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Bohn A, Sénéchal‐David K, Rebilly J, Herrero C, Leibl W, Anxolabéhère‐Mallart E, Banse F. Heterolytic O-O Bond Cleavage Upon Single Electron Transfer to a Nonheme Fe(III)-OOH Complex. Chemistry 2022; 28:e202201600. [PMID: 35735122 PMCID: PMC9804275 DOI: 10.1002/chem.202201600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Indexed: 01/05/2023]
Abstract
The one-electron reduction of the nonheme iron(III)-hydroperoxo complex, [FeIII (OOH)(L5 2 )]2+ (L5 2 =N-methyl-N,N',N'-tris(2-pyridylmethyl)ethane-1,2-diamine), carried out at -70 °C results in the release of dioxygen and in the formation of [FeII (OH)(L5 2 )]+ following a bimolecular process. This reaction can be performed either with cobaltocene as chemical reductant, or electrochemically. These experimental observations are consistent with the disproportionation of the hydroperoxo group in the putative FeII (OOH) intermediate generated upon reduction of the FeIII (OOH) starting complex. One plausible mechanistic scenario is that this disproportionation reaction follows an O-O heterolytic cleavage pathway via a FeIV -oxo species.
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Affiliation(s)
- Antoine Bohn
- Institut de Chimie Moléculaire et des Matériaux d'OrsayUniversité Paris-SaclayCNRS91405OrsayFrance
| | - Katell Sénéchal‐David
- Institut de Chimie Moléculaire et des Matériaux d'OrsayUniversité Paris-SaclayCNRS91405OrsayFrance
| | - Jean‐Noël Rebilly
- Institut de Chimie Moléculaire et des Matériaux d'OrsayUniversité Paris-SaclayCNRS91405OrsayFrance
| | - Christian Herrero
- Institut de Chimie Moléculaire et des Matériaux d'OrsayUniversité Paris-SaclayCNRS91405OrsayFrance
| | - Winfried Leibl
- Institute for Integrative Biology of the Cell (I2BC)Université Paris-Saclay, CEACNRS91198Gif-sur-YvetteFrance
| | | | - Frédéric Banse
- Institut de Chimie Moléculaire et des Matériaux d'OrsayUniversité Paris-SaclayCNRS91405OrsayFrance
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2
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Robinson AL, Rebilly J, Guillot R, Herrero C, Maisonneuve H, Banse F. A Tale of Two Complexes: Electro‐Assisted Oxidation of Thioanisole by an “O
2
Activator/Oxidizing Species” Tandem System of Non‐Heme Iron Complexes. Chemistry 2022; 28:e202200217. [DOI: 10.1002/chem.202200217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Amanda Lyn Robinson
- Institut de Chimie Moléculaire et des Matériaux d'Orsay Université Paris-Saclay CNRS 91405 Orsay cedex France
| | - Jean‐Noël Rebilly
- Institut de Chimie Moléculaire et des Matériaux d'Orsay Université Paris-Saclay CNRS 91405 Orsay cedex France
| | - Régis Guillot
- Institut de Chimie Moléculaire et des Matériaux d'Orsay Université Paris-Saclay CNRS 91405 Orsay cedex France
| | - Christian Herrero
- Institut de Chimie Moléculaire et des Matériaux d'Orsay Université Paris-Saclay CNRS 91405 Orsay cedex France
| | - Hélène Maisonneuve
- Institut de Chimie Moléculaire et des Matériaux d'Orsay Université Paris-Saclay CNRS 91405 Orsay cedex France
| | - Frédéric Banse
- Institut de Chimie Moléculaire et des Matériaux d'Orsay Université Paris-Saclay CNRS 91405 Orsay cedex France
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3
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Zhiltsova EP, Ibatullina MR, Lukashenko SS, Valeeva FG, Pashirova TN, Kutyreva MP, Zakharova LY. Complexes of 1-hexadecyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide with transition metal nitrates. Micelle-forming, solubilizing, and adsorption properties. Colloid J 2017. [DOI: 10.1134/s1061933x17050179] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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4
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Buron C, Groni S, Ségaud N, Mazerat S, Dragoe D, Fave C, Sénéchal-David K, Schöllhorn B, Banse F. Self-assembled monolayer formation of a (N 5)Fe(ii) complex on gold electrodes: electrochemical properties and coordination chemistry on a surface. Dalton Trans 2016; 45:19053-19061. [PMID: 27858029 DOI: 10.1039/c6dt03870k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A coordinatively unsaturated FeII complex bearing a pentadentate ligand (N,N',N'-tris(2-pyridyl-methyl)-1,2-diaminoethane) functionalized with a cyclic disulfide group has been prepared in order to graft reactive metal entities as self-assembled monolayers (SAMs) on gold electrodes. Prior to grafting, exogenous ligand exchange has been investigated by cyclic voltammetry (CV) in solution, showing that the nature of the first coordination sphere (N5)FeII-X (X = Cl-, OTf-, MeCN, acetone) can be tuned, thanks to the control of the chemical conditions. The FeII complex has been immobilized on gold electrodes by spontaneous (passive) adsorption as well as by an electro-assisted method. The resulting SAMs were characterised by XPS and AFM analyses. CV experiments implementing these SAMs as working electrodes showed that the first coordination sphere of the grafted FeII complex can be controlled by adjusting the chemical conditions, similarly to the studies in a homogeneous solution. Finally, the supported FeII complex proved to be reactive with superoxide generated at the electrode surface by reduction of dissolved dioxygen. Under the employed conditions, leaking of the metal complex was not observed.
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Affiliation(s)
- Charlotte Buron
- Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris Sud, Université Paris Saclay, CNRS, 91405, Orsay Cedex, France.
