1
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Katoch A, Mandal D. Impact of carboxylate ligation on the C-H activation reactivity of a non-heme Fe(IV)O complex: a computational investigation. Dalton Trans 2024. [PMID: 39222036 DOI: 10.1039/d4dt02139h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
A comprehensive DFT investigation has been presented to predict how a carboxylate-rich macrocycle would affect the reactivity of a non-heme Fe(IV)O complex towards C-H activation. The popular non-heme iron oxo complex [FeIV(O)(N4Py)]2+, (N4Py = N,N-(bis(2-pyridyl)methyl)N-bis(2-pyridylmethyl)amine) (1), has been selected here as the primary compound. It is transformed to the compound [FeIV(O)(nBu-P2DA)], where nBu-P2DA = N-(1',1'-bis(2-pyridyl)pentyl)iminodiacetate (2) after the replacement of two pyridine donors of N4Py with carboxylate groups. Two other complexes, namely 3 and 4, have been predicted sequentially substituting nitrogen with the carboxylate groups. Ethylbenzene and dihydrotoluene were chosen as substrates. In terms of C-H activation reactivity, an interesting pattern emerges: as the carboxylate group becomes more equatorially enriched, the reactivity increases, following the trend 1 < 2 < 3 < 4. This also aligns with available experimental reports related to complexes 1 and 2. Fe(IV)O complexes exhibit two-state reactivity (triplet and quintet), whereas the quintet state is more favourable due to the stabilization of the transition states through exchange interactions involving a greater number of unpaired electrons. A detailed analysis of the factors influencing reactivity has been performed, including distortion energy (which decreases for the transition state with the addition of carboxylate groups), the triplet-quintet oxidant energy gap (which consistently decreases as carboxylate group enrichment increases), steric factors, and quantum mechanical tunneling. This investigation provides a detailed explanation of the observed outcomes and predicts the higher reactivity of carboxylate-enriched Fe(IV)O complexes. After potential experimental verification, this could lead to the development of new, optimal catalysts for C-H activation.
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Affiliation(s)
- Akanksha Katoch
- Department of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala-147001, Punjab, India.
| | - Debasish Mandal
- Department of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala-147001, Punjab, India.
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2
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Janisse SE, Fernandez RL, Heffern MC. Characterizing metal-biomolecule interactions by mass spectrometry. Trends Biochem Sci 2023; 48:815-825. [PMID: 37433704 DOI: 10.1016/j.tibs.2023.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 06/13/2023] [Accepted: 06/14/2023] [Indexed: 07/13/2023]
Abstract
Metal micronutrients are essential for life and exist in a delicate balance to maintain an organism's health. The labile nature of metal-biomolecule interactions clouds the understanding of metal binders and metal-mediated conformational changes that are influential to health and disease. Mass spectrometry (MS)-based methods and technologies have been developed to better understand metal micronutrient dynamics in the intra- and extracellular environment. In this review, we describe the challenges associated with studying labile metals in human biology and highlight MS-based methods for the discovery and study of metal-biomolecule interactions.
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Affiliation(s)
- Samuel E Janisse
- Department of Chemistry, University of California, Davis, One Shields Drive, Davis, CA 95616, USA
| | - Rebeca L Fernandez
- Department of Chemistry, University of California, Davis, One Shields Drive, Davis, CA 95616, USA
| | - Marie C Heffern
- Department of Chemistry, University of California, Davis, One Shields Drive, Davis, CA 95616, USA.
