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Meng F, Sun L, Liu Y, Li X, Tan H, Yuan C, Li X. Theoretical investigation of the reaction mechanism of THP oxidative rearrangement catalysed by BBOX. Phys Chem Chem Phys 2024. [PMID: 39015023 DOI: 10.1039/d4cp01661k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2024]
Abstract
γ-Butyrobetaine hydroxylase (BBOX) is a non-heme FeII/2OG dependent enzyme that is able to perform two different kinds of catalytic reactions on 3-(2,2,2-trimethylhydrazinium) propionate (THP) to produce distinct catalytic products. Although the structure of BBOX complexed with THP has been resolved, the details of its catalytic mechanism are still elusive. In this study, by employing molecular dynamics (MD) simulations and density functional theory (DFT) calculations, the mechanism of the THP oxidative rearrangement reactions catalysed by BBOX was investigated. Our calculations revealed how the enzyme undergoes a conformational conversion to initiate the catalytic reactions. In the first catalytic step, BBOX performs hydrogen abstraction from the substrate THP as a common non-heme iron enzyme. Due to the structure of the substrate stabilizing the radical species and polarizing the adjacent N-N bond, in the next step, THP takes the pathway for N-N bond homolysis but not regular hydroxyl rebounding. The cleaved ammonium radical could either react with the hydroxyl group on the iron centre of the enzyme or recombine with the other cleaved fragment of the substrate to generate the rearranged product. This study revealed the catalytic mechanism of BBOX, detailing how the enzyme and the substrate regulated the hydroxyl rebound process to generate various products.
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Affiliation(s)
- Fanqi Meng
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Lu Sun
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Yueying Liu
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Xiang Li
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Hongwei Tan
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Chang Yuan
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
| | - Xichen Li
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
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2
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Pagès-Vilà N, Gamba I, Clémancey M, Latour JM, Company A, Costas M. Proton-triggered chemoselective halogenation of aliphatic C-H bonds with nonheme Fe IV-oxo complexes. J Inorg Biochem 2024; 259:112643. [PMID: 38924872 DOI: 10.1016/j.jinorgbio.2024.112643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 05/30/2024] [Accepted: 06/14/2024] [Indexed: 06/28/2024]
Abstract
Halogenation of aliphatic C-H bonds is a chemical transformation performed in nature by mononuclear nonheme iron dependent halogenases. The mechanism involves the formation of an iron(IV)-oxo-chloride species that abstracts the hydrogen atom from the reactive C-H bond to form a carbon-centered radical that selectively reacts with the bound chloride ligand, a process commonly referred to as halide rebound. The factors that determine the halide rebound, as opposed to the reaction with the incipient hydroxide ligand, are not clearly understood and examples of well-defined iron(IV)-oxo-halide compounds competent in C-H halogenation are scarce. In this work we have studied the reactivity of three well-defined iron(IV)-oxo complexes containing variants of the tetradentate 1-(2-pyridylmethyl)-1,4,7-triazacyclononane ligand (Pytacn). Interestingly, these compounds exhibit a change in their chemoselectivity towards the functionalization of C-H bonds under certain conditions: their reaction towards C-H bonds in the presence of a halide anionleads to exclusive oxygenation, while the addition of a superacid results in halogenation. Almost quantitative halogenation of ethylbenzene is observed when using the two systems with more sterically congested ligands and even the chlorination of strong C-H bonds such as those of cyclohexane is performed when a methyl group is present in the sixth position of the pyridine ring of the ligand. Mechanistic studies suggest that both reactions, oxygenation and halogenation, proceed through a common rate determining hydrogen atom transfer step and the presence of the acid dictates the fate of the resulting alkyl radical towards preferential halogenation over oxygenation.
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Affiliation(s)
- Neus Pagès-Vilà
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/ Maria Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain
| | - Ilaria Gamba
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/ Maria Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain; Departamento de Química, Facultad de Ciencias, Universidad de La Laguna, Av. Astrofísico Sánchez s/n, 38200 La Laguna, Spain.
| | - Martin Clémancey
- Univ. Grenoble Alpes, CNRS, CEA, IRIG, Laboratoire de Chimie et Biologie des Métaux, F-38000 Grenoble, France
| | - Jean-Marc Latour
- Univ. Grenoble Alpes, CNRS, CEA, IRIG, Laboratoire de Chimie et Biologie des Métaux, F-38000 Grenoble, France
| | - Anna Company
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/ Maria Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain.
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/ Maria Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain.
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3
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Kumar R, Ansari A, Comba P, Rajaraman G. Rebound or Cage Escape? The Role of the Rebound Barrier for the Reactivity of Non-Heme High-Valent Fe IV =O Species. Chemistry 2024; 30:e202303300. [PMID: 37929771 DOI: 10.1002/chem.202303300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 11/03/2023] [Accepted: 11/06/2023] [Indexed: 11/07/2023]
Abstract
Owing to their high reactivity and selectivity, variations in the spin ground state and a range of possible pathways, high-valent FeIV =O species are popular models with potential bioinspired applications. An interesting example of a structure-reactivity pattern is the detailed study with five nonheme amine-pyridine pentadentate ligand FeIV =O species, including N4py: [(L1 )FeIV =O]2+ (1), bntpen: [(L2 )FeIV =O]2+ (2), py2 tacn: [(L3 )FeIV =O]2+ (3), and two isomeric bispidine derivatives: [(L4 )FeIV =O]2+ (4) and [(L5 )FeIV =O]2+ (5). In this set, the order of increasing reactivity in the hydroxylation of cyclohexane differs from that with cyclohexadiene as substrate. A comprehensive DFT, ab initio CASSCF/NEVPT2 and DLPNO-CCSD(T) study is presented to untangle the observed patterns. These are well reproduced when both activation barriers for the C-H abstraction and the OH rebound are taken into account. An MO, NBO and deformation energy analysis reveals the importance of π(pyr) → π*xz (FeIII -OH) electron donation for weakening the FeIII -OH bond and thus reducing the rebound barrier. This requires that pyridine rings are oriented perpendicularly to the FeIII -OH bond and this is a subtle but crucial point in ligand design for non-heme iron alkane hydroxylation.
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Affiliation(s)
- Ravi Kumar
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, Powai, 400076, India
| | - Azaj Ansari
- Department of Chemistry, Central University of Haryana, Haryana, 123031, India
| | - Peter Comba
- Institute of Inorganic Chemistry &, Interdisciplinary Center for Scientific Computing, Heidelberg University, 69120, Heidelberg, Germany
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai, Powai, 400076, India
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4
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Dantignana V, Pérez-Segura MC, Besalú-Sala P, Delgado-Pinar E, Martínez-Camarena Á, Serrano-Plana J, Álvarez-Núñez A, Castillo CE, García-España E, Luis JM, Basallote MG, Costas M, Company A. Characterization of a Ferryl Flip in Electronically Tuned Nonheme Complexes. Consequences in Hydrogen Atom Transfer Reactivity. Angew Chem Int Ed Engl 2023; 62:e202211361. [PMID: 36305539 PMCID: PMC10107328 DOI: 10.1002/anie.202211361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Indexed: 12/04/2022]
Abstract
Two oxoiron(IV) isomers (R 2a and R 2b) of general formula [FeIV (O)(R PyNMe3 )(CH3 CN)]2+ are obtained by reaction of their iron(II) precursor with NBu4 IO4 . The two isomers differ in the position of the oxo ligand, cis and trans to the pyridine donor. The mechanism of isomerization between R 2a and R 2b has been determined by kinetic and computational analyses uncovering an unprecedented path for interconversion of geometrical oxoiron(IV) isomers. The activity of the two oxoiron(IV) isomers in hydrogen atom transfer (HAT) reactions shows that R 2a reacts one order of magnitude faster than R 2b, which is explained by a repulsive noncovalent interaction between the ligand and the substrate in R 2b. Interestingly, the electronic properties of the R substituent in the ligand pyridine ring do not have a significant effect on reaction rates. Overall, the intrinsic structural aspects of each isomer define their relative HAT reactivity, overcoming changes in electronic properties of the ligand.
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Affiliation(s)
- Valeria Dantignana
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - M Carmen Pérez-Segura
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Instituto de Biomoléculas (INBIO), Universidad de Cádiz, Puerto Real, 11510, Cádiz, Spain
| | - Pau Besalú-Sala
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Estefanía Delgado-Pinar
- Departamento de Química Inorgánica, Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, C/Catedrático José Beltrán, Paterna, 46980, Valencia 2, Spain
| | - Álvaro Martínez-Camarena
- Departamento de Química Inorgánica, Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, C/Catedrático José Beltrán, Paterna, 46980, Valencia 2, Spain
| | - Joan Serrano-Plana
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Andrea Álvarez-Núñez
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Carmen E Castillo
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Instituto de Biomoléculas (INBIO), Universidad de Cádiz, Puerto Real, 11510, Cádiz, Spain
| | - Enrique García-España
- Departamento de Química Inorgánica, Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, C/Catedrático José Beltrán, Paterna, 46980, Valencia 2, Spain
| | - Josep M Luis
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Manuel G Basallote
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Instituto de Biomoléculas (INBIO), Universidad de Cádiz, Puerto Real, 11510, Cádiz, Spain
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Anna Company
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
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5
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Han J, Tan L, Wan Y, Li G, Anderson SN. C(sp 3)-H oxidation and chlorination catalysed by a bioinspired pincer iron(III) complex. Dalton Trans 2022; 51:11620-11624. [PMID: 35895115 DOI: 10.1039/d2dt02005j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A pincer iron(III) catalyst for the oxidation and chlorination of C(sp3)-H bonds was developed. Oxidation of a diagnostic substrate cis-decalin implies that a long-lived carbon-centred radical is involved. Mechanistic studies suggest that an Fe-oxo species could be responsible for the rate-determining C-H activation step. This report expands the scope of non-heme catalysts for C-H functionalisation.
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Affiliation(s)
- Jian Han
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah, 84322, USA.
| | - Liming Tan
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah, 84322, USA.
| | - Yanjun Wan
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah, 84322, USA.
| | - Gang Li
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah, 84322, USA.
| | - Stephen N Anderson
- Department of Chemistry and Biochemistry, Utah State University, Logan, Utah, 84322, USA.
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6
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Cheng J, Shiota Y, Yamasaki M, Izukawa K, Tachi Y, Yoshizawa K, Shimakoshi H. Mechanistic Study for the Reaction of B 12 Complexes with m-Chloroperbenzoic Acid in Catalytic Alkane Oxidations. Inorg Chem 2022; 61:9710-9724. [PMID: 35696150 DOI: 10.1021/acs.inorgchem.2c01174] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The oxidation of alkanes with m-chloroperbenzoic acid (mCPBA) catalyzed by the B12 derivative, heptamethyl cobyrinate, was investigated under several conditions. During the oxidation of cyclohexane, heptamethyl cobyrinate works as a catalyst to form cyclohexanol and cyclohexanone at a 0.67 alcohol to ketone ratio under aerobic conditions in 1 h. The reaction rate shows a first-order dependence on the [catalyst] and [mCPBA] while being independent of [cyclohexane]; Vobs = k2[catalyst][mCPBA]. The kinetic deuterium isotope effect was determined to be 1.86, suggesting that substrate hydrogen atom abstraction is not dominantly involved in the rate-determining step. By the reaction of mCPBA and heptamethyl cobyrinate at low temperature, the corresponding cobalt(III)acylperoxido complex was formed which was identified by UV-vis, IR, ESR, and ESI-MS studies. A theoretical study suggested the homolysis of the O-O bond in the acylperoxido complex to form Co(III)-oxyl (Co-O•) and the m-chlorobenzoyloxyl radical. Radical trapping experiments using N-tert-butyl-α-phenylnitrone and CCl3Br, product analysis of various alkane oxidations, and computer analysis of the free energy for radical abstraction from cyclohexane by Co(III)-oxyl suggested that both Co(III)-oxyl and the m-chlorobenzoyloxyl radical could act as hydrogen-atom transfer reactants for the cyclohexane oxidation.