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5
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Affiliation(s)
- Gayatri Panchbhai
- Molecular Biomimetics; Department of Chemistry - Ångström Laboratory; Uppsala University; P. O. Box 523 75120 Uppsala Sweden
| | - Wangkheimayum Marjit Singh
- Molecular Biomimetics; Department of Chemistry - Ångström Laboratory; Uppsala University; P. O. Box 523 75120 Uppsala Sweden
| | - Biswanath Das
- Molecular Biomimetics; Department of Chemistry - Ångström Laboratory; Uppsala University; P. O. Box 523 75120 Uppsala Sweden
| | - Reuben T. Jane
- Molecular Biomimetics; Department of Chemistry - Ångström Laboratory; Uppsala University; P. O. Box 523 75120 Uppsala Sweden
| | - Anders Thapper
- Molecular Biomimetics; Department of Chemistry - Ångström Laboratory; Uppsala University; P. O. Box 523 75120 Uppsala Sweden
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Rondot L, Girgenti E, Oddon F, Marchi-Delapierre C, Jorge-Robin A, Ménage S. Catalysis without a headache: Modification of ibuprofen for the design of artificial metalloenzyme for sulfide oxidation. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.molcata.2016.02.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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7
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Roux Y, Ghattas W, Avenier F, Guillot R, Simaan AJ, Mahy JP. Synthesis and characterization of [Fe(BPMEN)ACC]SbF6: a structural and functional mimic of ACC-oxidase. Dalton Trans 2015; 44:5966-8. [DOI: 10.1039/c5dt00347d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Miming plants: an original synthesis led to the preparation of the first model of the active site of the ethylene-forming enzyme ACC-oxidase. The prepared complex is a structural and a functional model as it reacts with hydrogen peroxide to produce the phytohormone ethylene.
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Affiliation(s)
- Y. Roux
- Institut de Chimie Moléculaire et des Matériaux d'Orsay
- Université Paris Sud
- Orsay 91405 CEDEX
- France
| | - W. Ghattas
- Institut de Chimie Moléculaire et des Matériaux d'Orsay
- Université Paris Sud
- Orsay 91405 CEDEX
- France
| | - F. Avenier
- Institut de Chimie Moléculaire et des Matériaux d'Orsay
- Université Paris Sud
- Orsay 91405 CEDEX
- France
| | - R. Guillot
- Institut de Chimie Moléculaire et des Matériaux d'Orsay
- Université Paris Sud
- Orsay 91405 CEDEX
- France
| | - A. J. Simaan
- Aix Marseille Université
- Centrale Marseille
- 13397, Marseille
- France
| | - J.-P. Mahy
- Institut de Chimie Moléculaire et des Matériaux d'Orsay
- Université Paris Sud
- Orsay 91405 CEDEX
- France
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Ségaud N, Rebilly JN, Sénéchal-David K, Guillot R, Billon L, Baltaze JP, Farjon J, Reinaud O, Banse F. Iron Coordination Chemistry with New Ligands Containing Triazole and Pyridine Moieties. Comparison of the Coordination Ability of the N-Donors. Inorg Chem 2013; 52:691-700. [DOI: 10.1021/ic301834x] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Nathalie Ségaud
- Institut de
Chimie Moléculaire et des Matériaux d’Orsay, Université Paris Sud, F-91405 Orsay, France
| | - Jean-Noël Rebilly
- Laboratoire de Chimie et de
Biochimie Pharmacologiques et Toxicologiques, Université Paris Descartes, CNRS UMR 8601, F-75270 Paris Cedex
06, France
| | - Katell Sénéchal-David
- Institut de
Chimie Moléculaire et des Matériaux d’Orsay, Université Paris Sud, F-91405 Orsay, France
| | - Régis Guillot
- Institut de
Chimie Moléculaire et des Matériaux d’Orsay, Université Paris Sud, F-91405 Orsay, France
| | - Laurianne Billon
- Institut de
Chimie Moléculaire et des Matériaux d’Orsay, Université Paris Sud, F-91405 Orsay, France
| | - Jean-Pierre Baltaze
- Institut de
Chimie Moléculaire et des Matériaux d’Orsay, Université Paris Sud, F-91405 Orsay, France
| | - Jonathan Farjon
- Institut de
Chimie Moléculaire et des Matériaux d’Orsay, Université Paris Sud, F-91405 Orsay, France
| | - Olivia Reinaud
- Laboratoire de Chimie et de
Biochimie Pharmacologiques et Toxicologiques, Université Paris Descartes, CNRS UMR 8601, F-75270 Paris Cedex
06, France
| | - Frédéric Banse
- Institut de
Chimie Moléculaire et des Matériaux d’Orsay, Université Paris Sud, F-91405 Orsay, France
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Ye W, Ho DM, Friedle S, Palluccio TD, Rybak-Akimova EV. Role of Fe(IV)-oxo intermediates in stoichiometric and catalytic oxidations mediated by iron pyridine-azamacrocycles. Inorg Chem 2012; 51:5006-21. [PMID: 22534174 DOI: 10.1021/ic202435r] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An iron(II) complex with a pyridine-containing 14-membered macrocyclic (PyMAC) ligand L1 (L1 = 2,7,12-trimethyl-3,7,11,17-tetra-azabicyclo[11.3.1]heptadeca-1(17),13,15-triene), 1, was prepared and characterized. Complex 1 contains low-spin iron(II) in a pseudo-octahedral geometry as determined by X-ray crystallography. Magnetic susceptibility measurements (298 K, Evans method) and Mössbauer spectroscopy (90 K, δ = 0.50(2) mm/s, ΔE(Q) = 0.78(2) mm/s) confirmed that the low-spin configuration of Fe(II) is retained in liquid and frozen acetonitrile solutions. Cyclic voltammetry revealed a reversible one-electron oxidation/reduction of the iron center in 1, with E(1/2)(Fe(III)/Fe(II)) = 0.49 V vs Fc(+)/Fc, a value very similar to the half-wave potentials of related macrocyclic complexes. Complex 1 catalyzed the epoxidation of cyclooctene and other olefins with H(2)O(2). Low-temperature stopped-flow kinetic studies demonstrated the formation of an iron(IV)-oxo intermediate in the reaction of 1 with H(2)O(2) and concomitant partial ligand oxidation. A soluble iodine(V) oxidant, isopropyl 2-iodoxybenzoate, was found to be an excellent oxygen atom donor for generating Fe(IV)-oxo intermediates for additional spectroscopic (UV-vis in CH(3)CN: λ(max) = 705 nm, ε ≈ 240 M(-1) cm(-1); Mössbauer: δ = 0.03(2) mm/s, ΔE(Q) = 2.00(2) mm/s) and kinetic studies. The electrophilic character of the (L1)Fe(IV)═O intermediate was established in rapid (k(2) = 26.5 M(-1) s(-1) for oxidation of PPh(3) at 0 °C), associative (ΔH(‡) = 53 kJ/mol, ΔS(‡) = -25 J/K mol) oxidation of substituted triarylphosphines (electron-donating substituents increased the reaction rate, with a negative value of Hammet's parameter ρ = -1.05). Similar double-mixing kinetic experiments demonstrated somewhat slower (k(2) = 0.17 M(-1) s(-1) at 0 °C), clean, second-order oxidation of cyclooctene into epoxide with preformed (L1)Fe(IV)═O that could be generated from (L1)Fe(II) and H(2)O(2) or isopropyl 2-iodoxybenzoate. Independently determined rates of ferryl(IV) formation and its subsequent reaction with cyclooctene confirmed that the Fe(IV)-oxo species, (L1)Fe(IV)═O, is a kinetically competent intermediate for cyclooctene epoxidation with H(2)O(2) at room temperature. Partial ligand oxidation of (L1)Fe(IV)═O occurs over time in oxidative media, reducing the oxidizing ability of the ferryl species; the macrocyclic nature of the ligand is retained, resulting in ferryl(IV) complexes with Schiff base PyMACs. NH-groups of the PyMAC ligand assist the oxygen atom transfer from ferryl(IV) intermediates to olefin substrates.
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Affiliation(s)
- Wanhua Ye
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
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Smith SJ, Peralta RA, Jovito R, Horn A, Bortoluzzi AJ, Noble CJ, Hanson GR, Stranger R, Jayaratne V, Cavigliasso G, Gahan LR, Schenk G, Nascimento OR, Cavalett A, Bortolotto T, Razzera G, Terenzi H, Neves A, Riley MJ. Spectroscopic and Catalytic Characterization of a Functional FeIIIFeII Biomimetic for the Active Site of Uteroferrin and Protein Cleavage. Inorg Chem 2012; 51:2065-78. [DOI: 10.1021/ic201711p] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
| | | | | | | | | | | | | | - Robert Stranger
- Research School of Chemistry, Australian National University, Canberra 0200, Australia
| | - Vidura Jayaratne
- Research School of Chemistry, Australian National University, Canberra 0200, Australia
| | - Germán Cavigliasso
- Research School of Chemistry, Australian National University, Canberra 0200, Australia
| | | | - Gerhard Schenk
- Department of Chemistry, National University of Ireland—Maynooth, Maynooth County, Kildare, Ireland
| | - Otaciro R. Nascimento
- Instituto de Física, Universidade de São Paulo, 13560-970 São
Carlos, São Paulo, Brazil
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11
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Shin JW, Rowthu SR, Hyun MY, Song YJ, Kim C, Kim BG, Min KS. Monomeric, trimeric, and tetrameric transition metal complexes (Mn, Fe, Co) containing N,N-bis(2-pyridylmethyl)-2-aminoethanol/-ate: preparation, crystal structure, molecular magnetism and oxidation catalysis. Dalton Trans 2011; 40:5762-73. [PMID: 21523305 DOI: 10.1039/c1dt10028a] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Jong Won Shin
- Department of Chemistry Graduate School, Kyungpook National University, Daegu, 702-701, Republic of Korea
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Dengler JE, Lehenmeier MW, Klaus S, Anderson CE, Herdtweck E, Rieger B. A One-Component Iron Catalyst for Cyclic Propylene Carbonate Synthesis. Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.201000861] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Groni S, Hureau C, Guillot R, Blondin G, Blain G, Anxolabéhère-Mallart E. Characterizations of chloro and aqua Mn(II) mononuclear complexes with amino-pyridine ligands. Comparison of their electrochemical properties with those of Fe(II) counterparts. Inorg Chem 2009; 47:11783-97. [PMID: 19007154 DOI: 10.1021/ic8015172] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The solution behavior of mononuclear Mn(II) complexes, namely, [(L(5)(2))MnCl](+) (1), [(L(5)(3))MnCl](+) (2), [(L(5)(2))Mn(OH(2))](2+) (3), [(L(5)(3))Mn(OH(2))](2+) (4), and [(L(6)(2))Mn(OH(2))](2+) (6), with L(5)(2/3) and L(6)(2) being penta- and hexadentate amino-pyridine ligands, is investigated in MeCN using EPR, UV-vis spectroscopies, and electrochemistry. The addition of one chloride ion onto species 6 leads to the formation of the complex [(L(6)(2))MnCl](+) (5) that is X-ray characterized. EPR and UV-vis spectra indicate that structure and redox states of complexes 1-6 are maintained in MeCN solution. Chloro complexes 1, 2, and 5 show reversible Mn(II)/Mn(III) process at 0.95, 1.02, and 1.05 V vs SCE, respectively, whereas solvated complexes 3, 4, and 6 show an irreversible anodic peak around 1.5 V vs SCE. Electrochemical oxidations of 1 and 5 leading to the Mn(III) complexes [(L(5)(2))MnCl](2+) (7) and [(L(6)(2))MnCl](2+) (8) are successful. The UV-vis signatures of 7 and 8 show features associated with chloro to Mn(III) LMCT and d-d transitions. The X-ray characterization of the heptacoordinated Mn(III) species 8 is also reported. The analogous electrochemical generation of the corresponding Mn(III) complex was not possible when starting from 2. The new mixed-valence di-mu-oxo [(L(5)(2))Mn(muO)(2)Mn(L(5)(2))](3+) species (9) can be obtained from 3, whereas the sister [(L(5)(3))Mn(muO)(2)Mn(L(5)(3))](3+) species can not be generated from 4. Such different responses upon oxidations are commented on with the help of comparison with related Mn/Fe complexes and are discussed in relation with the size of the metallacycle formed between the diamino bridge and the metal center (5- vs 6-membered). Lastly, a comparison between redox potentials of the studied Mn(II) complexes with those of Fe(II) analogues is drawn and completed with previously reported data on Mn/Fe isostructural systems. This gives us the opportunity to get some indirect insights into the metal specificity encountered in enzymes among which superoxide dismutase is the archetypal model.