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3
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Shapterhasmi T, Palani N, Velusamy M, Bhuvanesh NS, Sundaravel K, Easwaramoorthi S. Iron(III) Complexes of Pyrrolidine and Piperidine Appended Tridentate 3N Donor Ligands as Models for Catechol Dioxygenase Enzymes. Inorganica Chim Acta 2022. [DOI: 10.1016/j.ica.2022.120924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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4
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Monkcom EC, Negenman HA, Masferrer-Rius E, Lutz M, Ye S, Bill E, Klein Gebbink RJ. 2H1C Mimicry: Bioinspired Iron and Zinc Complexes Supported by N,N,O Phenolate Ligands. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202101046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Emily C. Monkcom
- Utrecht University: Universiteit Utrecht Organic Chemistry and Catalysis Universiteitsweg 99 3584CG Utrecht NETHERLANDS
| | - Hidde A. Negenman
- Utrecht University: Universiteit Utrecht Organic Chemistry and Catalysis Universiteitsweg 99 3584CG Utrecht NETHERLANDS
| | - Eduard Masferrer-Rius
- Utrecht University: Universiteit Utrecht Organic Chemistry and Catalysis Universiteitsweg 99 3584CG Utrecht NETHERLANDS
| | - Martin Lutz
- Utrecht University: Universiteit Utrecht Crystal and Structural Chemistry Universiteitsweg 99 3584CG Utrecht NETHERLANDS
| | - Shengfa Ye
- Chinese Academy of Sciences Institute of Chemistry 457 Zhongshan Road 116023 Dalian CHINA
| | - Eckhard Bill
- Max Planck Institute of Coal Research: Max-Planck-Institut fur Kohlenforschung Inorganic Spectroscopy Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr GERMANY
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5
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Kutasevich AV, Niktarov AS, Uvarova ES, Karnoukhova VA, Mityanov VS. A novel approach to bis(1,3-azol-2-yl)acetonitriles and bis(1,3-azol-2-yl)methanes via the [3 + 2]-dipolar cycloaddition of imidazole N-oxides and 2-heteroaryl-3,3-dimethylacrylonitriles. Org Biomol Chem 2021; 19:8988-8998. [PMID: 34596641 DOI: 10.1039/d1ob01441b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new synthetic approach for obtaining previously unknown bis(1,3-azol-2-yl)acetonitriles and bis(1,3-azol-2-yl)methanes has been developed. It is based on 1,3-dipolar cycloaddition between 2-unsubstituted imidazole N-oxides and 2-(1,3-azol-2-yl)-3,3-dimethylacrylonitriles, which are easily available through the condensation of (1,3-azol-2-yl)acetonitriles with acetone. The method allows for the construction of various unsymmetric derivatives based on imidazole, oxazole, thiazole, and 1,3,4-thiadiazole cyclic molecules. Its potential has been demonstrated via the synthesis of 24 diverse derivatives with yields of 29-92%. Bis(1,3-azol-2-yl)acetonitriles can be converted to the corresponding bis(1,3-azol-2-yl)methanes via simple acid hydrolysis followed by subsequent spontaneous decarboxylation at nearly quantitative yields.
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Affiliation(s)
- Anton V Kutasevich
- Department of Fine Organic Synthesis and Chemistry of Dyes, Mendeleev University of Chemical Technology, Miusskaya Sq., 9, Moscow 125047, Russian Federation.
| | - Anton S Niktarov
- Department of Fine Organic Synthesis and Chemistry of Dyes, Mendeleev University of Chemical Technology, Miusskaya Sq., 9, Moscow 125047, Russian Federation.
| | - Ekaterina S Uvarova
- Department of Fine Organic Synthesis and Chemistry of Dyes, Mendeleev University of Chemical Technology, Miusskaya Sq., 9, Moscow 125047, Russian Federation.
| | - Valentina A Karnoukhova
- A.N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences, Vavilova St. 28, Moscow, 119991, Russian Federation
| | - Vitaly S Mityanov
- Department of Fine Organic Synthesis and Chemistry of Dyes, Mendeleev University of Chemical Technology, Miusskaya Sq., 9, Moscow 125047, Russian Federation.