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Affiliation(s)
- Jiamin Cheng
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, 744, Nishi-ku, Motooka, Fukuoka 819-0395, Japan
| | - Yoshihito Shiota
- Institute for Materials Chemistry and Engineering, Kyushu University, 744, Nishi-ku, Motooka, Fukuoka 819-0395, Japan
| | - Mikako Yamasaki
- Graduate School of Science, Osaka City University, Osaka 558-8585, Japan
| | - Kureha Izukawa
- Graduate School of Science, Osaka City University, Osaka 558-8585, Japan
| | - Yoshimitsu Tachi
- Graduate School of Science, Osaka City University, Osaka 558-8585, Japan
| | - Kazunari Yoshizawa
- Institute for Materials Chemistry and Engineering, Kyushu University, 744, Nishi-ku, Motooka, Fukuoka 819-0395, Japan
| | - Hisashi Shimakoshi
- Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, 744, Nishi-ku, Motooka, Fukuoka 819-0395, Japan
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7
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Zelenka J, Pereverzev A, Jahn U, Roithová J. Sulfonyl Nitrene and Amidyl Radical: Structure and Reactivity. Chemistry 2022; 28:e202104493. [PMID: 35266598 PMCID: PMC9323475 DOI: 10.1002/chem.202104493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Indexed: 11/10/2022]
Abstract
Photocatalytic generation of nitrenes and radicals can be used to tune or even control their reactivity. Photocatalytic activation of sulfonyl azides leads to the elimination of N2 and the resulting reactive species initiate C−H activations and amide formation reactions. Here, we present reactive radicals that are generated from sulfonyl azides: sulfonyl nitrene radical anion, sulfonyl nitrene and sulfonyl amidyl radical, and test their gas phase reactivity in C−H activation reactions. The sulfonyl nitrene radical anion is the least reactive and its reactivity is governed by the proton coupled electron transfer mechanism. In contrast, sulfonyl nitrene and sulfonyl amidyl radicals react via hydrogen atom transfer pathways. These reactivities and detailed characterization of the radicals with vibrational spectroscopy and with DFT calculations provide information necessary for taking control over the reactivity of these intermediates.
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Affiliation(s)
- Jan Zelenka
- Department of Spectroscopy and Catalysis Institute for Molecules and Materials Radboud University Nijmegen, Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
| | - Aleksandr Pereverzev
- Department of Spectroscopy and Catalysis Institute for Molecules and Materials Radboud University Nijmegen, Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
| | - Ullrich Jahn
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences Flemingovo náměstí 2 16610 Prague 6 Czech Republic
| | - Jana Roithová
- Department of Spectroscopy and Catalysis Institute for Molecules and Materials Radboud University Nijmegen, Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
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8
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Rhoda HM, Heyer AJ, Snyder BER, Plessers D, Bols ML, Schoonheydt RA, Sels BF, Solomon EI. Second-Sphere Lattice Effects in Copper and Iron Zeolite Catalysis. Chem Rev 2022; 122:12207-12243. [PMID: 35077641 DOI: 10.1021/acs.chemrev.1c00915] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Transition-metal-exchanged zeolites perform remarkable chemical reactions from low-temperature methane to methanol oxidation to selective reduction of NOx pollutants. As with metalloenzymes, metallozeolites have impressive reactivities that are controlled in part by interactions outside the immediate coordination sphere. These second-sphere effects include activating a metal site through enforcing an "entatic" state, controlling binding and access to the metal site with pockets and channels, and directing radical rebound vs cage escape. This review explores these effects with emphasis placed on but not limited to the selective oxidation of methane to methanol with a focus on copper and iron active sites, although other transition-metal-ion zeolite reactions are also explored. While the actual active-site geometric and electronic structures are different in the copper and iron metallozeolites compared to the metalloenzymes, their second-sphere interactions with the lattice or the protein environments are found to have strong parallels that contribute to their high activity and selectivity.
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Affiliation(s)
- Hannah M Rhoda
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Alexander J Heyer
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Benjamin E R Snyder
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Dieter Plessers
- Department of Microbial and Molecular Systems, Center for Sustainable Catalysis and Engineering, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Max L Bols
- Department of Microbial and Molecular Systems, Center for Sustainable Catalysis and Engineering, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Robert A Schoonheydt
- Department of Microbial and Molecular Systems, Center for Sustainable Catalysis and Engineering, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Bert F Sels
- Department of Microbial and Molecular Systems, Center for Sustainable Catalysis and Engineering, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Edward I Solomon
- Department of Chemistry, Stanford University, Stanford, California 94305, United States.,Photon Science, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
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9
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Fujimoto T, Hirata Y, Sugimoto H, Miyanishi M, Shiota Y, Yoshizawa K, Itoh S. C(sp 3)-H bond activation by the carboxylate-adduct of osmium tetroxide (OsO 4). Dalton Trans 2021; 51:1123-1130. [PMID: 34951431 DOI: 10.1039/d1dt03819b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction of osmium tetroxide (OsO4) and carboxylate anions (acetate: X- = AcO- and benzoate: X- = BzO-) gave 1 : 1 adducts, [OsO4(X)]- (1X), the structures of which were determined by X-ray crystallographic analysis. In both cases, the carboxylate anion X coordinates to the osmium centre to generate a distorted trigonal bipyramidal osmium(VIII) complex. The carboxylate adducts show a negative shift of the redox potentials (E1/2) and a red shift of the νOsO stretches as compared to those of tetrahedral OsO4 itself. Despite the negative shift of E1/2, the reactivity of these adduct complexes 1X was enhanced compared to that of OsO4 in benzylic C(sp3)-H bond oxidation. The reaction obeyed the first-order kinetics on both 1X and the substrates, giving the second-order rate constant (k2), which exhibits a linear correlation with the C-H bond dissociation energy (BDEC-H) of the substrates (xanthene, 9,10-dihydroanthracene, fluorene and 1,2,3,4-tetrahydronaphthalene) and a kinetic deuterium isotope effect (KIE) of 9.7 (k2(xanthene-h2)/k2(xanthene-d2)). On the basis of these kinetic data together with the DFT calculation results, we propose a stepwise reaction mechanism involving rate-limiting benzylic hydrogen atom abstraction and subsequent rebound of the generated organic radical intermediate to a remaining oxido group on the osmium centre.
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Affiliation(s)
- Tomohiro Fujimoto
- Department of Molecular Chemistry, Division of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Yuka Hirata
- Department of Molecular Chemistry, Division of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Hideki Sugimoto
- Department of Molecular Chemistry, Division of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Mayuko Miyanishi
- Institute for Material Chemistry and Engineering and International Research Center for Molecular System, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
| | - Yoshihito Shiota
- Institute for Material Chemistry and Engineering and International Research Center for Molecular System, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
| | - Kazunari Yoshizawa
- Institute for Material Chemistry and Engineering and International Research Center for Molecular System, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
| | - Shinobu Itoh
- Department of Molecular Chemistry, Division of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
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10
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Kondo M, Tatewaki H, Masaoka S. Design of molecular water oxidation catalysts with earth-abundant metal ions. Chem Soc Rev 2021; 50:6790-6831. [PMID: 33977932 DOI: 10.1039/d0cs01442g] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The four-electron oxidation of water (2H2O → O2 + 4H+ + 4e-) is considered the main bottleneck in artificial photosynthesis. In nature, this reaction is catalysed by a Mn4CaO5 cluster embedded in the oxygen-evolving complex of photosystem II. Ruthenium-based complexes have been successful artificial molecular catalysts for mimicking this reaction. However, for practical and large-scale applications in the future, molecular catalysts that contain earth-abundant first-row transition metal ions are preferred owing to their high natural abundance, low risk of depletion, and low costs. In this review, the frontier of water oxidation reactions mediated by first-row transition metal complexes is described. Special attention is paid towards the design of molecular structures of the catalysts and their reaction mechanisms, and these factors are expected to serve as guiding principles for creating efficient and robust molecular catalysts for water oxidation using ubiquitous elements.
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Affiliation(s)
- Mio Kondo
- Division of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan. and Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI), Osaka University, Suita, Osaka 565-0871, Japan and JST, PRESTO, 4-1-8 Honcho, Kawaguchi, 332-0012, Japan
| | - Hayato Tatewaki
- Division of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Shigeyuki Masaoka
- Division of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan. and Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI), Osaka University, Suita, Osaka 565-0871, Japan
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11
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Morimoto Y, Hanada S, Kamada R, Fukatsu A, Sugimoto H, Itoh S. Hydroxylation of Unactivated C(sp 3)-H Bonds with m-Chloroperbenzoic Acid Catalyzed by an Iron(III) Complex Supported by a Trianionic Planar Tetradentate Ligand. Inorg Chem 2021; 60:7641-7649. [PMID: 33400861 DOI: 10.1021/acs.inorgchem.0c03469] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hydroxylation of cyclohexane with m-chloroperbenzoic acid was examined in the presence of an iron(III) complex supported by a trianionic planar tetradentate ligand. The present reaction system shows a high turnover number of 2750 with a high product selectivity of alcohol (93%). The turnover frequency was 0.51 s-1, and the second-order rate constant (k) for the C-H bond activation of cyclohexane was 1.08 M-1 s-1, which is one of the highest values among the iron complexes in the oxidation of cyclohexane so far reported. The present catalytic system can be adapted to the hydroxylation of substrates having only primary C-H bonds such as 2,2,3,3-tetramethylbutane as well as gaseous alkanes such as butane, propane, and ethane. The involvement of an iron(III) acyl peroxido complex as the reactive species was suggested by spectroscopic measurements of the reaction solution.
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Affiliation(s)
- Yuma Morimoto
- Department of Molecular Chemistry, Division of Applied Chemistry, Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan
| | - Shinichi Hanada
- Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan
| | - Ryusuke Kamada
- Department of Molecular Chemistry, Division of Applied Chemistry, Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan
| | - Arisa Fukatsu
- Department of Material and Life Science, Division of Advanced Science and Biotechnology, Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan
| | - Hideki Sugimoto
- Department of Molecular Chemistry, Division of Applied Chemistry, Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan
| | - Shinobu Itoh
- Department of Molecular Chemistry, Division of Applied Chemistry, Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan
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12
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Castillo CE, Gamba I, Vicens L, Clémancey M, Latour JM, Costas M, Basallote MG. Spin State Tunes Oxygen Atom Transfer towards Fe IV O Formation in Fe II Complexes. Chemistry 2021; 27:4946-4954. [PMID: 33350013 DOI: 10.1002/chem.202004921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Indexed: 11/08/2022]
Abstract
Oxoiron(IV) complexes bearing tetradentate ligands have been extensively studied as models for the active oxidants in non-heme iron-dependent enzymes. These species are commonly generated by oxidation of their ferrous precursors. The mechanisms of these reactions have seldom been investigated. In this work, the reaction kinetics of complexes [FeII (CH3 CN)2 L](SbF6 )2 ([1](SbF6 )2 and [2](SbF6 )2 ) and [FeII (CF3 SO3 )2 L] ([1](OTf)2 and [2](OTf)2 (1, L=Me,H Pytacn; 2, L=nP,H Pytacn; R,R' Pytacn=1-[(6-R'-2-pyridyl)methyl]-4,7- di-R-1,4,7-triazacyclononane) with Bu4 NIO4 to form the corresponding [FeIV (O)(CH3 CN)L]2+ (3, L=Me,H Pytacn; 4, L=nP,H Pytacn) species was studied in acetonitrile/acetone at low temperatures. The reactions occur in a single kinetic step with activation parameters independent of the nature of the anion and similar to those obtained for the substitution reaction with Cl- as entering ligand, which indicates that formation of [FeIV (O)(CH3 CN)L]2+ is kinetically controlled by substitution in the starting complex to form [FeII (IO4 )(CH3 CN)L]+ intermediates that are converted rapidly to oxo complexes 3 and 4. The kinetics of the reaction is strongly dependent on the spin state of the starting complex. A detailed analysis of the magnetic susceptibility and kinetic data for the triflate complexes reveals that the experimental values of the activation parameters for both complexes are the result of partial compensation of the contributions from the thermodynamic parameters for the spin-crossover equilibrium and the activation parameters for substitution. The observation of these opposite and compensating effects by modifying the steric hindrance at the ligand illustrates so far unconsidered factors governing the mechanism of oxygen atom transfer leading to high-valent iron oxo species.