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Affiliation(s)
- Sihem Groni
- Equipe de Chimie Inorganique, Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris-Sud 11, UMR 8182 CNRS, Orsay F-91405, France
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Patra A, Sarkar S, Drew MG, Zangrando E, Chattopadhyay P. Synthesis and crystal structure characterization of iron(II), cobalt(II) and nickel(II) complexes with 1,3-bis(2-pyridylmethylthio)propane. Polyhedron 2009. [DOI: 10.1016/j.poly.2009.02.039] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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England J, Gondhia R, Bigorra-Lopez L, Petersen AR, White AJP, Britovsek GJP. Towards robust alkane oxidation catalysts: electronic variations in non-heme iron(ii) complexes and their effect in catalytic alkane oxidation. Dalton Trans 2009:5319-34. [DOI: 10.1039/b901390c] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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England J, Davies C, Banaru M, White AJ, Britovsek GJ. Catalyst Stability Determines the Catalytic Activity of Non-Heme Iron Catalysts in the Oxidation of Alkanes. Adv Synth Catal 2008. [DOI: 10.1002/adsc.200700462] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Abstract
A synthetic route to tetradentate chiral N(4) ligands has been developed with the aim to study the potential of corresponding iron and manganese complexes as catalysts for enantioselective epoxidation. These ligands, which contain two oxazoline rings and two trialkylamino groups as coordinating units, are readily prepared in enantiomerically pure form by the reaction of chiral 2-chloromethyloxazolines with achiral N,N'-dimethylethane-1,2-diamine or chiral (R,R)-N,N'-dimethylcyclohexane-1,2-diamine. The ligands derived from N,N'-dimethylethane-1,2-diamine reacted with anhydrous metal halides MnCl(2) and FeCl(2) in a stereoselective manner to give octahedral mononuclear complexes that have the general formula Delta-[(L)MCl(2)]. In contrast, the ligands derived from N,N'-dimethylcyclohexane-1,2-diamine formed complexes with different coordination modes depending on the diastereomer employed: in one case the metal ion was found to be pentacoordinate, in the other case a hexacoordinated complex was observed. The structure of a series of Fe and Mn complexes was determined by X-ray analysis. The coordination chemistry of these ligands was further studied by X-ray and NMR analyses of the diamagnetic isostructural complexes [(L)ZnCl(2)]. Analogous ionic complexes, which were prepared by removing chloride with silver trifluoromethanesulfonate or hexafluoroantimonate, were tested as catalysts for the epoxidation of olefins.
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Affiliation(s)
- Geoffroy Guillemot
- Department of Chemistry, University of Basel, St. Johanns-Ring 19, 4056 Basel, Switzerland
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Taktak S, Ye W, Herrera AM, Rybak-Akimova EV. Synthesis and Catalytic Properties in Olefin Epoxidation of Novel Iron(II) Complexes with Pyridine-Containing Macrocycles Bearing an Aminopropyl Pendant Arm. Inorg Chem 2007; 46:2929-42. [PMID: 17335276 DOI: 10.1021/ic070094e] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Three novel iron(II) complexes with pyridine-containing macrocycles bearing an aminopropyl pendant arm were synthesized and characterized. Crystal structures of two of the complexes revealed high-spin iron(II) centers coordinated to the five ligand nitrogen atoms with no coordination of either the solvent molecules or anions, resulting in an unusual square-pyramidal geometry. Related tetradentate ligand CRH formed a low-spin iron(II) complex (meso form was structurally characterized) with a planar arrangement of the four nitrogen atoms from the macrocycle and two axial acetonitrile molecules. Similarly to the corresponding nickel and copper complexes of the pentadentate ligands, the protonation of the amino group on the ligand arm in iron(II) complexes was found to be reversible. Spectral changes and magnetic susceptibility measurements indicated that a change in the geometry and spin state of the metal center is associated with this acid-base process. In the presence of noncoordinating acids (e.g., triflic acid), these complexes, as well as their nonmethylated analogue, can efficiently catalyze the epoxidation of cyclooctene and 1-decene under mild conditions, using hydrogen peroxide as the oxidant. However, in the deprotonated form or in the presence of coordinating acids like HCl, no epoxidation occurs.
