université Louis Pasteur, 4 rue Blaise Pascal, B.P. 1032, F-67070 Strasbourg cedex, France
- Laboratoire d’Ingénierie des Matériaux Organométalliques et Moléculaires, Université Sidi Mohamed Ben Abdellah, Faculté des Sciences, BP 1796 (Atlas), 30000 Fez, Morocco
| | - Ahmed Machkour
- Laboratoire de Chimie Biomimétique des Métaux de Transition, Institut de Chimie, UMR CNRS no. 7177, Université Louis Pasteur, 4 rue Blaise Pascal, B.P. 1032, F-67070 Strasbourg cedex, France
- Laboratoire d’Ingénierie des Matériaux Organométalliques et Moléculaires, Université Sidi Mohamed Ben Abdellah, Faculté des Sciences, BP 1796 (Atlas), 30000 Fez, Morocco
| | - Olaf Rotthaus
- Laboratoire de Chimie Biomimétique des Métaux de Transition, Institut de Chimie, UMR CNRS no. 7177, Université Louis Pasteur, 4 rue Blaise Pascal, B.P. 1032, F-67070 Strasbourg cedex, France
| | - Mohammed Lachkar
- Laboratoire d’Ingénierie des Matériaux Organométalliques et Moléculaires, Université Sidi Mohamed Ben Abdellah, Faculté des Sciences, BP 1796 (Atlas), 30000 Fez, Morocco
| | - Richard Welter
- Laboratoire DECOMET, Institut de Chimie, UMR CNRS no. 7177, Université Louis Pasteur, 4 rue Blaise Pascal, B.P. 1032, F-67070 Strasbourg cedex, France
| | - Dominique Mandon
- Laboratoire de Chimie Biomimétique des Métaux de Transition, Institut de Chimie, UMR CNRS no. 7177, Université Louis Pasteur, 4 rue Blaise Pascal, B.P. 1032, F-67070 Strasbourg cedex, France
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Pirngruber GD, Frunz L, Lüchinger M. The characterisation and catalytic properties of biomimetic metal–peptide complexes immobilised on mesoporous silica. Phys Chem Chem Phys 2009; 11:2928-38. [DOI: 10.1039/b819678h] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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28
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Visvaganesan K, Suresh E, Palaniandavar M. Highly selective hydroxylation of alkanes catalyzed by (μ-oxo)bis(μ-carboxylato)-bridged diiron(iii) complexes: involvement of mononuclear iron(iii) species in catalysis. Dalton Trans 2009:3814-23. [DOI: 10.1039/b901508f] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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29
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Aromatic hydroxylation by molecular oxygen performed by mononuclear benzoato iron(II) complexes and preparation of new iron(III) complex with two minus ligand. INORG CHEM COMMUN 2008. [DOI: 10.1016/j.inoche.2007.12.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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30
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Comba P, Knoppe S, Martin B, Rajaraman G, Rolli C, Shapiro B, Stork T. Copper(II)-Mediated Aromaticortho-Hydroxylation: A Hybrid DFT and Ab Initio Exploration. Chemistry 2007; 14:344-57. [PMID: 17907133 DOI: 10.1002/chem.200700865] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mechanistic pathways for the aromatic hydroxylation by [CuII(L1)(TMAO)(O)](-) (L1=hippuric acid, TMAO=trimethylamine N-oxide), derived from the O--N bond homolysis of its [CuII(L1)(TMAO)2] precursor, were explored by using hybrid density functional theory (B3LYP) and highly correlated ab initio methods (QCISD and CCSD). Published experimental studies suggest that the catalytic reaction is triggered by a terminal copper-oxo species, and a detailed study of electronic structures, bonding, and energetics of the corresponding electromers is presented. Two pathways, a stepwise and a concerted reaction, were considered for the hydroxylation process. The results reveal a clear preference for the concerted pathway, in which the terminal oxygen atom directly attacks the carbon atom of the benzene ring, leading to the ortho-selectively hydroxylated product. Solvent effects were probed by using the PCM and CPCM solvation models, and the PCM model was found to perform better in the present case. Excellent agreement between the experimental and computational results was found, in particular also for changes in reactivity with derivatives of L1.
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Affiliation(s)
- Peter Comba
- Universität Heidelberg, Anorganisch-Chemisches Institut, INF 270, 69120 Heidelberg, Germany.