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Affiliation(s)
- Carmen E Castillo
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica, y Química Inorgánica, Facultad de Ciencias, Instituto de Biomoléculas (INBIO), Universidad de Cádiz, Puerto Real, Cádiz, 11510, Spain
| | - Ilaria Gamba
- Grup de Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT), Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, Campus de Montilivi, Girona, 17071, Catalonia, Spain
| | - Laia Vicens
- Grup de Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT), Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, Campus de Montilivi, Girona, 17071, Catalonia, Spain
| | - Martin Clémancey
- CEA, CNRS, IRIG, DIESE, LCBM, Université Grenoble Alpes, pmb, 38000, Grenoble, France
| | - Jean-Marc Latour
- CEA, CNRS, IRIG, DIESE, LCBM, Université Grenoble Alpes, pmb, 38000, Grenoble, France
| | - Miquel Costas
- Grup de Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT), Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, Campus de Montilivi, Girona, 17071, Catalonia, Spain
| | - Manuel G Basallote
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica, y Química Inorgánica, Facultad de Ciencias, Instituto de Biomoléculas (INBIO), Universidad de Cádiz, Puerto Real, Cádiz, 11510, Spain
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13
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Schneider JE, Goetz MK, Anderson JS. Statistical analysis of C-H activation by oxo complexes supports diverse thermodynamic control over reactivity. Chem Sci 2021; 12:4173-4183. [PMID: 34163690 PMCID: PMC8179456 DOI: 10.1039/d0sc06058e] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/28/2021] [Indexed: 01/29/2023] Open
Abstract
Transition metal oxo species are key intermediates for the activation of strong C-H bonds. As such, there has been interest in understanding which structural or electronic parameters of metal oxo complexes determine their reactivity. Factors such as ground state thermodynamics, spin state, steric environment, oxygen radical character, and asynchronicity have all been cited as key contributors, yet there is no consensus on when each of these parameters is significant or the relative magnitude of their effects. Herein, we present a thorough statistical analysis of parameters that have been proposed to influence transition metal oxo mediated C-H activation. We used density functional theory (DFT) to compute parameters for transition metal oxo complexes and analyzed their ability to explain and predict an extensive data set of experimentally determined reaction barriers. We found that, in general, only thermodynamic parameters play a statistically significant role. Notably, however, there are independent and significant contributions from the oxidation potential and basicity of the oxo complexes which suggest a more complicated thermodynamic picture than what has been shown previously.
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Affiliation(s)
| | - McKenna K Goetz
- Department of Chemistry, University of Chicago Chicago IL 60637 USA
| | - John S Anderson
- Department of Chemistry, University of Chicago Chicago IL 60637 USA
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14
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Tavani F, Capocasa G, Martini A, Sessa F, Di Stefano S, Lanzalunga O, D'Angelo P. Activation of C-H bonds by a nonheme iron(IV)-oxo complex: mechanistic evidence through a coupled EDXAS/UV-Vis multivariate analysis. Phys Chem Chem Phys 2021; 23:1188-1196. [PMID: 33355324 DOI: 10.1039/d0cp04304d] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The understanding of reactive processes involving organic substrates is crucial to chemical knowledge and requires multidisciplinary efforts for its advancement. Herein, we apply a combined multivariate, statistical and theoretical analysis of coupled time-resolved X-ray absorption (XAS)/UV-Vis data to obtain detailed mechanistic information for on the C-H bond activation of 9,10-dihydroanthracene (DHA) and diphenylmethane (Ph2CH2) by the nonheme FeIV-oxo complex [N4Py·FeIV(O)]2+ (N4Py = N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine) in CH3CN at room temperature. Within this approach, we determine the number of key chemical species present in the reaction mixtures and derive spectral and concentration profiles for the reaction intermediates. From the quantitative analysis of the XAS spectra the transient intermediate species are structurally determined. As a result, it is suggested that, while DHA is oxidized by [N4Py·FeIV(O)]2+ with a hydrogen atom transfer-electron transfer (HAT-ET) mechanism, Ph2CH2 is oxidized by the nonheme iron-oxo complex through a HAT-radical dissociation pathway. In the latter process, we prove that the intermediate FeIII complex [N4Py·FeIII(OH)]2+ is not able to oxidize the diphenylmethyl radical and we provide its structural characterization in solution. The employed combined experimental and theoretical strategy is promising for the spectroscopic characterization of transient intermediates as well as for the mechanistic investigation of redox chemical transformations on the second to millisecond time scales.
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Affiliation(s)
- Francesco Tavani
- Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro 5, 00185 Roma, Italy.
| | - Giorgio Capocasa
- Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro 5, 00185 Roma, Italy.
| | - Andrea Martini
- Dipartimento di Chimica, Università degli Studi di Torino, Via P. Giuria 7, 10125 Torino, Italy and The Smart Materials Research Institute, Southern Federal University, 344090 Sladkova 178/24 Rostov-on-Don, Russia
| | - Francesco Sessa
- Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro 5, 00185 Roma, Italy.
| | - Stefano Di Stefano
- Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro 5, 00185 Roma, Italy.
| | - Osvaldo Lanzalunga
- Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro 5, 00185 Roma, Italy.
| | - Paola D'Angelo
- Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro 5, 00185 Roma, Italy.
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15
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Sánchez-Eguía BN, Serrano-Plana J, Company A, Costas M. Catalytic O 2 activation with synthetic models of α-ketoglutarate dependent oxygenases. Chem Commun (Camb) 2020; 56:14369-14372. [PMID: 33150337 DOI: 10.1039/d0cc05942k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An iron complex bearing the facially capping tridentate 1,4,7-triazacyclononane ligand mimics structural and functional features of alpha-ketoglutarate (α-KG) dependent enzymes, and engages in enzyme-like catalytic O2 activation coupled to α-ketoacid decarboxylation, oxygenating sulfides. This system constitutes a rare case of non-enzymatic catalytic O2 activation, cycling between FeII and FeIV(O).
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Affiliation(s)
- Brenda N Sánchez-Eguía
- Grup de Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT), Institut de Química Computacional i Catàlisi (IQCC), Universitat de Girona. Facultat de Ciències, Campus de Montilivi, 17003, Girona, Spain.
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16
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Park H, Lee D. Ligand Taxonomy for Bioinorganic Modeling of Dioxygen-Activating Non-Heme Iron Enzymes. Chemistry 2020; 26:5916-5926. [PMID: 31909506 DOI: 10.1002/chem.201904975] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/04/2020] [Indexed: 12/15/2022]
Abstract
Novel functions emerge from novel structures. To develop efficient catalytic systems for challenging chemical transformations, chemists often seek inspirations from enzymatic catalysis. A large number of iron complexes supported by nitrogen-rich multidentate ligands have thus been developed to mimic oxo-transfer reactivity of dioxygen-activating metalloenzymes. Such efforts have significantly advanced our understanding of the reaction mechanisms by trapping key intermediates and elucidating their geometric and electronic properties. Critical to the success of this biomimetic approach is the design and synthesis of elaborate ligand systems to balance the thermodynamic stability, structural adaptability, and chemical reactivity. In this Concept article, representative design strategies for biomimetic atom-transfer chemistry are discussed from the perspectives of "ligand builders". Emphasis is placed on how the primary coordination sphere is constructed, and how it can be elaborated further by rational design for desired functions.
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Affiliation(s)
- Hyunchang Park
- Department of Chemistry, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Korea
| | - Dongwhan Lee
- Department of Chemistry, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Korea
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17
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Guo F, Chai L, Zhang S, Yu H, Liu W, Kepp KP, Ji L. Computational Biotransformation Profile of Emerging Phenolic Pollutants by Cytochromes P450: Phenol-Coupling Mechanism. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:2902-2912. [PMID: 31967796 DOI: 10.1021/acs.est.9b06897] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Phenols are ubiquitous environmental pollutants, whose biotransformation involving phenol coupling catalyzed by cytochromes P450 may produce more lipophilic and toxic metabolites. Density functional theory (DFT) computations were performed to explore the debated phenol-coupling mechanisms, taking triclosan as a model substrate. We find that a diradical pathway facilitated by compound I and protonated compound II of P450 is favored vs alternative radical addition or electron-transfer mechanisms. The identified diradical coupling resembles a "two-state reactivity" from compound I characterized by significantly high rebound barriers of the phenoxy radicals, which can be formulated into three equations for calculating the ratio [coupling]/[hydroxylation]. A higher barrier for rebound than for H-abstraction in high-spin triclosan can facilitate the phenoxy radical dissociation and thus enable phenol coupling, while H-abstraction/radical rebound causing phenol hydroxylation via minor rebound barriers mostly occurs via the low-spin state. Therefore, oxidation of triclosan by P450 fits the first equation with a ratio [coupling]/[hydroxylation] of 1:4, consistent with experimental data indicating different extents of triclosan coupling (6-40%). The high rebound barrier of phenoxy radicals, as a key for the mechanistic identification of phenol coupling vs hydroxylation, originates from their weak electron donor ability due to spin aromatic delocalization. We envision that the revealed mechanism can be extended to the cross-coupling reactions between different phenolic pollutants, and the coupling reactions of several other aromatic pollutants, to infer unknown metabolites.
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Affiliation(s)
- Fangjie Guo
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Lihong Chai
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Shubin Zhang
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China
- Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Haiying Yu
- College of Geography and Environmental Sciences, Zhejiang Normal University, Yingbin Avenue 688, Jinhua 321004, P. R. China
| | - Weiping Liu
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
| | - Kasper P Kepp
- DTU Chemistry, Technical University of Denmark, Building 206, Kgs. Lyngby DK-2800, Denmark
| | - Li Ji
- College of Environmental and Resource Sciences, Zhejiang University, Yuhangtang Road 866, Hangzhou 310058, China
- Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
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18
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Chaturvedi S, Ramanan R, Lehnert N, Schofield CJ, Karabencheva-Christova TG, Christov CZ. Catalysis by the Non-Heme Iron(II) Histone Demethylase PHF8 Involves Iron Center Rearrangement and Conformational Modulation of Substrate Orientation. ACS Catal 2020; 10:1195-1209. [PMID: 31976154 PMCID: PMC6970271 DOI: 10.1021/acscatal.9b04907] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 12/10/2019] [Indexed: 02/07/2023]
Abstract
PHF8 (KDM7B) is a human non-heme 2-oxoglutarate (2OG) JmjC domain oxygenase that catalyzes the demethylation of the di/mono-Nε-methylated K9 residue of histone H3. Altered PHF8 activity is linked to genetic diseases and cancer; thus, it is an interesting target for epigenetic modulation. We describe the use of combined quantum mechanics/molecular mechanics (QM/MM) and molecular dynamics (MD) simulations to explore the mechanism of PHF8, including dioxygen activation, 2OG binding modes, and substrate demethylation steps. A PHF8 crystal structure manifests the 2OG C-1 carboxylate bound to iron in a nonproductive orientation, i.e., trans to His247. A ferryl-oxo intermediate formed by activating dioxygen bound to the vacant site in this complex would be nonproductive, i.e., "off-line" with respect to reaction with Nε-methylated K9. We show rearrangement of the "off-line" ferryl-oxo intermediate to a productive "in-line" geometry via a solvent exchange reaction (called "ferryl-flip") is energetically unfavorable. The calculations imply that movement of the 2OG C-1 carboxylate prior to dioxygen binding at a five-coordination stage in catalysis proceeds with a low barrier, suggesting that two possible 2OG C-1 carboxylate geometries can coexist at room temperature. We explored alternative mechanisms for hydrogen atom transfer and show that second sphere interactions orient the Nε-methylated lysine in a conformation where hydrogen abstraction from a methyl C-H bond is energetically more favorable than hydrogen abstraction from the N-H bond of the protonated Nε-methyl group. Using multiple HAT reaction path calculations, we demonstrate the crucial role of conformational flexibility in effective hydrogen transfer. Subsequent hydroxylation occurs through a rebound mechanism, which is energetically preferred compared to desaturation, due to second sphere interactions. The overall mechanistic insights reveal the crucial role of iron-center rearrangement, second sphere interactions, and conformational flexibility in PHF8 catalysis and provide knowledge useful for the design of mechanism-based PHF8 inhibitors.