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Affiliation(s)
- Sonia Taktak
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, USA
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Leovac VM, Novaković SB, Bogdanović GA, Joksović MD. Synthesis and reaction of Schiff base 4-(pyridin-3-ylmethylimino)-pent-2-en-2-ol with FeCl3. Struct Chem 2007. [DOI: 10.1007/s11224-007-9148-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Britovsek GJP, England J, White AJP. Iron(ii), manganese(ii) and cobalt(ii) complexes containing tetradentate biphenyl-bridged ligands and their application in alkane oxidation catalysis. Dalton Trans 2006:1399-408. [PMID: 16518509 DOI: 10.1039/b513886h] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of manganese(II), iron(II) and cobalt(II) bis(triflate) complexes containing linear tetradentate bis(imine) and bis(amine) ligands with a biphenyl bridge have been synthesized. The twist in the ligand backbone due to the biphenyl unit leads in the case of the bis(imine) ligands (1 and 2) containing sp2 hybridised N donors, to a distorted cis-alpha coordination geometry, whereas in the case of the biphenyl- and biphenylether-bridged bis(amine) ligands (7 - 9 and 12), a trans coordination geometry is observed. The catalytic properties of the complexes for the oxidation of cyclohexane, using H2O2 as the oxidant, have been evaluated. Only the iron complexes show any catalytic activity under the conditions used, but the low conversions and selectivies observed indicate that these catalysts lead predominantly to free radical auto-oxidation.
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Britovsek GJP, England J, White AJP. Non-heme Iron(II) Complexes Containing Tripodal Tetradentate Nitrogen Ligands and Their Application in Alkane Oxidation Catalysis. Inorg Chem 2005; 44:8125-34. [PMID: 16241163 DOI: 10.1021/ic0509229] [Citation(s) in RCA: 266] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of iron(II) bis(triflate) complexes containing tripodal tetradentate nitrogen ligands with pyridine and dimethylamine donors of the type [N(CH(2)Pyr)(3-n)()(CH(2)CH(2)NMe(2))(n)] [n = 0 (tpa, 1), n = 1 (iso-bpmen, 3), n = 2 (Me(4)-benpa, 4), n = 3 (Me(6)-tren, 5)] and the linear tetradentate ligand [(CH(2)Pyr)MeN(CH(2)CH(2))NMe(CH(2)Pyr), (bpmen, 2)] has been prepared. The preferred coordination geometry of these complexes in the solid state and in CH(2)Cl(2) solution changes from six- to five-coordinate in the order from 1 to 5. In acetonitrile, the triflate ligands of all complexes are readily displaced by acetonitrile ligands. The complex [Fe(1)(CH(3)CN)(2)](2+) is essentially low spin at room temperature, whereas ligands with fewer pyridine donors increase the preference for high-spin Fe(II). Both the number of pyridine donors and the spin state of the metal center strongly affect the intensity of a characteristic MLCT band around 400 nm. The catalytic properties of the complexes for the oxidation of alkanes have been evaluated, using cyclohexane as the substrate. Complexes containing ligands 1-3 are more active and selective catalysts, possibly operating via a metal-based oxidation mechanism, whereas complexes containing ligands 4 and 5 give rise to Fenton-type chemistry.
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Albela B, Carina R, Policar C, Poussereau S, Cano J, Guilhem J, Tchertanov L, Blondin G, Delroisse M, Girerd JJ. Synthesis and X-ray Structure of the MnIICl2 and MnIIIF2 Complexes of N,N‘-Dimethyl-2,11-diaza[3,3](2,6)pyridinophane. High-Field Electron Paramagnetic Resonance and Density Funtional Theory Studies of the Mn(III) Complex. Evidence for a Low-Lying Spin Triplet State. Inorg Chem 2005; 44:6959-66. [PMID: 16180857 DOI: 10.1021/ic048302f] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Two manganese complexes, (py2(NMe)2)MnIICl2 (1) and [(py2(NMe)2)MnIIIF2]+ (2), are here described with the macrocyclic ligand py2(NMe)2 (py2(NMe)2 = N,N'-dimethyl-2,11-diaza[3,3](2,6)pyridinophane). For both, the crystal structure is reported. The UV-visible spectrum of 2 exhibits a very broad near-infrared (NIR) band corresponding to the transition between the two e(g)-type orbitals split by the Jahn-Teller effect. A negative D value of ca. -4 cm(-1) was estimated by high-field and high-frequency electron paramagnetic resonance (HF-EPR) spectroscopy, which was consistent with symmetry considerations. Density functional theory (DFT) calculations on 2 support the 5B1 electronic ground state predicted from the X-ray structure. Moreover, to explain the large value of the D parameter, a spin triplet first excited spin state was postulated to occur at low energy. This was confirmed by the DFT calculations.