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31
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Nielsen A, Larsen FB, Bond AD, McKenzie CJ. Regiospecific ligand oxygenation in iron complexes of a carboxylate-containing ligand mediated by a proposed Fe(v)-oxo species. Angew Chem Int Ed Engl 2007; 45:1602-6. [PMID: 16470759 DOI: 10.1002/anie.200502656] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Anne Nielsen
- University of Southern Denmark, Department of Chemistry, Campusvej 55, 5230 Odense M, Denmark
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32
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de Visser SP, Oh K, Han AR, Nam W. Combined experimental and theoretical study on aromatic hydroxylation by mononuclear nonheme iron(IV)-oxo complexes. Inorg Chem 2007; 46:4632-41. [PMID: 17444641 DOI: 10.1021/ic700462h] [Citation(s) in RCA: 155] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The hydroxylation of aromatic compounds by mononuclear nonheme iron(IV)-oxo complexes, [FeIV(Bn-tpen)(O)]2+ (Bn-tpen=N-benzyl-N,N',N'-tris(2-pyridylmethyl)ethane-1,2-diamine) and [FeIV(N4Py)(O)]2+ (N4Py=N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine), has been investigated by a combined experimental and theoretical approach. In the experimental work, we have performed kinetic studies of the oxidation of anthracene with nonheme iron(IV)-oxo complexes generated in situ, thereby determining kinetic and thermodynamic parameters, a Hammett rho value, and a kinetic isotope effect (KIE) value. A large negative Hammett rho value of -3.9 and an inverse KIE value of 0.9 indicate that the iron-oxo group attacks the aromatic ring via an electrophilic pathway. By carrying out isotope labeling experiments, the oxygen in oxygenated products was found to derive from the nonheme iron(IV)-oxo species. In the theoretical work, we have conducted density functional theory (DFT) calculations on the hydroxylation of benzene by [FeIV(N4Py)(O)]2+. The calculations show that the reaction proceeds via two-state reactivity patterns on competing triplet and quintet spin states via an initial rate determining electrophilic substitution step. In analogy to heme iron(IV)-oxo catalysts, the ligand is noninnocent and actively participates in the reaction mechanism by reshuttling a proton from the ipso position to the oxo group. Calculated kinetic isotope effects of C6H6 versus C6D6 confirm an inverse isotope effect for the electrophilic substitution pathway. Based on the experimental and theoretical results, we have concluded that the aromatic ring oxidation by mononuclear nonheme iron(IV)-oxo complexes does not occur via a hydrogen atom abstraction mechanism but involves an initial electrophilic attack on the pi-system of the aromatic ring to produce a tetrahedral radical or cationic sigma-complex.
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Affiliation(s)
- Sam P de Visser
- Department of Chemistry, Division of Nano Sciences, and Center for Biomimetic Systems, Ewha Womans University, Seoul 120-750, Korea.
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33
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Romakh VB, Therrien B, Süss-Fink G, Shul'pin GB. Synthesis, Molecular Structure, and Catalytic Potential of the Tetrairon Complex [Fe4(N3O2-L)4(μ-O)2]4+ (L = 1-Carboxymethyl-4,7-dimethyl-1,4,7-triazacyclononane). Inorg Chem 2007; 46:3166-75. [PMID: 17373788 DOI: 10.1021/ic062207k] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction of iron sulfate with 1-carboxymethyl-4,7-dimethyl-1,4,7-triazacyclononane (L) and hydrogen peroxide in aqueous ethanol gives a brown dinuclear complex considered to be [Fe2(N3O-L)2(mu-O)(mu-OOCCH3)] + (1), which converts upon standing in acetonitrile solution into the green tetranuclear complex [Fe4(N3O2-L)4(mu-O)2]4+ (2). A single-crystal X-ray structure analysis of [2][PF6]4.5MeCN reveals 2 to contain four iron(III) centers, each of which is coordinated to three nitrogen atoms of a triazacyclononane ligand and is bridged by one oxo and two carboxylato bridges, a structural feature known from the active center of methane monooxygenase. Accordingly, complex 2 was found to catalyze the oxidative functionalization of methane with hydrogen peroxide in aqueous solution to give methanol, methyl hydroperoxide, and formic acid; the total turnover numbers attain 24 catalytic cycles within 4 h. To gain more insight into the catalytic process, the catalytic potential of 2 was also studied for the oxidation of higher alkanes, cycloalkanes, and isopropanol in acetonitrile, as well as in aqueous solution. The bond selectivities of the oxidation of linear and branched alkanes suggest a ferroxy radical pathway.