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Affiliation(s)
- Shobhit
S. Chaturvedi
- Department
of Chemistry, Michigan Technological University, Houghton, Michigan 49931, United States
| | - Rajeev Ramanan
- Department
of Chemistry, Michigan Technological University, Houghton, Michigan 49931, United States
| | - Nicolai Lehnert
- Department
of Chemistry and Department of Biophysics, University of Michigan, Ann Arbor, Michigan 48109, United States
| | | | | | - Christo Z. Christov
- Department
of Chemistry, Michigan Technological University, Houghton, Michigan 49931, United States
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19
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Massie AA, Denler MC, Singh R, Sinha A, Nordlander E, Jackson TA. Structural Characterization of a Series of N5-Ligated Mn IV -Oxo Species. Chemistry 2020; 26:900-912. [PMID: 31693757 PMCID: PMC7388070 DOI: 10.1002/chem.201904434] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 10/23/2019] [Indexed: 11/05/2022]
Abstract
Analysis of extended X-ray absorption fine structure (EXAFS) data for the MnIV -oxo complexes [MnIV (O)(DMM N4py)]2+ , [MnIV (O)(2pyN2B)]2+ , and [MnIV (O)(2pyN2Q)]2+ (DMM N4py=N,N-bis(4-methoxy-3,5-dimethyl-2-pyridylmethyl)-N-bis(2-pyridyl)methylamine; 2pyN2B=(N-bis(1-methyl-2-benzimidazolyl)methyl-N-(bis-2-pyridylmethyl)amine, and 2pyN2Q=N,N-bis(2-pyridyl)-N,N-bis(2-quinolylmethyl)methanamine) afforded Mn=O and Mn-N bond lengths. The Mn=O distances for [MnIV (O)(DMM N4py)]2+ and [MnIV (O)(2pyN2B)]2+ are 1.72 and 1.70 Å, respectively. In contrast, the Mn=O distance for [MnIV (O)(2pyN2Q)]2+ was significantly longer (1.76 Å). We attribute this long distance to sample heterogeneity, which is reasonable given the reduced stability of [MnIV (O)(2pyN2Q)]2+ . The Mn=O distances for [MnIV (O)(DMM N4py)]2+ and [MnIV (O)(2pyN2B)]2+ could only be well-reproduced using DFT-derived models that included strong hydrogen-bonds between second-sphere solvent 2,2,2-trifluoroethanol molecules and the oxo ligand. These results suggest an important role for the 2,2,2-trifluoroethanol solvent in stabilizing MnIV -oxo adducts. The DFT methods were extended to investigate the structure of the putative [MnIV (O)(N4py)]2+ ⋅(HOTf)2 adduct. These computations suggest that a MnIV -hydroxo species is most consistent with the available experimental data.
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Affiliation(s)
- Allyssa A. Massie
- The University of Kansas, Department of Chemistry and Center for Environmentally Beneficial Catalysis, 1567 Irving Hill Road, Lawrence, KS 66045, USA
| | - Melissa C. Denler
- The University of Kansas, Department of Chemistry and Center for Environmentally Beneficial Catalysis, 1567 Irving Hill Road, Lawrence, KS 66045, USA
| | - Reena Singh
- Lund University, Chemical Physics, Department of Chemistry, Box 124, SE-221 00 Lund, Sweden
| | - Arup Sinha
- Lund University, Chemical Physics, Department of Chemistry, Box 124, SE-221 00 Lund, Sweden
- Department of Chemistry, School of Advanced Science, Vellore Institute of Technology, Vellore - 632014 Tamil Nadu, India
| | - Ebbe Nordlander
- Lund University, Chemical Physics, Department of Chemistry, Box 124, SE-221 00 Lund, Sweden
| | - Timothy A. Jackson
- The University of Kansas, Department of Chemistry and Center for Environmentally Beneficial Catalysis, 1567 Irving Hill Road, Lawrence, KS 66045, USA
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20
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Fukuzumi S, Cho KB, Lee YM, Hong S, Nam W. Mechanistic dichotomies in redox reactions of mononuclear metal–oxygen intermediates. Chem Soc Rev 2020; 49:8988-9027. [DOI: 10.1039/d0cs01251c] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This review article focuses on various mechanistic dichotomies in redox reactions of metal–oxygen intermediates with the emphasis on understanding and controlling their redox reactivity from experimental and theoretical points of view.
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Affiliation(s)
- Shunichi Fukuzumi
- Department of Chemistry and Nano Science
- Ewha Womans University
- Seoul 03760
- Korea
- Graduate School of Science and Engineering
| | - Kyung-Bin Cho
- Department of Chemistry
- Jeonbuk National University
- Jeonju 54896
- Korea
| | - Yong-Min Lee
- Department of Chemistry and Nano Science
- Ewha Womans University
- Seoul 03760
- Korea
| | - Seungwoo Hong
- Department of Chemistry
- Sookmyung Women's University
- Seoul 04310
- Korea
| | - Wonwoo Nam
- Department of Chemistry and Nano Science
- Ewha Womans University
- Seoul 03760
- Korea
- School of Chemistry and Chemical Engineering
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21
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Liu Y, You T, Wang HX, Tang Z, Zhou CY, Che CM. Iron- and cobalt-catalyzed C(sp3)–H bond functionalization reactions and their application in organic synthesis. Chem Soc Rev 2020; 49:5310-5358. [DOI: 10.1039/d0cs00340a] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This review highlights the developments in iron and cobalt catalyzed C(sp3)–H bond functionalization reactions with emphasis on their applications in organic synthesis, i.e. natural products and pharmaceuticals synthesis and/or modification.
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Affiliation(s)
- Yungen Liu
- Department of Chemistry
- Southern University of Science and Technology
- Shenzhen
- P. R. China
| | - Tingjie You
- Department of Chemistry
- State Key Laboratory of Synthetic Chemistry
- The University of Hong Kong
- Hong Kong
- P. R. China
| | - Hai-Xu Wang
- Department of Chemistry
- State Key Laboratory of Synthetic Chemistry
- The University of Hong Kong
- Hong Kong
- P. R. China
| | - Zhou Tang
- Department of Chemistry
- State Key Laboratory of Synthetic Chemistry
- The University of Hong Kong
- Hong Kong
- P. R. China
| | - Cong-Ying Zhou
- Department of Chemistry
- State Key Laboratory of Synthetic Chemistry
- The University of Hong Kong
- Hong Kong
- P. R. China
| | - Chi-Ming Che
- Department of Chemistry
- Southern University of Science and Technology
- Shenzhen
- P. R. China
- Department of Chemistry
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22
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Sabenya G, Gamba I, Gómez L, Clémancey M, Frisch JR, Klinker EJ, Blondin G, Torelli S, Que L, Martin-Diaconescu V, Latour JM, Lloret-Fillol J, Costas M. Octahedral iron(iv)-tosylimido complexes exhibiting single electron-oxidation reactivity. Chem Sci 2019; 10:9513-9529. [PMID: 32055323 PMCID: PMC6979323 DOI: 10.1039/c9sc02526j] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 08/17/2019] [Indexed: 11/28/2022] Open
Abstract
High valent iron species are very reactive molecules involved in oxidation reactions of relevance to biology and chemical synthesis. Herein we describe iron(iv)-tosylimido complexes [FeIV(NTs)(MePy2tacn)](OTf)2 (1(IV)[double bond, length as m-dash]NTs) and [FeIV(NTs)(Me2(CHPy2)tacn)](OTf)2 (2(IV)[double bond, length as m-dash]NTs), (MePy2tacn = N-methyl-N,N-bis(2-picolyl)-1,4,7-triazacyclononane, and Me2(CHPy2)tacn = 1-(di(2-pyridyl)methyl)-4,7-dimethyl-1,4,7-triazacyclononane, Ts = Tosyl). 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs are rare examples of octahedral iron(iv)-imido complexes and are isoelectronic analogues of the recently described iron(iv)-oxo complexes [FeIV(O)(L)]2+ (L = MePy2tacn and Me2(CHPy2)tacn, respectively). 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs are metastable and have been spectroscopically characterized by HR-MS, UV-vis, 1H-NMR, resonance Raman, Mössbauer, and X-ray absorption (XAS) spectroscopy as well as by DFT computational methods. Ferric complexes [FeIII(HNTs)(L)]2+, 1(III)-NHTs (L = MePy2tacn) and 2(III)-NHTs (L = Me2(CHPy2)tacn) have been isolated after the decay of 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs in solution, spectroscopically characterized, and the molecular structure of [FeIII(HNTs)(MePy2tacn)](SbF6)2 determined by single crystal X-ray diffraction. Reaction of 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs with different p-substituted thioanisoles results in the transfer of the tosylimido moiety to the sulphur atom producing sulfilimine products. In these reactions, 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs behave as single electron oxidants and Hammett analyses of reaction rates evidence that tosylimido transfer is more sensitive than oxo transfer to charge effects. In addition, reaction of 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs with hydrocarbons containing weak C-H bonds results in the formation of 1(III)-NHTs and 2(III)-NHTs respectively, along with the oxidized substrate. Kinetic analyses indicate that reactions proceed via a mechanistically unusual HAT reaction, where an association complex precedes hydrogen abstraction.
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Affiliation(s)
- Gerard Sabenya
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
| | - Ilaria Gamba
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
| | - Laura Gómez
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
| | - Martin Clémancey
- Univ. Grenoble-Alpes , CNRS , CEA , IRIG , DIESE , CBM , Grenoble 38000 , France
| | - Jonathan R Frisch
- Department of Chemistry , University of Minnesota , Pleasant Str 207 , Minneapolis , Minnesota , USA
| | - Eric J Klinker
- Department of Chemistry , University of Minnesota , Pleasant Str 207 , Minneapolis , Minnesota , USA
| | - Geneviève Blondin
- Univ. Grenoble-Alpes , CNRS , CEA , IRIG , DIESE , CBM , Grenoble 38000 , France
| | - Stéphane Torelli
- Univ. Grenoble-Alpes , CNRS , CEA , IRIG , DIESE , CBM , Grenoble 38000 , France
| | - Lawrence Que
- Department of Chemistry , University of Minnesota , Pleasant Str 207 , Minneapolis , Minnesota , USA
| | - Vlad Martin-Diaconescu
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
- Institute of Chemical Research of Catalonia (ICIQ) , The Barcelona Institute of Science and Technology , Avinguda Països Catalans 16 , 43007 Tarragona , Spain .
| | - Jean-Marc Latour
- Univ. Grenoble-Alpes , CNRS , CEA , IRIG , DIESE , CBM , Grenoble 38000 , France
| | - Julio Lloret-Fillol
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
- Institute of Chemical Research of Catalonia (ICIQ) , The Barcelona Institute of Science and Technology , Avinguda Països Catalans 16 , 43007 Tarragona , Spain .
- Catalan Institution for Research and Advanced Studies (ICREA) , Passeig Lluïs Companys, 23 , 08010 , Barcelona , Spain
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
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Terencio T, Andris E, Gamba I, Srnec M, Costas M, Roithová J. Chemoselectivity in the Oxidation of Cycloalkenes with a Non-Heme Iron(IV)-Oxo-Chloride Complex: Epoxidation vs. Hydroxylation Selectivity. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:1923-1933. [PMID: 31399940 PMCID: PMC6805805 DOI: 10.1007/s13361-019-02251-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 05/15/2019] [Accepted: 05/15/2019] [Indexed: 06/10/2023]
Abstract
We report and analyze chemoselectivity in the gas phase reactions of cycloalkenes (cyclohexene, cycloheptene, cis-cyclooctene, 1,4-cyclohexadiene) with a non-heme iron(IV)-oxo complex [(PyTACN)Fe(O)(Cl)]+, which models the active species in iron-dependent halogenases. Unlike in the halogenases, we did not observe any chlorination of the substrate. However, we observed two other reaction pathways: allylic hydrogen atom transfer (HAT) and alkene epoxidation. The HAT is clearly preferred in the case of 1,4-cyclohexadiene, both pathways have comparable reaction rates in reaction with cyclohexene, and epoxidation is strongly favored in reactions with cycloheptene and cis-cyclooctene. This preference for epoxidation differs from the reactivity of iron(IV)-oxo complexes in the condensed phase, where HAT usually prevails. To understand the observed selectivity, we analyze effects of the substrate, spin state, and solvation. Our DFT and CASPT2 calculations suggest that all the reactions occur on the quintet potential energy surface. The DFT-calculated energies of the transition states for the epoxidation and hydroxylation pathways explain the observed chemoselectivity. The SMD implicit solvation model predicts the relative increase of the epoxidation barriers with solvent polarity, which explains the clear preference of HAT in the condensed phase.