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6
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Bete SC, Otte M. Heteroleptische Koordination durch einen
endo
‐funktionalisierten Käfig. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202106341] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Sarah C. Bete
- Institut für Anorganische Chemie Universität Göttingen Tammannstraße 4 37077 Göttingen Deutschland
| | - Matthias Otte
- Institut für Anorganische Chemie Universität Göttingen Tammannstraße 4 37077 Göttingen Deutschland
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7
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Bete SC, Otte M. Heteroleptic Ligation by an endo-Functionalized Cage. Angew Chem Int Ed Engl 2021; 60:18582-18586. [PMID: 34124838 PMCID: PMC8456844 DOI: 10.1002/anie.202106341] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Indexed: 12/20/2022]
Abstract
A conceptual approach for the synthesis of quasi-heteroleptic complexes with properly endo-functionalized cages as ligands is presented. The cage ligand reported here is of a covalent organic nature, it has been synthesized via a dynamic combinatorial chemistry approach, making use of a masked amine. Inspired by enzymatic active sites, the described system bears one carboxylate and two imidazole moieties as independent ligating units through which it is able to coordinate to transition metals. Analysis of the iron(II) complex in solution and the solid state validates the structure and shows that no undesired but commonly observed dimerization process takes place. The solid-state structure shows a five-coordinate metal center with the carboxylate bidentately bound to iron, which makes Fe@2 an unprecedentedly detailed structural model complex for this kind of non-heme iron oxygenases. As, as confirmed by the crystal structure, sufficient space for other organic ligands is available, the biologically relevant ligand α-ketoglutarate is implemented. We observe biomimetic reaction behavior towards dioxygen that opens studies investigating Fe@2 as a functional model complex.
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Affiliation(s)
- Sarah C Bete
- Institut für Anorganische Chemie, University of Goettingen, Tammannstraße 4, 37077, Göttingen, Germany
| | - Matthias Otte
- Institut für Anorganische Chemie, University of Goettingen, Tammannstraße 4, 37077, Göttingen, Germany
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8
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Monkcom EC, de Bruin D, de Vries AJ, Lutz M, Ye S, Klein Gebbink RJM. Structurally Modelling the 2-His-1-Carboxylate Facial Triad with a Bulky N,N,O Phenolate Ligand. Chemistry 2021; 27:5191-5204. [PMID: 33326655 PMCID: PMC8048785 DOI: 10.1002/chem.202004633] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Indexed: 11/25/2022]
Abstract
We present the synthesis and coordination chemistry of a bulky, tripodal N,N,O ligand, ImPh2NNOtBu (L), designed to model the 2‐His‐1‐carboxylate facial triad (2H1C) by means of two imidazole groups and an anionic 2,4‐di‐tert‐butyl‐subtituted phenolate. Reacting K‐L with MCl2 (M = Fe, Zn) affords the isostructural, tetrahedral non‐heme complexes [Fe(L)(Cl)] (1) and [Zn(L)(Cl)] (2) in high yield. The tridentate N,N,O ligand coordination observed in their X‐ray crystal structures remains intact and well‐defined in MeCN and CH2Cl2 solution. Reacting 2 with NaSPh affords a tetrahedral zinc thiolate complex, [Zn(L)(SPh)] (4), that is relevant to isopenicillin N synthase (IPNS) biomimicry. Cyclic voltammetry studies demonstrate the ligand's redox non‐innocence, where phenolate oxidation is the first electrochemical response observed in K‐L, 2 and 4. However, the first electrochemical oxidation in 1 is iron‐centred, the assignment of which is supported by DFT calculations. Overall, ImPh2NNOtBu provides access to well‐defined mononuclear, monoligated, N,N,O‐bound metal complexes, enabling more accurate structural modelling of the 2H1C to be achieved.