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Affiliation(s)
- Belén Albela
- Laboratoire de Chimie Inorganique, UMR 8613, UMR 8124, Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris-Sud, France
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Chikate RC, Padhye SB. Transition metal quinone–thiosemicarbazone complexes 2: Magnetism, ESR and redox behavior of iron (II), iron (III), cobalt (II) and copper (II) complexes of 2-thiosemicarbazido-1,4-naphthoquinone. Polyhedron 2005. [DOI: 10.1016/j.poly.2005.04.037] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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25
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Tanase S, Bouwman E, Long GJ, Shahin AM, Gelder RD, Mills AM, Spek AL, Reedijk J. Bis(μ-alkoxo)-bridged dinuclear iron(III) complexes of pyrazole-based ligands as models for iron-oxo proteins. Polyhedron 2005; 24:41-8. [DOI: 10.1016/j.poly.2004.07.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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26
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Eduard, Duban A, Konstantin, Bryliakov P, Evgenii, Talsi P. Characterization of low-spin ferric hydroperoxo complexes with N,N’-dimethyl-N,N’-bis(2-pyridylmethyl)-1,2-diaminoethane. Mendeleev Communications 2005. [DOI: 10.1070/mc2005v015n01abeh001981] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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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] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Balland V, Anxolabéhère-Mallart E, Banse F, Rivière E, Bourcier S, Nierlich M, Girerd JJ. Synthesis, Structure and Characterizations in Solid State and Solution of Dinuclear Pentacoordinated FeII and MnII Complexes and of a Linear Tetranuclear FeIII Complex Obtained with the LigandN,N,N′,N′-Tetrakis[(6-methyl-2-pyridyl)methyl]propane-1,3-diamine. Eur J Inorg Chem 2004. [DOI: 10.1002/ejic.200300374] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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29
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Darkhovskii MB, Pletnev IV, Tchougréeff AL. Low- and high-spin iron (II) complexes studied by effective crystal field method combined with molecular mechanics. J Comput Chem 2003; 24:1703-19. [PMID: 12964189 DOI: 10.1002/jcc.10300] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A computational method targeted to Werner-type complexes is developed on the basis of quantum mechanical effective Hamiltonian crystal field (EHCF) methodology (previously proposed for describing electronic structure of transition metal complexes) combined with the Gillespie-Kepert version of molecular mechanics (MM). It is a special version of the hybrid quantum/MM approach. The MM part is responsible for representing the whole molecule, including ligand atoms and metal ion coordination sphere, but leaving out the effects of the d-shell. The quantum mechanical EHCF part is limited to the metal ion d-shell. The method reproduces with reasonable accuracy geometry and spin states of the Fe(II) complexes with monodentate and polydentate aromatic ligands with nitrogen donor atoms. In this setting a single set of MM parameters set is shown to be sufficient for handling all spin states of the complexes under consideration.
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Affiliation(s)
- M B Darkhovskii
- L. Y. Karpov Institute of Physical Chemistry, Vorontsovo pole 10, Moscow 105064, Russia
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Banse F, Balland V, Philouze C, Rivière E, Tchertanova L, Girerd J. Mono- and dinuclear FeIII complexes with the tridentate N-ethyl-N-(2-aminoethyl)salicylaldiminato ligand. X-ray structures, magnetic and spectroscopic properties. Inorganica Chim Acta 2003; 353:223-30. [DOI: 10.1016/s0020-1693(03)00292-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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31
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Balland V, Banse F, Anxolabéhère-Mallart E, Nierlich M, Girerd JJ. Iron Complexes Containing the Ligand N,N-Bis(6-methyl-2-pyridylmethyl)-N,N-bis(2-pyridylmethyl)ethane-1,2-diamine: Structural, Spectroscopic, and Electrochemical Studies, Reactivity with Hydrogen Peroxide and the Formation of a Low-Spin Fe−OOH Complex. Eur J Inorg Chem 2003. [DOI: 10.1002/ejic.200200694] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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32
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Balland V, Banse F, Anxolabéhère-Mallart E, Ghiladi M, Mattioli TA, Philouze C, Blondin G, Girerd JJ. Fe(II) and Fe(III) mononuclear complexes with a pentadentate ligand built on the 1,3-diaminopropane unit. Structures and spectroscopic and electrochemical properties. Reaction with H2O2. Inorg Chem 2003; 42:2470-7. [PMID: 12665386 DOI: 10.1021/ic025905n] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two new iron complexes, [L(5)(3)Fe(II)Cl]PF(6) (1.PF(6)) and [(L(5)(3)H(+))Fe(III)Cl(3)]PF(6) (2.PF(6)), were synthesized (L(5)(3) = N-methyl-N,N',N'-tris(2-pyridylmethyl)propane-1,3-diamine), and their molecular structures were determined by X-ray crystallography. Their behavior in solution was studied by UV-vis spectroscopy and electrochemistry. Upon addition of a base to an acetonitrile solution of 2, the new unsymmetrical dinuclear complex [L(5)(3)Fe(III)OFe(III)Cl(3)](+) was detected. Treating 1 with hydrogen peroxide has allowed us to detect the low spin [L(5)(3)Fe(III)OOH](2+). Its spectroscopic properties (UV-vis, EPR and resonance Raman) are similar to those reported for related FeOOH complexes obtained with amine/pyridine ligands. Using stopped-flow absorption spectroscopy, the formation and degradation of [L(5)(3)Fe(III)OOH](2+) has been monitored, and a mechanism is proposed to reproduce the kinetic data.