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Affiliation(s)
- Thibault Terencio
- Department of Organic Chemistry, Faculty of Science, Charles University, Hlavova 2030/8, 128 43, Prague 2, Czech Republic
- School of Chemical Science and Engineering, Yachay Tech University, 100650, Yachay City of Knowledge, Urcuqui, Ecuador
| | - Erik Andris
- Department of Organic Chemistry, Faculty of Science, Charles University, Hlavova 2030/8, 128 43, Prague 2, Czech Republic
| | - Ilaria Gamba
- Departament de Quimica and Institute of Computational Chemistry and Catalysis (IQCC), University of Girona, Campus Montilivi, 17071, Girona, Spain
| | - Martin Srnec
- J. Heyrovsky Institute of Physical Chemistry of the CAS, v. v. i., Dolejškova 2155/3, 182 23, Prague 8, Czech Republic.
| | - Miquel Costas
- Departament de Quimica and Institute of Computational Chemistry and Catalysis (IQCC), University of Girona, Campus Montilivi, 17071, Girona, Spain.
| | - Jana Roithová
- Department of Organic Chemistry, Faculty of Science, Charles University, Hlavova 2030/8, 128 43, Prague 2, Czech Republic.
- Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ, Nijmegen, Netherlands.
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Dantignana V, Serrano-Plana J, Draksharapu A, Magallón C, Banerjee S, Fan R, Gamba I, Guo Y, Que L, Costas M, Company A. Spectroscopic and Reactivity Comparisons between Nonheme Oxoiron(IV) and Oxoiron(V) Species Bearing the Same Ancillary Ligand. J Am Chem Soc 2019; 141:15078-15091. [PMID: 31469954 DOI: 10.1021/jacs.9b05758] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This work directly compares the spectroscopic and reactivity properties of an oxoiron(IV) and an oxoiron(V) complex that are supported by the same neutral tetradentate N-based PyNMe3 ligand. A complete spectroscopic characterization of the oxoiron(IV) species (2) reveals that this compound exists as a mixture of two isomers. The reactivity of the thermodynamically more stable oxoiron(IV) isomer (2b) is directly compared to that exhibited by the previously reported 1e--oxidized analogue [FeV(O)(OAc)(PyNMe3)]2+ (3). Our data indicates that 2b is 4 to 5 orders of magnitude slower than 3 in hydrogen atom transfer (HAT) from C-H bonds. The origin of this huge difference lies in the strength of the O-H bond formed after HAT by the oxoiron unit, the O-H bond derived from 3 being about 20 kcal·mol-1 stronger than that from 2b. The estimated bond strength of the FeIVO-H bond of 100 kcal·mol-1 is very close to the reported values for highly active synthetic models of compound I of cytochrome P450. In addition, this comparative study provides direct experimental evidence that the lifetime of the carbon-centered radical that forms after the initial HAT by the high valent oxoiron complex depends on the oxidation state of the nascent Fe-OH complex. Complex 2b generates long-lived carbon-centered radicals that freely diffuse in solution, while 3 generates short-lived caged radicals that rapidly form product C-OH bonds, so only 3 engages in stereoretentive hydroxylation reactions. Thus, the oxidation state of the iron center modulates not only the rate of HAT but also the rate of ligand rebound.
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Affiliation(s)
- Valeria Dantignana
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química , Universitat de Girona , C/M. Aurèlia Capmany 69 , 17003 Girona , Catalonia , Spain
| | - Joan Serrano-Plana
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química , Universitat de Girona , C/M. Aurèlia Capmany 69 , 17003 Girona , Catalonia , Spain
| | - Apparao Draksharapu
- Department of Chemistry and Center for Metals in Biocatalysis , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | - Carla Magallón
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química , Universitat de Girona , C/M. Aurèlia Capmany 69 , 17003 Girona , Catalonia , Spain
| | - Saikat Banerjee
- Department of Chemistry and Center for Metals in Biocatalysis , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | - Ruixi Fan
- Department of Chemistry , Carnegie Mellon University , 4400 Fifth Avenue , Pittsburgh , Pennsylvania 15213 , United States
| | - Ilaria Gamba
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química , Universitat de Girona , C/M. Aurèlia Capmany 69 , 17003 Girona , Catalonia , Spain
| | - Yisong Guo
- Department of Chemistry , Carnegie Mellon University , 4400 Fifth Avenue , Pittsburgh , Pennsylvania 15213 , United States
| | - Lawrence Que
- Department of Chemistry and Center for Metals in Biocatalysis , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química , Universitat de Girona , C/M. Aurèlia Capmany 69 , 17003 Girona , Catalonia , Spain
| | - Anna Company
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química , Universitat de Girona , C/M. Aurèlia Capmany 69 , 17003 Girona , Catalonia , Spain
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25
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Abdi Z, Bagheri R, Song Z, Najafpour MM. Water oxidation by Ferritin: A semi-natural electrode. Sci Rep 2019; 9:11499. [PMID: 31395911 PMCID: PMC6687787 DOI: 10.1038/s41598-019-47661-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 07/16/2019] [Indexed: 02/07/2023] Open
Abstract
Ferritin is a protein (ca. 12 nm) with a central pocket of 6 nm diameter, and hydrated iron oxide stored in this central cavity of this protein. The protein shell has a complicated structure with 24 subunits. Transmission electron microscopy images of ferritin showed nanosized iron oxides (ca. 4-6 nm) in the protein structure. In high-resolution transmission electron microscopy images of the iron core, d-spacings of 2.5-2.6 Å were observed, which is corresponded to d-spacings of ferrihydrite crystal structure. Our experiments showed that at pH 11, the modified electrode by this biomolecule is active for water oxidation (turnover frequency: 0.001 s-1 at 1.7 V). Using affected by bacteria, we showed that Fe ions in the structure of ferritin are critical for water oxidation.
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Affiliation(s)
- Zahra Abdi
- Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, 45137-66731, Iran
| | - Robabeh Bagheri
- Surface Protection Research Group, Surface Department, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, 519 Zhuangshi Road, Ningbo, 315201, China
| | - Zhenlun Song
- Surface Protection Research Group, Surface Department, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, 519 Zhuangshi Road, Ningbo, 315201, China
| | - Mohammad Mahdi Najafpour
- Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, 45137-66731, Iran. .,Center of Climate Change and Global Warming, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, 45137-66731, Iran. .,Research Center for Basic Sciences & Modern Technologies (RBST), Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, 45137-66731, Iran.
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26
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Nandy A, Zhu J, Janet JP, Duan C, Getman RB, Kulik HJ. Machine Learning Accelerates the Discovery of Design Rules and Exceptions in Stable Metal–Oxo Intermediate Formation. ACS Catal 2019. [DOI: 10.1021/acscatal.9b02165] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
| | - Jiazhou Zhu
- Department of Chemical & Biomolecular Engineering, Clemson University, Clemson, South Carolina 29634, United States
| | | | | | - Rachel B. Getman
- Department of Chemical & Biomolecular Engineering, Clemson University, Clemson, South Carolina 29634, United States
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27
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Singh R, Ganguly G, Malinkin SO, Demeshko S, Meyer F, Nordlander E, Paine TK. A Mononuclear Nonheme Iron(IV)-Oxo Complex of a Substituted N4Py Ligand: Effect of Ligand Field on Oxygen Atom Transfer and C–H Bond Cleavage Reactivity. Inorg Chem 2019; 58:1862-1876. [DOI: 10.1021/acs.inorgchem.8b02577] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Reena Singh
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Gaurab Ganguly
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
| | - Sergey O. Malinkin
- Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Serhiy Demeshko
- Universität
Göttingen, Institut für Anorganische Chemie, Tammanstrasse 4, D-37077 Göttingen, Germany
| | - Franc Meyer
- Universität
Göttingen, Institut für Anorganische Chemie, Tammanstrasse 4, D-37077 Göttingen, Germany
| | - Ebbe Nordlander
- Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-22100 Lund, Sweden
| | - Tapan Kanti Paine
- School of Chemical Sciences, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032, India
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28
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Mendonça AAS, Coelho CM, Veloso MP, Caldas IS, Gonçalves RV, Teixeira AL, de Miranda AS, Novaes RD. Relevance of Trypanothione Reductase Inhibitors on Trypanosoma cruzi Infection: A Systematic Review, Meta-Analysis, and In Silico Integrated Approach. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:8676578. [PMID: 30473742 PMCID: PMC6220389 DOI: 10.1155/2018/8676578] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 08/14/2018] [Indexed: 02/08/2023]
Abstract
Due to the rudimentary antioxidant defenses in Trypanosoma cruzi, disruptors of redox balance are promising candidates for new antitrypanosomal drugs. We developed an integrated model based on systematic review, meta-analyses, and molecular modeling to evaluate the effect of trypanothione reductase (TR) inhibitors in T. cruzi infections. Our findings indicated that the TR inhibitors analyzed were effective in reducing parasitemia and mortality due to Trypanosoma cruzi infection in animal models. The most investigated drugs (clomipramine and thioridazine) showed no beneficial effects on the occurrence of infection-related electrocardiographic abnormalities or the affinity and density of cardiac β-adrenergic receptors. The affinity between the tested ligands and the active site of TR was confirmed by molecular docking. However, the molecular affinity score was unable to explain TR inhibition and T. cruzi death in vitro or the antiparasitic potential of these drugs when tested in preclinical models of T. cruzi infection. The divergence of in silico, in vitro, and in vivo findings indicated that the anti-T. cruzi effects of the analyzed drugs were not restricted to TR inhibition. As in vivo studies on TR inhibitors are still scarce and exhibit methodological limitations, mechanistic and highly controlled studies are required to improve the quality of evidence.