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Affiliation(s)
- Emily C Monkcom
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584, CG, Utrecht, The Netherlands
| | - Daniël de Bruin
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584, CG, Utrecht, The Netherlands
| | - Annemiek J de Vries
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584, CG, Utrecht, The Netherlands
| | - Martin Lutz
- Crystal and Structural Chemistry, Bijvoet Centre for Biomolecular Research, Utrecht University, Padualaan 8, 3584, CH, Utrecht, The Netherlands
| | - Shengfa Ye
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian, 116023, P. R. China.,Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany
| | - Robertus J M Klein Gebbink
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584, CG, Utrecht, The Netherlands
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9
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Gunasekera PS, Abhyankar PC, MacMillan SN, Lacy DC. A Facially Coordinating Tris‐Benzimidazole Ligand for Nonheme Iron Enzyme Models. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202000984] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Parami S. Gunasekera
- Department of Chemistry University at Buffalo State University of New York Buffalo New York 14260 United States
| | - Preshit C. Abhyankar
- Department of Chemistry University at Buffalo State University of New York Buffalo New York 14260 United States
| | - Samantha N. MacMillan
- Department of Chemistry and Chemical Biology Cornell University Ithaca New York 14853 United States
| | - David C. Lacy
- Department of Chemistry University at Buffalo State University of New York Buffalo New York 14260 United States
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10
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Gunasekera PS, MacMillan SN, Lacy DC. Synthesis and coordination of a tert-butyl functionalized facially coordinating 2-histidine-1-carboxylate model ligand. J COORD CHEM 2021. [DOI: 10.1080/00958972.2021.1878353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Parami S. Gunasekera
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, NY, USA
| | | | - David C. Lacy
- Department of Chemistry, University at Buffalo, State University of New York, Buffalo, NY, USA
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11
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Kumar Pal C, Mahato S, Joshi M, Paul S, Roy Choudhury A, Biswas B. Transesterification activity by a zinc(II)-Schiff base complex with theoretical interpretation. Inorganica Chim Acta 2020. [DOI: 10.1016/j.ica.2020.119541] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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12
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Miller KR, Paretsky JD, Follmer AH, Heinisch T, Mittra K, Gul S, Kim IS, Fuller FD, Batyuk A, Sutherlin KD, Brewster AS, Bhowmick A, Sauter NK, Kern J, Yano J, Green MT, Ward TR, Borovik AS. Artificial Iron Proteins: Modeling the Active Sites in Non-Heme Dioxygenases. Inorg Chem 2020; 59:6000-6009. [PMID: 32309932 PMCID: PMC7219546 DOI: 10.1021/acs.inorgchem.9b03791] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An important class of non-heme dioxygenases contains a conserved Fe binding site that consists of a 2-His-1-carboxylate facial triad. Results from structural biology show that, in the resting state, these proteins are six-coordinate with aqua ligands occupying the remaining three coordination sites. We have utilized biotin-streptavidin (Sav) technology to design new artificial Fe proteins (ArMs) that have many of the same structural features found within active sites of these non-heme dioxygenases. An Sav variant was isolated that contains the S112E mutation, which installed a carboxylate side chain in the appropriate position to bind to a synthetic FeII complex confined within Sav. Structural studies using X-ray diffraction (XRD) methods revealed a facial triad binding site that is composed of two N donors from the biotinylated ligand and the monodentate coordination of the carboxylate from S112E. Two aqua ligands complete the primary coordination sphere of the FeII center with both involved in hydrogen bond networks within Sav. The corresponding FeIII protein was also prepared and structurally characterized to show a six-coordinate complex with two exogenous acetato ligands. The FeIII protein was further shown to bind an exogenous azido ligand through replacement of one acetato ligand. Spectroscopic studies of the ArMs in solution support the results found by XRD.