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Affiliation(s)
- Vladimir B Romakh
- Institut de Chimie, Université de Neuchâtel, CH-2009 Neuchâtel, Switzerland, and Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow 119991, Russia
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34
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Diiron(II) complexes showing a reversible oxygenation induced by a proton transfer mediated with a water molecule. Biological implication of a water molecule in hemerythrin function. J Organomet Chem 2007. [DOI: 10.1016/j.jorganchem.2006.04.052] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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35
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Komatsu H, Ochiai B, Hino T, Endo T. Model reaction for thermally latent curing through addition of hemiacetal ester and epoxide by schiff-base–zinc halide complexes. ACTA ACUST UNITED AC 2007. [DOI: 10.1002/pola.22087] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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36
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Yamashita M, Furutachi H, Tosha T, Fujinami S, Saito W, Maeda Y, Takahashi K, Tanaka K, Kitagawa T, Suzuki M. Regioselective Arene Hydroxylation Mediated by a (μ-Peroxo)diiron(III) Complex: A Functional Model for Toluene Monooxygenase. J Am Chem Soc 2006; 129:2-3. [PMID: 17199259 DOI: 10.1021/ja063987z] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mai Yamashita
- Division of Material Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
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37
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Nielsen A, Larsen FB, Bond AD, McKenzie CJ. Regiospecific Ligand Oxygenation in Iron Complexes of a Carboxylate-Containing Ligand Mediated by a Proposed FeV–Oxo Species. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.200502656] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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38
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Selective Conversion of Hydrocarbons with H2O2 Using Biomimetic Non-heme Iron and Manganese Oxidation Catalysts. ADVANCES IN INORGANIC CHEMISTRY 2006. [DOI: 10.1016/s0898-8838(05)58002-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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39
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Oh NY, Seo MS, Lim MH, Consugar MB, Park MJ, Rohde JU, Han J, Kim KM, Kim J, Que L, Nam W. Self-hydroxylation of perbenzoic acids at a nonheme iron(II) center. Chem Commun (Camb) 2005:5644-6. [PMID: 16292376 DOI: 10.1039/b511302d] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Treatment of mononuclear nonheme iron(II) complexes bearing two cis-labile sites with perbenzoic acids results in the self-hydroxylation of the aromatic ring to form the corresponding iron(III)-salicylate complexes through an intramolecular oxo-transfer process.
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Affiliation(s)
- Na Young Oh
- Department of Chemistry, Division of Nano Sciences and Center for Biomimetic Systems, Ewha Womans University, Seoul, 120-750, Korea
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40
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Taktak S, Flook M, Foxman BM, Que L, Rybak-Akimova EV. ortho-Hydroxylation of benzoic acids with hydrogen peroxide at a non-heme iron center. Chem Commun (Camb) 2005:5301-3. [PMID: 16244735 DOI: 10.1039/b508004e] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The iron-assisted hydroxylation of benzoic acid to salicylic acid by 1/H2O2 has been achieved in good yield under mild conditions (where is [Fe(II)(BPMEN)(CH3CN)2](ClO4)2 and BPMEN =N,N'-dimethyl-N,N'-bis(2-pyridylmethyl)ethane-1,2-diamine); the product of this reaction is a novel mononuclear iron(III) complex with a chelating salicylate.
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Affiliation(s)
- Sonia Taktak
- Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, MA 02155, USA
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41
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Oxidation of alkanes with m-chloroperbenzoic acid catalyzed by iron(III) chloride and a polydentate amine. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.molcata.2004.05.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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42
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Mekmouche Y, Ménage S, Pécaut J, Lebrun C, Reilly L, Schuenemann V, Trautwein A, Fontecave M. Mechanistic Tuning of Hydrocarbon Oxidations with H2O2, Catalyzed by Hexacoordinate Ferrous Complexes. Eur J Inorg Chem 2004. [DOI: 10.1002/ejic.200300926] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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43
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Mathieu D, Bartoli JF, Battioni P, Mansuy D. Monooxygenation of aromatic compounds by dioxygen with bioinspired systems using non-heme iron catalysts and tetrahydropterins: comparison with other reducing agents and interesting regioselectivity favouring meta-hydroxylation. Tetrahedron 2004. [DOI: 10.1016/j.tet.2004.03.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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44
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Chatterjee D, Mitra A, Shepherd RE. Oxo-transfer catalysis from t-BuOOH with C–H bond insertion using tridentate Schiff-base-chelate complexes of ruthenium(III). Inorganica Chim Acta 2004. [DOI: 10.1016/j.ica.2003.07.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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45
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Costas M, Mehn MP, Jensen MP, Que L. Dioxygen Activation at Mononuclear Nonheme Iron Active Sites: Enzymes, Models, and Intermediates. Chem Rev 2004; 104:939-86. [PMID: 14871146 DOI: 10.1021/cr020628n] [Citation(s) in RCA: 2014] [Impact Index Per Article: 100.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Miquel Costas
- Departament de Quimica, Universitat de Girona, 17071, Girona, Spain
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46
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Tshuva EY, Lippard SJ. Synthetic Models for Non-Heme Carboxylate-Bridged Diiron Metalloproteins: Strategies and Tactics. Chem Rev 2004; 104:987-1012. [PMID: 14871147 DOI: 10.1021/cr020622y] [Citation(s) in RCA: 536] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Edit Y Tshuva
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Furutachi H, Murayama M, Shiohara A, Yamazaki S, Fujinami S, Uehara A, Suzuki M, Ogo S, Watanabe Y, Maeda Y. Regioselective hydroxylation of the xylyl linker in a diiron(III) complex having a carboxylate-rich ligand with H2O2. Chem Commun (Camb) 2003:1900-1. [PMID: 12932023 DOI: 10.1039/b304171a] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Reaction of a diiron(III) complex having a xylta4- ligand (N,N,N',N'-m-xylylenediamine tetraacetate) with H2O2 resulted in regioselective hydroxylation of the m-xylyl linker. The reaction mimics the self-hydroxylation of a phenylalanine side chain found for ribonucleotide reductase (R2-W48F/D84E).