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Affiliation(s)
- Andréa Aparecida Santos Mendonça
- Institute of Biomedical Sciences, Federal University of Alfenas, Alfenas, 37130-001 Minas Gerais, Brazil
- Department of Structural Biology, Federal University of Alfenas, Alfenas, 37130-001 Minas Gerais, Brazil
| | - Camila Morais Coelho
- Faculty of Pharmaceutical Sciences, Federal University of Alfenas, Alfenas, 37130-001 Minas Gerais, Brazil
| | - Marcia Paranho Veloso
- Faculty of Pharmaceutical Sciences, Federal University of Alfenas, Alfenas, 37130-001 Minas Gerais, Brazil
| | - Ivo Santana Caldas
- Institute of Biomedical Sciences, Federal University of Alfenas, Alfenas, 37130-001 Minas Gerais, Brazil
- Department of Pathology and Parasitology, Federal University of Alfenas, Alfenas, 37130-001 Minas Gerais, Brazil
| | | | - Antônio Lucio Teixeira
- Interdisciplinary Laboratory of Medical Investigation, School of Medicine, Federal University of Minas Gerais, Belo Horizonte, 30130-100 Minas Gerais, Brazil
| | - Aline Silva de Miranda
- Interdisciplinary Laboratory of Medical Investigation, School of Medicine, Federal University of Minas Gerais, Belo Horizonte, 30130-100 Minas Gerais, Brazil
- Institute of Biological Sciences, Department of Morphology, Federal University of Minas Gerais, Belo Horizonte, 30130-100 Minas Gerais, Brazil
| | - Rômulo Dias Novaes
- Institute of Biomedical Sciences, Federal University of Alfenas, Alfenas, 37130-001 Minas Gerais, Brazil
- Department of Structural Biology, Federal University of Alfenas, Alfenas, 37130-001 Minas Gerais, Brazil
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29
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Brewer SM, Palacios PM, Johnston HM, Pierce BS, Green KN. Isolation and identification of the pre-catalyst in iron-catalyzed direct arylation of pyrrole with phenylboronic acid. Inorganica Chim Acta 2018. [DOI: 10.1016/j.ica.2018.03.036] [Citation(s) in RCA: 11] [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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30
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Schaub S, Miska A, Becker J, Zahn S, Mollenhauer D, Sakshath S, Schünemann V, Schindler S. Synthesis of an Iron(IV) Aqua-Oxido Complex Using Ozone as an Oxidant. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201800475] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Stefan Schaub
- Institut für Anorganische und Analytische Chemie; Justus-Liebig-Universität Gießen; Heinrich-Buff-Ring 17 35392 Gießen Germany
| | - Andreas Miska
- Institut für Anorganische und Analytische Chemie; Justus-Liebig-Universität Gießen; Heinrich-Buff-Ring 17 35392 Gießen Germany
| | - Jonathan Becker
- Institut für Anorganische und Analytische Chemie; Justus-Liebig-Universität Gießen; Heinrich-Buff-Ring 17 35392 Gießen Germany
| | - Stefan Zahn
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie; Universität Leipzig; Linnéstraße 2 04103 Leipzig Germany
| | - Doreen Mollenhauer
- Institut für Physikalische Chemie; Justus-Liebig-Universität Gießen; Heinrich-Buff-Ring 17 35392 Gießen Germany
| | - Sadashivaiah Sakshath
- Fachbereich Physik; Technische Universität Kaiserslautern; Schrödinger Straße 46 67663 Kaiserslautern Germany
| | - Volker Schünemann
- Fachbereich Physik; Technische Universität Kaiserslautern; Schrödinger Straße 46 67663 Kaiserslautern Germany
| | - Siegfried Schindler
- Institut für Anorganische und Analytische Chemie; Justus-Liebig-Universität Gießen; Heinrich-Buff-Ring 17 35392 Gießen Germany
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Schaub S, Miska A, Becker J, Zahn S, Mollenhauer D, Sakshath S, Schünemann V, Schindler S. Synthesis of an Iron(IV) Aqua-Oxido Complex Using Ozone as an Oxidant. Angew Chem Int Ed Engl 2018. [PMID: 29520940 DOI: 10.1002/anie.201800475] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The iron(IV) oxido complex [(tmc)Fe=O(OTf)]OTf with the macrocyclic ligand 1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclo-tetradecane (tmc) has been synthesized using ozone as an oxidant. By adding water to this compound the complex [(H2 O)(tmc)Fe=O)](OTf)2 could be prepared. This complex is important in regard to a better understanding of the reactivity of FeIV oxido complexes. Mössbauer measurements using the solid compound showed an isomer shift of δ=0.19 mm s-1 and a quadrupole splitting ΔEQ =1.38 mm s-1 , confirming the high-valent FeIV state. DFT calculations were performed and led to an assignment of triplet spin multiplicity. Crystallographic characterization of [(H2 O)(tmc)Fe=O)](OTf)2 as well as of starting materials [(tmc)Fe(CH3 CN)](OTf)2 and [(tmc)Fe(OTf)]OTf together with previous results strongly suggest that [(H2 O)(tmc)Fe=O)](OTf)2 was formed similar to the oxido-hydroxido tautomerism analogous to heme systems.
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Affiliation(s)
- Stefan Schaub
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 17, 35392, Gießen, Germany
| | - Andreas Miska
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 17, 35392, Gießen, Germany
| | - Jonathan Becker
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 17, 35392, Gießen, Germany
| | - Stefan Zahn
- Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstraße 2, 04103, Leipzig, Germany
| | - Doreen Mollenhauer
- Institut für Physikalische Chemie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 17, 35392, Gießen, Germany
| | - Sadashivaiah Sakshath
- Fachbereich Physik, Technische Universität Kaiserslautern, Schrödinger Straße 46, 67663, Kaiserslautern, Germany
| | - Volker Schünemann
- Fachbereich Physik, Technische Universität Kaiserslautern, Schrödinger Straße 46, 67663, Kaiserslautern, Germany
| | - Siegfried Schindler
- Institut für Anorganische und Analytische Chemie, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 17, 35392, Gießen, Germany
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32
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Song X, Lu J, Lai W. Mechanistic insights into dioxygen activation, oxygen atom exchange and substrate epoxidation by AsqJ dioxygenase from quantum mechanical/molecular mechanical calculations. Phys Chem Chem Phys 2018; 19:20188-20197. [PMID: 28726913 DOI: 10.1039/c7cp02687k] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Herein, we use in-protein quantum mechanical/molecular mechanical (QM/MM) calculations to elucidate the mechanism of dioxygen activation, oxygen atom exchange and substrate epoxidation processes by AsqJ, an FeII/α-ketoglutarate-dependent dioxygenase (α-KGD) using a 2-His-1-Asp facial triad. Our results demonstrated that the whole reaction proceeds through a quintet surface. The dioxygen activation by AsqJ leads to a quintet penta-coordinated FeIV-oxo species, which has a square pyramidal geometry with the oxo group trans to His134. This penta-coordinated FeIV-oxo species is not the reactive one in the substrate epoxidation reaction since its oxo group is pointing away from the target C[double bond, length as m-dash]C bond. Instead, it can undergo the oxo group isomerization followed by water binding or the water binding followed by oxygen atom exchange to form the reactive hexa-coordinated FeIV-oxo species with the oxo group trans to His211. The calculated parameters of Mössbauer spectra for this hexa-coordinated FeIV-oxo intermediate are in excellent agreement with the experimental values, suggesting that it is most likely the experimentally trapped species. The calculated energetics indicated that the rate-limiting step is the substrate C[double bond, length as m-dash]C bond activation. This work improves our understanding of the dioxygen activation by α-KGD and provides important structural information about the reactive FeIV-oxo species.
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Affiliation(s)
- Xudan Song
- Department of Chemistry, Renmin University of China, Beijing, 100872, China.
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Klein JEMN, Draksharapu A, Shokri A, Cramer CJ, Que L. On the Lewis Acidity of the Oxoiron(IV) Unit in a Tetramethylcyclam Complex. Chemistry 2017; 24:5373-5378. [PMID: 29205555 DOI: 10.1002/chem.201704977] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Indexed: 11/08/2022]
Abstract
The correlation between oxidation state and Lewis acidity is well established for hexaquairon complexes in the +II and +III oxidation state, in which the higher oxidation state leads to a lower pKa for the bound H2 O ligand. This article addresses the Lewis acidity of the oxoiron(IV) complex [FeIV (O)(TMC)(OH2 )]2+ (1-OH2 ; TMC=1,4,8,11-tetramethylcyclam) by determining the pKa of the H2 O ligand. We establish that 1-OH2 has a pKa of 6.9±0.5, a value that falls in between those found for [FeIII (OH2 )6 ]3+ and [FeII (OH2 )6 ]2+ . This intermediate value can be readily rationalized by the presence of the highly basic oxide ligand that mitigates the Lewis acidity of the iron(IV) center. Although the oxo ligand occupies only one position in 1-OH2 , anti to all four methyl groups that protrude from the same face of the nonplanar TMC ligand, its conjugate base 1-OH exists as a mixture of syn and anti tautomers, which are related by proton transfer between the oxo and the hydroxo ligands.
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Affiliation(s)
- Johannes E M N Klein
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, 207 Pleasant St. S.E., Minneapolis, Minnesota, 55455, USA.,Present Address: Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747, AG Groningen, The Netherlands
| | - Apparao Draksharapu
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, 207 Pleasant St. S.E., Minneapolis, Minnesota, 55455, USA
| | - Alireza Shokri
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, 207 Pleasant St. S.E., Minneapolis, Minnesota, 55455, USA
| | - Christopher J Cramer
- Department of Chemistry, Supercomputing Institute, and Chemical Theory Center, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota, 55455, USA
| | - Lawrence Que
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, 207 Pleasant St. S.E., Minneapolis, Minnesota, 55455, USA
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Cussó O, Serrano-Plana J, Costas M. Evidence of a Sole Oxygen Atom Transfer Agent in Asymmetric Epoxidations with Fe-pdp Catalysts. ACS Catal 2017. [DOI: 10.1021/acscatal.7b01184] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Olaf Cussó
- QBIS Research Group, Institut de Química
Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17071, Catalonia, Spain
| | - Joan Serrano-Plana
- QBIS Research Group, Institut de Química
Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17071, Catalonia, Spain
| | - Miquel Costas
- QBIS Research Group, Institut de Química
Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Campus Montilivi, Girona E-17071, Catalonia, Spain
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35
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Sabenya G, Lázaro L, Gamba I, Martin-Diaconescu V, Andris E, Weyhermüller T, Neese F, Roithova J, Bill E, Lloret-Fillol J, Costas M. Generation, Spectroscopic, and Chemical Characterization of an Octahedral Iron(V)-Nitrido Species with a Neutral Ligand Platform. J Am Chem Soc 2017; 139:9168-9177. [DOI: 10.1021/jacs.7b00429] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Gerard Sabenya
- Institut
de Química Computacional i Catàlisi (IQCC) and Departament
de Química, Universitat de Girona, Campus Montilivi, E17071 Girona, Catalonia, Spain
| | - Laura Lázaro
- Institut
de Química Computacional i Catàlisi (IQCC) and Departament
de Química, Universitat de Girona, Campus Montilivi, E17071 Girona, Catalonia, Spain
| | - Ilaria Gamba
- Institut
de Química Computacional i Catàlisi (IQCC) and Departament
de Química, Universitat de Girona, Campus Montilivi, E17071 Girona, Catalonia, Spain
| | - Vlad Martin-Diaconescu
- Institut
de Química Computacional i Catàlisi (IQCC) and Departament
de Química, Universitat de Girona, Campus Montilivi, E17071 Girona, Catalonia, Spain
| | - Erik Andris
- Department
of Organic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030/8, 12843 Prague 2, Czech Republic
| | - Thomas Weyhermüller
- Max Planck Institut für Chemische Energiekonversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Frank Neese
- Max Planck Institut für Chemische Energiekonversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Jana Roithova
- Department
of Organic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030/8, 12843 Prague 2, Czech Republic
| | - Eckhard Bill
- Max Planck Institut für Chemische Energiekonversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Julio Lloret-Fillol
- Institute
of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Avinguda Paisos Catalans 16, 43007 Tarragona, Catalonia, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Passeig Lluïs Companys 23, 08010 Barcelona, Spain
| | - Miquel Costas
- Institut
de Química Computacional i Catàlisi (IQCC) and Departament
de Química, Universitat de Girona, Campus Montilivi, E17071 Girona, Catalonia, Spain
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Kupper C, Mondal B, Serrano-Plana J, Klawitter I, Neese F, Costas M, Ye S, Meyer F. Nonclassical Single-State Reactivity of an Oxo-Iron(IV) Complex Confined to Triplet Pathways. J Am Chem Soc 2017; 139:8939-8949. [PMID: 28557448 DOI: 10.1021/jacs.7b03255] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
C-H bond activation mediated by oxo-iron (IV) species represents the key step of many heme and nonheme O2-activating enzymes. Of crucial interest is the effect of spin state of the FeIV(O) unit. Here we report the C-H activation kinetics and corresponding theoretical investigations of an exclusive tetracarbene ligated oxo-iron(IV) complex, [LNHCFeIV(O)(MeCN)]2+ (1). Kinetic traces using substrates with bond dissociation energies (BDEs) up to 80 kcal mol-1 show pseudo-first-order behavior and large but temperature-dependent kinetic isotope effects (KIE 32 at -40 °C). When compared with a topologically related oxo-iron(IV) complex bearing an equatorial N-donor ligand, [LTMCFeIV(O) (MeCN)]2+ (A), the tetracarbene complex 1 is significantly more reactive with second order rate constants k'2 that are 2-3 orders of magnitude higher. UV-vis experiments in tandem with cryospray mass spectrometry evidence that the reaction occurs via formation of a hydroxo-iron(III) complex (4) after the initial H atom transfer (HAT). An extensive computational study using a wave function based multireference approach, viz. complete active space self-consistent field (CASSCF) followed by N-electron valence perturbation theory up to second order (NEVPT2), provided insight into the HAT trajectories of 1 and A. Calculated free energy barriers for 1 reasonably agree with experimental values. Because the strongly donating equatorial tetracarbene pushes the Fe-dx2-y2 orbital above dz2, 1 features a dramatically large quintet-triplet gap of ∼18 kcal/mol compared to ∼2-3 kcal/mol computed for A. Consequently, the HAT process performed by 1 occurs on the triplet surface only, in contrast to complex A reported to feature two-state-reactivity with contributions from both triplet and quintet states. Despite this, the reactive FeIV(O) units in 1 and A undergo the same electronic-structure changes during HAT. Thus, the unique complex 1 represents a pure "triplet-only" ferryl model.