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Affiliation(s)
- Kelsey R. Miller
- Department of Chemistry, 1102 Natural Science II, University of California, Irvine, CA 9269
| | - Jonathan D. Paretsky
- Department of Chemistry, 1102 Natural Science II, University of California, Irvine, CA 9269
| | - Alec H. Follmer
- Department of Chemistry, 1102 Natural Science II, University of California, Irvine, CA 9269
| | - Tillmann Heinisch
- Department of Chemistry, University of Basel, PO Box 3350, Mattenstrasse 24a, BPR 1096, CH-4002 Basel, Switzerland
| | - Kaustuv Mittra
- Department of Molecular Biosciences and Biochemistry, University of California, Irvine, CA 92697
| | - Sheraz Gul
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - In-Sik Kim
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Franklin D. Fuller
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025 USA
| | - Alexander Batyuk
- Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025 USA
| | - Kyle D. Sutherlin
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Aaron S. Brewster
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Asmit Bhowmick
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Nicholas K. Sauter
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Jan Kern
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Junko Yano
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Michael T. Green
- Department of Chemistry, 1102 Natural Science II, University of California, Irvine, CA 9269
- Department of Molecular Biosciences and Biochemistry, University of California, Irvine, CA 92697
| | - Thomas R. Ward
- Department of Chemistry, University of Basel, PO Box 3350, Mattenstrasse 24a, BPR 1096, CH-4002 Basel, Switzerland
| | - A. S. Borovik
- Department of Chemistry, 1102 Natural Science II, University of California, Irvine, CA 9269
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13
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Pal CK, Mahato S, Yadav HR, Shit M, Choudhury AR, Biswas B. Bio-mimetic of catecholase and phosphatase activity by a tetra-iron(III) cluster. Polyhedron 2019. [DOI: 10.1016/j.poly.2019.114156] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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14
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Li C, Chen C, Wu X, Tsang CW, Mou J, Yan J, Liu Y, Lin CSK. Recent advancement in lignin biorefinery: With special focus on enzymatic degradation and valorization. BIORESOURCE TECHNOLOGY 2019; 291:121898. [PMID: 31395402 DOI: 10.1016/j.biortech.2019.121898] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/22/2019] [Accepted: 07/23/2019] [Indexed: 05/07/2023]
Abstract
With the intensive development of lignocellulosic biorefineries to produce fuels and chemicals from biomass-derived carbohydrates, lignin was generated at a large quantity every year. Therefore, lignin has received increasing attention as an abundant aromatics resource in terms of research and development efforts for value-added chemicals production. In this review, studies about lignin degradation especially the crucial enzymes involved and the reaction mechanism were substantially discussed, which provided the molecular basis of lignin biodegradation. Then, the latest improvements in lignin valorization by biological methods were summarized and case studies about value-added compounds from lignin were introduced. Afterwards, challenges, opportunities and prospects regarding biorefinery of lignin were presented.
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Affiliation(s)
- Chong Li
- Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, Guangdong 518120, People's Republic of China
| | - Chao Chen
- BioZone, Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON M5S 3E5, Canada
| | - Xiaofen Wu
- Hunan Institute of Nuclear Agricultural Science and Space Breeding, Hunan Academy of Agricultural Sciences, Changsha, Hunan 410125, People's Republic of China
| | - Chi-Wing Tsang
- Faculty of Science and Technology, Technological and Higher Education Institute of Hong Kong, Hong Kong, China
| | - Jinhua Mou
- School of Energy and Environment, City University of Hong Kong, Hong Kong
| | - Jianbin Yan
- Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, Guangdong 518120, People's Republic of China
| | - Yun Liu
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China
| | - Carol Sze Ki Lin
- School of Energy and Environment, City University of Hong Kong, Hong Kong.