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Affiliation(s)
- Hideki Furutachi
- Department of Chemistry, Faculty of Science, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
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Mehn MP, Fujisawa K, Hegg EL, Que L. Oxygen activation by nonheme iron(II) complexes: alpha-keto carboxylate versus carboxylate. J Am Chem Soc 2003; 125:7828-42. [PMID: 12823001 DOI: 10.1021/ja028867f] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Mononuclear iron(II) alpha-keto carboxylate and carboxylate compounds of the sterically hindered tridentate face-capping ligand Tp(Ph2) (Tp(Ph2) = hydrotris(3,5-diphenylpyrazol-1-yl)borate) were prepared as models for the active sites of nonheme iron oxygenases. The structures of an aliphatic alpha-keto carboxylate complex, [Fe(II)(Tp(Ph2))(O(2)CC(O)CH(3))], and the carboxylate complexes [Fe(II)(Tp(Ph2))(OBz)] and [Fe(II)(Tp(Ph2))(OAc)(3,5-Ph(2)pzH)] were determined by single-crystal X-ray diffraction, all of which have five-coordinate iron centers. Both the alpha-keto carboxylate and the carboxylate compounds react with dioxygen resulting in the hydroxylation of a single ortho phenyl position of the Tp(Ph2) ligand. The oxygenation products were characterized spectroscopically, and the structure of the octahedral iron(III) phenolate product [Fe(III)(Tp(Ph2))(OAc)(3,5-Ph(2)pzH)] was established by X-ray diffraction. The reaction of the alpha-keto carboxylate model compounds with oxygen to produce the phenolate product occurs with concomitant oxidative decarboxylation of the alpha-keto acid. Isotope labeling studies show that (18)O(2) ends up in the Tp(Ph2) phenolate oxygen and the carboxylate derived from the alpha-keto acid. The isotope incorporation mirrors the dioxygenase nature of the enzymatic systems. Parallel studies on the carboxylate complexes demonstrate that the oxygen in the hydroxylated ligand is also derived from molecular oxygen. The oxygenation of the benzoylformate complex is demonstrated to be first order in metal complex and dioxygen, with activation parameters DeltaH++ = 25 +/- 2 kJ mol(-1) and DeltaS++ = -179 +/- 6 J mol(-1) K(-1). The rate of appearance of the iron(III) phenolate product is sensitive to the nature of the substituent on the benzoylformate ligand, exhibiting a Hammett rho value of +1.3 indicative of a nucleophilic mechanism. The proposed reaction mechanism involves dioxygen binding to produce an iron(III) superoxide species, nucleophilic attack of the superoxide at the alpha-keto functionality, and oxidative decarboxylation of the adduct to afford the oxidizing species that attacks the Tp(Ph2) phenyl ring. Interestingly, the alpha-keto carboxylate complexes react 2 orders of magnitude faster than the carboxylate complexes, thus emphasizing the key role that the alpha-keto functionality plays in oxygen activation by alpha-keto acid-dependent iron enzymes.
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Affiliation(s)
- Mark P Mehn
- Department of Chemistry and Center for Metals in Biocatalysis, 207 Pleasant Street Southeast, University of Minnesota, Minneapolis, MN 55455, USA
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Balogh-Hergovich É, Speier G, Réglier M, Giorgi M, Kuzmann E, Vértes A. Synthesis, Structure, and Catalytic Activity of New μ-Oxo-Bridged Diiron(III) Complexes. Eur J Inorg Chem 2003. [DOI: 10.1002/ejic.200200575] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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de Souza VR, Nunes GS, Rocha RC, Toma HE. Spectroscopy, electrochemistry and catalytic properties of rutheniumII complexes containing the tetradentate Schiff base ligand N,N′-bis(7-methyl-2-pyridylmethylene)-1,3-diiminopropane. Inorganica Chim Acta 2003. [DOI: 10.1016/s0020-1693(02)01480-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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