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Affiliation(s)
- Claudia Kupper
- Universität Göttingen , Institut für Anorganische Chemie, Tammannstrasse 4, 37077 Göttingen, Germany
| | - Bhaskar Mondal
- Max-Planck Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Joan Serrano-Plana
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Quimica, Universitat de Girona , Campus Montilivi, E17071 Girona, Catalonia, Spain
| | - Iris Klawitter
- Universität Göttingen , Institut für Anorganische Chemie, Tammannstrasse 4, 37077 Göttingen, Germany
| | - Frank Neese
- Max-Planck Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Quimica, Universitat de Girona , Campus Montilivi, E17071 Girona, Catalonia, Spain
| | - Shengfa Ye
- Max-Planck Institut für Chemische Energiekonversion , Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Franc Meyer
- Universität Göttingen , Institut für Anorganische Chemie, Tammannstrasse 4, 37077 Göttingen, Germany
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Collins TJ, Ryabov AD. Targeting of High-Valent Iron-TAML Activators at Hydrocarbons and Beyond. Chem Rev 2017; 117:9140-9162. [PMID: 28488444 DOI: 10.1021/acs.chemrev.7b00034] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
TAML activators of peroxides are iron(III) complexes. The ligation by four deprotonated amide nitrogens in macrocyclic motifs is the signature of TAMLs where the macrocyclic structures vary considerably. TAML activators are exceptional functional replicas of the peroxidases and cytochrome P450 oxidizing enzymes. In water, they catalyze peroxide oxidation of a broad spectrum of compounds, many of which are micropollutants, compounds that produce undesired effects at low concentrations-as with the enzymes, peroxide is typically activated with near-quantitative efficiency. In nonaqueous solvents such as organic nitriles, the prototype TAML activator gave the structurally authenticated reactive iron(V)oxo units (FeVO), wherein the iron atom is two oxidation equivalents above the FeIII resting state. The iron(V) state can be achieved through the intermediacy of iron(IV) species, which are usually μ-oxo-bridged dimers (FeIVFeIV), and this allows for the reactivity of this potent reactive intermediate to be studied in stoichiometric processes. The present review is primarily focused at the mechanistic features of the oxidation by FeVO of hydrocarbons including cyclohexane. The main topic is preceded by a description of mechanisms of oxidation of thioanisoles by FeVO, because the associated studies provide valuable insight into the ability of FeVO to oxidize organic molecules. The review is opened by a summary of the interconversions between FeIII, FeIVFeIV, and FeVO species, since this information is crucial for interpreting the kinetic data. The highest reactivity in both reaction classes described belongs to FeVO. The resting state FeIII is unreactive oxidatively. Intermediate reactivity is typically found for FeIVFeIV; therefore, kinetic features for these species in interchange and oxidation processes are also reviewed. Examples of using TAML activators for C-H bond cleavage applied to fine organic synthesis conclude the review.
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Affiliation(s)
- Terrence J Collins
- Department of Chemistry, Carnegie Mellon University , 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Alexander D Ryabov
- Department of Chemistry, Carnegie Mellon University , 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
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Xue XS, Ji P, Zhou B, Cheng JP. The Essential Role of Bond Energetics in C-H Activation/Functionalization. Chem Rev 2017; 117:8622-8648. [PMID: 28281752 DOI: 10.1021/acs.chemrev.6b00664] [Citation(s) in RCA: 304] [Impact Index Per Article: 43.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The most fundamental concepts in chemistry are structure, energetics, reactivity and their inter-relationships, which are indispensable for promoting chemistry into a rational science. In this regard, bond energy, the intrinsic determinant directly related to structure and reactivity, should be most essential in serving as a quantitative basis for the design and understanding of organic transformations. Although C-H activation/functionalization have drawn tremendous research attention and flourished during the past decades, understanding the governing rules of bond energetics in these processes is still fragmentary and seems applicable only to limited cases, such as metal-oxo-mediated hydrogen atom abstraction. Despite the complexity of C-H activation/functionalization and the difficulties in measuring bond energies both for the substrates and intermediates, this is definitely a very important issue that should be more generally contemplated. To this end, this review is rooted in the energetic aspects of C-H activation/functionalization, which were previously rarely discussed in detail. Starting with a concise but necessary introduction of various classical methods for measuring heterolytic and homolytic energies for C-H bonds, the present review provides examples that applied the concept and values of C-H bond energy in rationalizing the observations associated with reactivity and/or selectivity in C-H activation/functionalization.
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Affiliation(s)
- Xiao-Song Xue
- State Key Laboratory of Elemento-organic Chemistry, Collaborative Innovation Center of Chemical Science and Engineering, Nankai University , Tianjin, 300071, China
| | - Pengju Ji
- Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University , Beijing, 100084, China
| | - Biying Zhou
- State Key Laboratory of Elemento-organic Chemistry, Collaborative Innovation Center of Chemical Science and Engineering, Nankai University , Tianjin, 300071, China
| | - Jin-Pei Cheng
- Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University , Beijing, 100084, China.,State Key Laboratory of Elemento-organic Chemistry, Collaborative Innovation Center of Chemical Science and Engineering, Nankai University , Tianjin, 300071, China
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Andris E, Navrátil R, Jašík J, Terencio T, Srnec M, Costas M, Roithová J. Chasing the Evasive Fe═O Stretch and the Spin State of the Iron(IV)-Oxo Complexes by Photodissociation Spectroscopy. J Am Chem Soc 2017; 139:2757-2765. [PMID: 28125220 DOI: 10.1021/jacs.6b12291] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We demonstrate the application of infrared photodissocation spectroscopy for determination of the Fe═O stretching frequencies of high-valent iron(IV)-oxo complexes [(L)Fe(O)(X)]2+/+ (L = TMC, N4Py, PyTACN, and X = CH3CN, CF3SO3, ClO4, CF3COO, NO3, N3). We show that the values determined by resonance Raman spectroscopy in acetonitrile solutions are on average 9 cm-1 red-shifted with respect to unbiased gas-phase values. Furthermore, we show the assignment of the spin state of the complexes based on the vibrational modes of a coordinated anion and compare reactivities of various iron(IV)-oxo complexes generated as dications or monocations (bearing an anionic ligand). The coordinated anions can drastically affect the reactivity of the complex and should be taken into account when comparing reactivities of complexes bearing different ligands. Comparison of reactivities of [(PyTACN)Fe(O)(X)]+ generated in different spin states and bearing different anionic ligands X revealed that the nature of anion influences the reactivity more than the spin state. The triflate and perchlorate ligands tend to stabilize the quintet state of [(PyTACN)Fe(O)(X)]+, whereas trifluoroacetate and nitrate stabilize the triplet state of the complex.
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Affiliation(s)
- Erik Andris
- Department of Organic Chemistry, Faculty of Science, Charles University , Hlavova 2030/8, 12843 Prague 2, Czech Republic
| | - Rafael Navrátil
- Department of Organic Chemistry, Faculty of Science, Charles University , Hlavova 2030/8, 12843 Prague 2, Czech Republic
| | - Juraj Jašík
- Department of Organic Chemistry, Faculty of Science, Charles University , Hlavova 2030/8, 12843 Prague 2, Czech Republic
| | - Thibault Terencio
- Department of Organic Chemistry, Faculty of Science, Charles University , Hlavova 2030/8, 12843 Prague 2, Czech Republic
| | - Martin Srnec
- J. Heyrovsky Institute of Physical Chemistry of the CAS , v.v i., Dolejškova 2155/3, 182 23 Prague 8, Czech Republic
| | - Miquel Costas
- Departament de Quimica and Institute of Computational Chemistry and Catalysis (IQCC), University of Girona , Campus Montilivi, Girona 17071, Spain
| | - Jana Roithová
- Department of Organic Chemistry, Faculty of Science, Charles University , Hlavova 2030/8, 12843 Prague 2, Czech Republic
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Bok KH, Lee MM, You GR, Ahn HM, Ryu KY, Kim SJ, Kim Y, Kim C. Synthesis, Characterization, and Catalytic Activities of A Nickel(II) Monoamido-Tetradentate Complex: Evidence For NiIII
-Oxo and NiIV
-Oxo Species. Chemistry 2017; 23:3117-3125. [DOI: 10.1002/chem.201605157] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Kwon Hee Bok
- Department of Fine Chemistry; Seoul National University of Science and Technology; Seoul 139-743 Korea
| | - Myoung Mi Lee
- Department of Fine Chemistry; Seoul National University of Science and Technology; Seoul 139-743 Korea
| | - Ga Rim You
- Department of Fine Chemistry; Seoul National University of Science and Technology; Seoul 139-743 Korea
| | - Hye Mi Ahn
- Department of Fine Chemistry; Seoul National University of Science and Technology; Seoul 139-743 Korea
| | - Ka Young Ryu
- Department of Fine Chemistry; Seoul National University of Science and Technology; Seoul 139-743 Korea
| | - Sung-Jin Kim
- Department of Chemistry and Nano Science; Ewha Womans University; Seoul 120-750 Korea
| | - Youngmee Kim
- Department of Chemistry and Nano Science; Ewha Womans University; Seoul 120-750 Korea
| | - Cheal Kim
- Department of Fine Chemistry; Seoul National University of Science and Technology; Seoul 139-743 Korea
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41
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Oxidation of alkane and alkene moieties with biologically inspired nonheme iron catalysts and hydrogen peroxide: from free radicals to stereoselective transformations. J Biol Inorg Chem 2017; 22:425-452. [DOI: 10.1007/s00775-016-1434-z] [Citation(s) in RCA: 123] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 12/27/2016] [Indexed: 11/26/2022]
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Cho KB, Hirao H, Shaik S, Nam W. To rebound or dissociate? This is the mechanistic question in C-H hydroxylation by heme and nonheme metal-oxo complexes. Chem Soc Rev 2016; 45:1197-210. [PMID: 26690848 DOI: 10.1039/c5cs00566c] [Citation(s) in RCA: 146] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Enzymatic reactions that involve C-H bond activation of alkanes by high-valent iron-oxo species can be explained by the rebound mechanism (RM). Hydroxylation reactions of alkane substrates effected by the reactive compound I (Cpd I) species of cytochrome P450 enzymes are good examples. There was initially little doubt that the rebound paradigm could be carried over in the same form to the arena of synthetic nonheme high-valent iron-oxo or other metal-oxo complexes. However, the active reaction centres of these synthetic systems are not well-caged, in contrast to the active sites of enzymes; therefore, the relative importance of the radical dissociation pathway can become prominent. Indeed, accumulating experimental and theoretical evidence shows that introduction of the non-rebound mechanism (non-RM) is necessary to rationalise the different reactivity patterns observed for synthetic nonheme complexes. In this tutorial review, we discuss several specific examples involving the non-RM while making frequent comparisons to the RM, mainly from the perspective of computational chemistry. We also provide a technical guide to DFT calculations of RM and non-RM and to the interpretations of computational outcomes.
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Affiliation(s)
- Kyung-Bin Cho
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea.
| | - Hajime Hirao
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Republic of Singapore.
| | - Sason Shaik
- Institute of Chemistry and The Lise Meitner-Minerva Center for Computational Quantum Chemistry, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel.