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15
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Chetty N, Ramkumar V, Murthy NN. Bis- and mono-tridentate chelated iron complexes with a new facially capping unsymmetrical nitrogen ligand: X-ray structural and spectroscopic studies. Polyhedron 2019. [DOI: 10.1016/j.poly.2018.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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16
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Corcoran CJ, Tang CC, Lykourinou V, Terentis AC, Angerhofer A, Ming LJ. To be structurally well-defined or not to be, that is not the question for iron(III)–poly(4-Vinylpyridine-co-acrylamide) to exhibit catechol dioxygenase activity! CATAL COMMUN 2018. [DOI: 10.1016/j.catcom.2017.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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17
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Ségaud N, Drienovská I, Chen J, Browne WR, Roelfes G. Artificial Metalloproteins for Binding and Stabilization of a Semiquinone Radical. Inorg Chem 2018; 56:13293-13299. [PMID: 29027794 PMCID: PMC5676253 DOI: 10.1021/acs.inorgchem.7b02073] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
![]()
The interaction of a number of first-row
transition-metal ions with a 2,2′-bipyridyl alanine (bpyA)
unit incorporated into the lactococcal multidrug resistance regulator
(LmrR) scaffold is reported. The composition of the active site is
shown to influence binding affinities. In the case of Fe(II), we demonstrate
the need of additional ligating residues, in particular those containing
carboxylate groups, in the vicinity of the binding site. Moreover,
stabilization of di-tert-butylsemiquinone radical
(DTB-SQ) in water was achieved by binding to the designed
metalloproteins, which resulted in the radical being shielded from
the aqueous environment. This allowed the first characterization of
the radical semiquinone in water by resonance Raman spectroscopy. A coordination study of first-row transition-metal ions to bipyridine
alanine (bpyA) incorporated into the lactococcal multidrug resistance
regulator (LmrR) scaffold is reported. The designed metalloproteins
were shown to bind and stabilize the di-tert-butylsemiquinone
radical (DTB-SQ) in water, allowing for the first resonance
Raman characterization of this radical species in water.
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Affiliation(s)
- Nathalie Ségaud
- Stratingh Institute for Chemistry, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Ivana Drienovská
- Stratingh Institute for Chemistry, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Juan Chen
- Stratingh Institute for Chemistry, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Wesley R Browne
- Stratingh Institute for Chemistry, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Gerard Roelfes
- Stratingh Institute for Chemistry, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
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18
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Crystallization, Structure Determination and Reticular Twinning in Iron(III) Salicylate: Fe[(HSal)(Sal)(H2O)2]. CRYSTALS 2017. [DOI: 10.3390/cryst7120377] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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19
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Rigid scaffolds for the design of molecular catalysts and biomimetic active sites: A case study of anthracene-based ligands for modeling mono-iron hydrogenase (Hmd). Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.09.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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20
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Oxygen activation by mononuclear Mn, Co, and Ni centers in biology and synthetic complexes. J Biol Inorg Chem 2016; 22:407-424. [PMID: 27853875 DOI: 10.1007/s00775-016-1402-7] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 10/21/2016] [Indexed: 10/20/2022]
Abstract
The active sites of metalloenzymes that catalyze O2-dependent reactions generally contain iron or copper ions. However, several enzymes are capable of activating O2 at manganese or nickel centers instead, and a handful of dioxygenases exhibit activity when substituted with cobalt. This minireview summarizes the catalytic properties of oxygenases and oxidases with mononuclear Mn, Co, or Ni active sites, including oxalate-degrading oxidases, catechol dioxygenases, and quercetin dioxygenase. In addition, recent developments in the O2 reactivity of synthetic Mn, Co, or Ni complexes are described, with an emphasis on the nature of reactive intermediates featuring superoxo-, peroxo-, or oxo-ligands. Collectively, the biochemical and synthetic studies discussed herein reveal the possibilities and limitations of O2 activation at these three "overlooked" metals.