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Affiliation(s)
- Véronique Balland
- Laboratoire de Chimie Inorganique, UMR CNRS 8613, Université Paris-Sud, 91405 Orsay, France
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Smithson RJ, Kilner CA, Brough AR, Halcrow MA. Iron(II) complexes of (pyrazol-3-yl)pyrazine. Anion-dependent formation of a hydrogen-bonded, chiral nanoporous lattice. Polyhedron 2003. [DOI: 10.1016/s0277-5387(02)01403-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Kooistra T, Hekking K, Knijnenburg Q, de Bruin B, Budzelaar P, de Gelder R, Smits J, Gal A. Cobalt Chloride Complexes of N3 and N4 Donor Ligands. Eur J Inorg Chem 2003. [DOI: 10.1002/ejic.200390090] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Sokolov M, Umakoshi K, Sasaki Y. N,N,N ',N '-Tetrakis(2-pyridylmethyl)ethylenediamine and its analogues as hypodentate ligands. Synthesis and characterization of the rhodium(III), ruthenium(II), and palladium(II) complexes. Inorg Chem 2002; 41:6237-43. [PMID: 12444765 DOI: 10.1021/ic0203264] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
New complexes of Rh(III), Ru(II), and Pd(II) with N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (tpen) and its analogues have been prepared. The reaction of RhCl(3).nH(2)O with tpen is slow and allows one to isolate the products of three consecutive substitution steps: Rh(2)Cl(6)(tpen) (1), cis-[RhCl(2)(eta(4)-tpen)](+) (2), and [RhCl(eta(5)-tpen)](2+) (3). In acetonitrile the reaction stops at the step of the formation of cis-[RhCl(2)(eta(4)-tpen)](+), whereas [RhCl(eta(5)-tpen)](2+) is the final product of the further reaction in ethanol. Fully chelated [Rh(tpen)](3+) could not be obtained. Bis(acetylacetonato)palladium(II), Pd(acac)(2), reacts with tpen and its analogues, N,N,N',N'-tetrakis(2-pyridylmethyl)-1,3-propanediamine (tptn) and N,N,N',N'-tetrakis(2-pyridylmethyl)-(R)-1,2-propylenediamine (R-tppn), to give [Pd(eta(4)-tpen)](2+) (4), [Pd(eta(4)-tppn)](2+) (5), and [Pd(eta(4)-tptn)](2+) (6), respectively. Two pyridyl arms remain uncoordinated in these cases. The formation of unstable Pd(III) complexes from these Pd(II) complexes in solution was suggested on the basis of electrochemical measurements. Ruthenium(III) trichloride, RuCl(3).nH(2)O, is reduced to give a Ru(II) complex with fully coordinated tpen, [Ru(tpen)](2+) (7). The same product was obtained in a more straightforward reaction of Ru(II)Cl(2)(dimethyl sulfoxide)(4) with tpen. Electrochemical studies showed a quasi-reversible [Ru(tpen)](2+/3+) couple for [7](ClO(4))(2) (E(1/2) = 1.05 V vs Ag/AgCl). Crystal structures of [2](PF(6)).2CH(3)CN, [3](PF(6))(2).CH(3)CN, [6](ClO(4))(2), and [7](ClO(4))(2).0.5H(2)O were determined. Crystal data: [2](PF(6)).2CH(3)CN, monoclinic, C2, a = 16.974(4) A, b = 8.064(3) A, c = 13.247(3) A, beta = 106.37(2) degrees, V = 1739.9(8) A(3), Z = 2; [3](PF(6))(2).CH(3)CN, triclinic, P1, a = 11.430(1) A, b = 19.234(3) A, c = 8.101(1) A, alpha = 99.43(1) degrees, beta = 93.89(1) degrees, gamma = 80.10(1) degrees, V = 1729.3(4) A(3), Z = 2; [6](ClO(4))(2), orthorhombic, Pnna, a = 8.147(1) A, b = 25.57(1) A, c = 14.770(4) A, V = 3076(3) A(3), Z = 4; [7](ClO(4))(2).0.5H(2)O, monoclinic, P2(1)/c, a = 10.046(7) A, b = 19.049(2) A, c = 15.696(3) A, beta = 101.46(3) degrees, V = 2943(2) A(3), Z = 4.
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Affiliation(s)
- Maxim Sokolov
- Institute of Inorganic Chemistry, Novosibirsk, Russia
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Graziani O, Toupet L, Hamon JR, Tilset M. An unexpected deboronation of [tBuB(3-tBuC3H2N2)3]− in a reaction with iron(II) chloride, and the X-ray crystal structure of trans-FeCl2(tBuC3H3N2)4. Inorganica Chim Acta 2002. [DOI: 10.1016/s0020-1693(02)01178-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Raffard N, Balland V, Simaan J, Létard S, Nierlich M, Miki K, Banse F, Anxolabéhère-Mallart E, Girerd JJ. Bio-inspired iron catalysts for degradation of aromatic pollutants and alkane hydroxylation. CR CHIM 2002. [DOI: 10.1016/s1631-0748(02)01359-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Hazell A, McKenzie CJ, Nielsen LP, Schindler S, Weitzer M. Mononuclear non-heme iron(iii) peroxide complexes: syntheses, characterisation, mass spectrometric and kinetic studies. ACTA ACUST UNITED AC 2002. [DOI: 10.1039/b103844n] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Jo DH, Chiou YM, Que L. Models for extradiol cleaving catechol dioxygenases: syntheses, structures, and reactivities of iron(II)-monoanionic catecholate complexes. Inorg Chem 2001; 40:3181-90. [PMID: 11399191 DOI: 10.1021/ic001185d] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Crystallographic and spectroscopic studies of extradiol cleaving catechol dioxygenases indicate that the enzyme-substrate complexes have both an iron(II) center and a monoanionic catecholate. Herein we report a series of iron(II)-monoanionic catecholate complexes, [(L)Fe(II)(catH)](X) (1a, L = 6-Me(3)-TPA (tris(6-methyl-2-pyridylmethyl)amine), catH = CatH (1,2-catecholate monoanion); 1b, L = 6-Me(3)-TPA, catH = DBCH (3,5-di-tert-butyl-1,2-catecholate monoanion); 1c, L = 6-Me(2)-bpmcn (N,N'-dimethyl-N,N'-bis(6-methyl-2-pyridylmethyl)-trans-1,2-diaminocyclohexane), catH = CatH; 1d, L = 6-Me(2)-bpmcn, catH = DBCH), that model such enzyme complexes. The