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea.
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Al-hunaiti A, Räisänen M, Repo T. From DNA to catalysis: a thymine-acetate ligated non-heme iron(III) catalyst for oxidative activation of aliphatic C-H bonds. Chem Commun (Camb) 2016; 52:2043-6. [PMID: 26685988 DOI: 10.1039/c5cc07597a] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A non-heme, iron(III)/THA(thymine-1-acetate) catalyst together with H2O2 as an oxidant is efficient in oxidative C-H activation of alkanes. Although having a higher preference for tertiary C-H bonds, the catalyst also oxidizes aliphatic secondary C-H bonds into carbonyl compounds with good to excellent conversions. Based on the site selectivity of the catalyst and our mechanistic studies the reaction proceeds via an Fe-oxo species without long lived carbon centered radicals.
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Affiliation(s)
- Afnan Al-hunaiti
- Department of Chemistry, University of Helsinki, A. I. Virtasen Aukio 1, P.O. Box 55, 00014 University of Helsinki, Finland.
| | - Minnä Räisänen
- Department of Chemistry, University of Helsinki, A. I. Virtasen Aukio 1, P.O. Box 55, 00014 University of Helsinki, Finland.
| | - Timo Repo
- Department of Chemistry, University of Helsinki, A. I. Virtasen Aukio 1, P.O. Box 55, 00014 University of Helsinki, Finland.
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Casadevall C, Codolà Z, Costas M, Lloret-Fillol J. Spectroscopic, Electrochemical and Computational Characterisation of Ru Species Involved in Catalytic Water Oxidation: Evidence for a [Ru(V) (O)(Py2 (Me) tacn)] Intermediate. Chemistry 2016; 22:10111-26. [PMID: 27324949 DOI: 10.1002/chem.201600584] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Indexed: 01/09/2023]
Abstract
A new family of ruthenium complexes based on the N-pentadentate ligand Py2 (Me) tacn (N-methyl-N',N''-bis(2-picolyl)-1,4,7-triazacyclononane) has been synthesised and its catalytic activity has been studied in the water-oxidation (WO) reaction. We have used chemical oxidants (ceric ammonium nitrate and NaIO4 ) to generate the WO intermediates [Ru(II) (OH2 )(Py2 (Me) tacn)](2+) , [Ru(III) (OH2 )(Py2 (Me) tacn)](3+) , [Ru(III) (OH)(Py2 (Me) tacn)](2+) and [Ru(IV) (O)(Py2 (Me) tacn)](2+) , which have been characterised spectroscopically. Their relative redox and pH stability in water has been studied by using UV/Vis and NMR spectroscopies, HRMS and spectroelectrochemistry. [Ru(IV) (O)(Py2 (Me) tacn)](2+) has a long half-life (>48 h) in water. The catalytic cycle of WO has been elucidated by using kinetic, spectroscopic, (18) O-labelling and theoretical studies, and the conclusion is that the rate-determining step is a single-site water nucleophilic attack on a metal-oxo species. Moreover, [Ru(IV) (O)(Py2 (Me) tacn)](2+) is proposed to be the resting state under catalytic conditions. By monitoring Ce(IV) consumption, we found that the O2 evolution rate is redox-controlled and independent of the initial concentration of Ce(IV) . Based on these facts, we propose herein that [Ru(IV) (O)(Py2 (Me) tacn)](2+) is oxidised to [Ru(V) (O)(Py2 (Me) tacn)](2+) prior to attack by a water molecule to give [Ru(III) (OOH)(Py2 (Me) tacn)](2+) . Finally, it is shown that the difference in WO reactivity between the homologous iron and ruthenium [M(OH2 )(Py2 (Me) tacn)](2+) (M=Ru, Fe) complexes is due to the difference in the redox stability of the key M(V) (O) intermediate. These results contribute to a better understanding of the WO mechanism and the differences between iron and ruthenium complexes in WO reactions.
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Affiliation(s)
- Carla Casadevall
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Avinguda Països Catalans 16, 43007, Tarragona, Spain
| | - Zoel Codolà
- Institut de Química Computacional i Catàlisi (IQCC) and, Departament de Química, Universitat de Girona Campus Montilivi, 17071, Girona, Spain
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC) and, Departament de Química, Universitat de Girona Campus Montilivi, 17071, Girona, Spain
| | - Julio Lloret-Fillol
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Avinguda Països Catalans 16, 43007, Tarragona, Spain.
- Catalan Institution for Research and Advanced Studies (ICREA), Passeig Lluïs Companys, 23, 08010, Barcelona, Spain.
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Panchbhai G, Singh WM, Das B, Jane RT, Thapper A. Mononuclear Iron Complexes with Tetraazadentate Ligands as Water Oxidation Catalysts. Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201600165] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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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Puri M, Company A, Sabenya G, Costas M, Que L. Oxygen Atom Exchange between H2O and Non-Heme Oxoiron(IV) Complexes: Ligand Dependence and Mechanism. Inorg Chem 2016; 55:5818-27. [DOI: 10.1021/acs.inorgchem.6b00023] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mayank Puri
- Department of Chemistry and Center for
Metals in Biocatalysis, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Anna Company
- Grup de
Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT),
Institut de Química Computacional i Catàlisi (IQCC),
Departament de Química, Universitat de Girona, Campus de
Montilivi, E17071, Girona, Catalonia Spain
| | - Gerard Sabenya
- Grup de
Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT),
Institut de Química Computacional i Catàlisi (IQCC),
Departament de Química, Universitat de Girona, Campus de
Montilivi, E17071, Girona, Catalonia Spain
| | - Miquel Costas
- Grup de
Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT),
Institut de Química Computacional i Catàlisi (IQCC),
Departament de Química, Universitat de Girona, Campus de
Montilivi, E17071, Girona, Catalonia Spain
| | - Lawrence Que
- Department of Chemistry and Center for
Metals in Biocatalysis, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
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In vitro and in vivo identification of tetradentated polyamine complexes as highly efficient metallodrugs against Trypanosoma cruzi. Exp Parasitol 2016; 164:20-30. [DOI: 10.1016/j.exppara.2016.02.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 02/04/2016] [Accepted: 02/05/2016] [Indexed: 12/20/2022]
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Roithová J, Gray A, Andris E, Jašík J, Gerlich D. Helium Tagging Infrared Photodissociation Spectroscopy of Reactive Ions. Acc Chem Res 2016; 49:223-30. [PMID: 26821086 DOI: 10.1021/acs.accounts.5b00489] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The interrogation of reaction intermediates is key for understanding chemical reactions; however their direct observation and study remains a considerable challenge. Mass spectrometry is one of the most sensitive analytical techniques, and its use to study reaction mixtures is now an established practice. However, the information that can be obtained is limited to elemental analysis and possibly to fragmentation behavior, which is often challenging to analyze. In order to extend the available experimental information, different types of spectroscopy in the infrared and visible region have been combined with mass spectrometry. Spectroscopy of mass selected ions usually utilizes the powerful sensitivity of mass spectrometers, and the absorption of photons is not detected as such but rather translated to mass changes. One approach to accomplish such spectroscopy involves loosely binding a tag to an ion that will be removed by absorption of one photon. We have constructed an ion trapping instrument capable of reaching temperatures that are sufficiently low to enable tagging by helium atoms in situ, thus permitting infrared photodissociation spectroscopy (IRPD) to be carried out. While tagging by larger rare gas atoms, such as neon or argon is also possible, these may cause significant structural changes to small and reactive species, making the use of helium highly beneficial. We discuss the "innocence" of helium as a tag in ion spectroscopy using several case studies. It is shown that helium tagging is effectively innocent when used with benzene dications, not interfering with their structure or IRPD spectrum. We have also provided a case study where we can see that despite its minimal size there are systems where He has a huge effect. A strong influence of the He tagging was shown in the IRPD spectra of HCCl(2+) where large spectral shifts were observed. While the presented systems are rather small, they involve the formation of mixtures of isomers. We have therefore implemented two-color experiments where one laser is employed to selectively deplete a mixture by one (or more) isomer allowing helium tagging IRPD spectra of the remaining isomer(s) to be recorded via the second laser. Our experimental setup, based on a linear wire quadrupole ion trap, allows us to deplete almost 100% of all helium tagged ions in the trap. Using this special feature, we have developed attenuation experiments for determination of absolute photofragmentation cross sections. At the same time, this approach can be used to estimate the representation of isomers in a mixture. The ultimate aim is the routine use of this instrument and technique to study a wide range of reaction intermediates in catalysis. To this end, we present a study of hypervalent iron(IV)-oxo complexes ([(L)Fe(O)(NO3)](+)). We show that we can spectroscopically differentiate iron complexes with S = 1 and S = 2 according to the stretching vibrations of a nitrate counterion.
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Affiliation(s)
- Jana Roithová
- Department of Organic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030, Prague 2, 128 43, Czech Republic
| | - Andrew Gray
- Department of Organic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030, Prague 2, 128 43, Czech Republic
| | - Erik Andris
- Department of Organic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030, Prague 2, 128 43, Czech Republic
| | - Juraj Jašík
- Department of Organic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030, Prague 2, 128 43, Czech Republic
| | - Dieter Gerlich
- Department of Organic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030, Prague 2, 128 43, Czech Republic
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Andris E, Jašík J, Gómez L, Costas M, Roithová J. Spectroscopic Characterization and Reactivity of Triplet and Quintet Iron(IV) Oxo Complexes in the Gas Phase. Angew Chem Int Ed Engl 2016; 55:3637-41. [PMID: 26878833 PMCID: PMC4778411 DOI: 10.1002/anie.201511374] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Indexed: 11/23/2022]
Abstract
Closely structurally related triplet and quintet iron(IV) oxo complexes with a tetradentate aminopyridine ligand were generated in the gas phase, spectroscopically characterized, and their reactivities in hydrogen‐transfer and oxygen‐transfer reactions were compared. The spin states were unambiguously assigned based on helium tagging infrared photodissociation (IRPD) spectra of the mass‐selected iron complexes. It is shown that the stretching vibrations of the nitrate counterion can be used as a spectral marker of the central iron spin state.
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Affiliation(s)
- Erik Andris
- Department of Organic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030/8, 12843, Prague 2, Czech Republic
| | - Juraj Jašík
- Department of Organic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030/8, 12843, Prague 2, Czech Republic
| | - Laura Gómez
- Departament de Quimica and Institute of Computational Chemistry and Catalysis (IQCC), University of Girona, Campus Montilivi, Girona, 17071, Spain.,Serveis Tècnics de Recerca (STR), Universitat de Girona, Parc Científic i Tecnològic, 17003, Girona, Spain
| | - Miquel Costas
- Departament de Quimica and Institute of Computational Chemistry and Catalysis (IQCC), University of Girona, Campus Montilivi, Girona, 17071, Spain.
| | - Jana Roithová
- Department of Organic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030/8, 12843, Prague 2, Czech Republic.
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50
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Andris E, Jašík J, Gómez L, Costas M, Roithová J. Spectroscopic Characterization and Reactivity of Triplet and Quintet Iron(IV) Oxo Complexes in the Gas Phase. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201511374] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Erik Andris
- Department of Organic Chemistry; Faculty of Science; Charles University in Prague; Hlavova 2030/8 12843 Prague 2 Czech Republic
| | - Juraj Jašík
- Department of Organic Chemistry; Faculty of Science; Charles University in Prague; Hlavova 2030/8 12843 Prague 2 Czech Republic
| | - Laura Gómez
- Departament de Quimica and Institute of Computational Chemistry and Catalysis (IQCC); University of Girona; Campus Montilivi Girona 17071 Spain
- Serveis Tècnics de Recerca (STR); Universitat de Girona; Parc Científic i Tecnològic 17003 Girona Spain
| | - Miquel Costas
- Departament de Quimica and Institute of Computational Chemistry and Catalysis (IQCC); University of Girona; Campus Montilivi Girona 17071 Spain
| | - Jana Roithová
- Department of Organic Chemistry; Faculty of Science; Charles University in Prague; Hlavova 2030/8 12843 Prague 2 Czech Republic
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