crystal structure of [(6-Me(2)-bpmcn)Fe(II)(DBCH)](+) (1d) shows that the DBCH ligand binds to the iron asymmetrically as previously reported for 1b, with two distinct Fe-O bonds of 1.943(1) and 2.344(1) A. Complexes 1 react with O(2) or NO to afford blue-purple iron(III)-catecholate dianion complexes, [(L)Fe(III)(cat)](+) (2). Interestingly, crystallographically characterized 2d, isolated from either reaction, has the N-methyl groups in a syn configuration, in contrast to the anti configuration of the precursor complex, so epimerization of the bound ligand must occur in the course of isolating 2d. This notion is supported by the fact that the UV-vis and EPR properties of in situ generated 2d(anti) differ from those of isolated 2d(syn). While the conversion of 1 to 2 in the presence of O(2) occurs without an obvious intermediate, that in the presence of NO proceeds via a metastable S = (3)/(2) [(L)Fe(catH)(NO)](+) adduct 3, which can only be observed spectroscopically but not isolated. Intermediates 3a and 3b subsequently disproportionate to afford two distinct complexes, [(6-Me(3)-TPA)Fe(III)(cat)](+) (2a and 2b) and [(6-Me(3)-TPA)Fe(NO)(2)](+) (4) in comparable yield, while 3d converts to 2d in 90% yield. Complexes 2b and anti-2d react further with O(2) over a 24 h period and afford a high yield of cleavage products. Product analysis shows that the products mainly derive from intradiol cleavage but with a small extent of extradiol cleavage (89:3% for 2b and 78:12% for anti-2d). The small amounts of the extradiol cleavage products observed may be due to the dissociation of an alpha-methyl substituted pyridyl arm, generating a complex with a tridentate ligand. Surprisingly, syn-2d does not react with O(2) over the course of 4 days. These results suggest that there are a number of factors that influence the mode and rate of cleavage of catechols coordinated to iron centers.
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Affiliation(s)
- D H Jo
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, MN 55455, USA
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Poussereau S, Blondin G, Chottard G, Guilhem J, Tchertanov L, Rivière E, Girerd JJ. Synthesis, Structure and Characterization of the New Complex [L1(H2O)Fe(μ-O)Fe(OH2)L1]4+ [L1 =N,N′-Bis(1-methylimidazolyl-2-methyl)-N,N′-Bismethyl-1,2-ethanediamine] − Formation of the (μ-O)(μ-H3O2) Complex upon Deprotonation. Eur J Inorg Chem 2001. [DOI: 10.1002/1099-0682(200104)2001:4<1057::aid-ejic1057>3.0.co;2-a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Grapperhaus CA, Mienert B, Bill E, Weyhermüller T, Wieghardt K. 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. Inorg Chem 2000; 39:5306-17. [PMID: 11187471 DOI: 10.1021/ic0005238] [Citation(s) in RCA: 271] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Reaction of the monoanionic, pentacoordinate ligand lithium 1,4,8,11-tetraazacyclotetradecane-1-acetate, Li(cyclam-acetate), with FeCl3 yields, upon addition of KPF6, [(cyclam-acetato)FeCl]PF6 (1) as a red microcrystalline solid. Addition of excess NaN3 prior to addition of KPF6 yields the azide derivative [(cyclam-acetato)FeN3]PF6 (2a) as orange microcrystals. The X-ray crystal structure of the azide derivative has been determined as the tetraphenylborate salt (2b). Reaction of 1 with silver triflate yields [(cyclam-acetato)Fe(O3SCF3)]PF6 (3), which partially dissociates triflate in nondried solvents to yield a mixture of triflate and aqua bound species. Each of the iron(III) derivatives is low-spin (d5, S = 1/2) as determined by variable-temperature magnetic susceptibility measurements, Mössbauer and EPR spectroscopy. The low-spin iron(II) (d6, S = 0) complexes 1red and 2ared have been prepared by electrochemical and chemical methods and have been characterized by Mössbauer spectroscopy. Photolysis of 2a at 419 nm in frozen acetonitrile yields a nearly colorless species in approximately 80% conversion with an isomer shift delta = -0.04 mm/s and a quadrupole splitting delta EQ = -1.67 mm/s. A spin-Hamiltonian analysis of the magnetic Mössbauer spectra is consistent with an FeV ion (d3, S = 3/2). The proposed [(cyclam-acetato)FeV=N]+ results from the photooxidation of 2a via heterolytic N-N cleavage of coordinated azide. Photolysis of 2a in acetonitrile solution at -35 degrees C (300 nm) or 20 degrees C (Hg immersion lamp) results primarily in photoreduction via homolytic Fe-Nazide cleavage yielding FeII (d,6 S = 0) with an isomer shift delta = 0.56 mm/s and quadrupole splitting delta EQ = 0.54 mm/s. A minor product containing high-valent iron is suggested by Mössbauer spectroscopy and is proposed to originate from [((cyclam-acetato)Fe)2(mu-N)]2+ with a mixed-valent (FeIV(mu-N)FeIII))4+S = 1/2 core. Exposure of 3 to a stream of oxygen/ozone at low temperatures (-80 degrees C) in acetone/water results in a single oxidized product with an isomer shift delta = 0.01 mm/s and quadrupole splitting delta EQ = 1.37 mm/s. A spin-Hamiltonian analysis of the magnetic Mössbauer yields parameters similar to those of compound II of horseradish peroxidase which are consistent with an FeIV=O monomeric complex (S = 1).
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Affiliation(s)
- C A Grapperhaus
- Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
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