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21
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Sahu S, Goldberg DP. Activation of Dioxygen by Iron and Manganese Complexes: A Heme and Nonheme Perspective. J Am Chem Soc 2016; 138:11410-28. [PMID: 27576170 DOI: 10.1021/jacs.6b05251] [Citation(s) in RCA: 229] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The rational design of well-defined, first-row transition metal complexes that can activate dioxygen has been a challenging goal for the synthetic inorganic chemist. The activation of O2 is important in part because of its central role in the functioning of metalloenzymes, which utilize O2 to perform a number of challenging reactions including the highly selective oxidation of various substrates. There is also great interest in utilizing O2, an abundant and environmentally benign oxidant, in synthetic catalytic oxidation systems. This Perspective brings together recent examples of biomimetic Fe and Mn complexes that can activate O2 in heme or nonheme-type ligand environments. The use of oxidants such as hypervalent iodine (e.g., ArIO), peracids (e.g., m-CPBA), peroxides (e.g., H2O2) or even superoxide is a popular choice for accessing well-characterized metal-superoxo, metal-peroxo, or metal-oxo species, but the instances of biomimetic Fe/Mn complexes that react with dioxygen to yield such observable metal-oxygen species are surprisingly few. This Perspective focuses on mononuclear Fe and Mn complexes that exhibit reactivity with O2 and lead to spectroscopically observable metal-oxygen species, and/or oxidize biologically relevant substrates. Analysis of these examples reveals that solvent, spin state, redox potential, external co-reductants, and ligand architecture can all play important roles in the O2 activation process.
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Affiliation(s)
- Sumit Sahu
- Department of Chemistry, The Johns Hopkins University , Baltimore, Maryland 21218, United States
| | - David P Goldberg
- Department of Chemistry, The Johns Hopkins University , Baltimore, Maryland 21218, United States
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22
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Dey D, De A, Yadav HR, Guin PS, Choudhury AR, Kole N, Biswas B. An Oxido-Bridged Diiron(II) Complex as Functional Model of Catechol Dioxygenase. ChemistrySelect 2016. [DOI: 10.1002/slct.201600575] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Dhananjay Dey
- Department of Chemistry; Raghunathpur College; Purulia 723 133,West Bengal India
| | - Abhranil De
- Department of Chemistry; Raghunathpur College; Purulia 723 133,West Bengal India
| | - Hare Ram Yadav
- Department of Chemical Sciences; Indian Institute of Science Education and Research Mohali; S.A.S. Nagar, Manauli PO Mohali 140 306 India
| | | | - Angshuman Roy Choudhury
- Department of Chemical Sciences; Indian Institute of Science Education and Research Mohali; S.A.S. Nagar, Manauli PO Mohali 140 306 India
| | - Niranjan Kole
- Department of Chemistry; Raghunathpur College; Purulia 723 133,West Bengal India
| | - Bhaskar Biswas
- Department of Chemistry; Raghunathpur College; Purulia 723 133,West Bengal India
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23
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Lakshman TR, Chatterjee S, Chakraborty B, Paine TK. Substrate-dependent aromatic ring fission of catechol and 2-aminophenol with O2 catalyzed by a nonheme iron complex of a tripodal N4 ligand. Dalton Trans 2016; 45:8835-44. [PMID: 27148606 DOI: 10.1039/c5dt04541j] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The catalytic reactivity of an iron(ii) complex [(TPA)Fe(II)(CH3CN)2](2+) (1) (TPA = tris(2-pyridylmethyl)amine) towards oxygenative aromatic C-C bond cleavage of catechol and 2-aminophenol is presented. Complex 1 exhibits catalytic and regioselective C-C bond cleavage of 3,5-di-tert-butylcatechol (H2DBC) to form intradiol products, whereas it catalyzes extradiol-type C-C bond cleavage of 2-amino-4,6-di-tert-butylphenol (H2AP). The catalytic reactions are found to be pH-dependent and the complex exhibits maximum turnovers at pH 5 in acetonitrile-phthalate buffer. An iron(iii)-catecholate complex [(TPA)Fe(III)(DBC)](+) (2) is formed in the ring cleavage of catechol. In the extradiol-type cleavage of H2AP, an iron(iii)-2-iminobenzosemiquinonate complex [(TPA)Fe(III)(ISQ)](2+) (3) (ISQ = 4,6-di-tert-butyl-2-iminobenzosemiquinonate radical anion) is observed in the reaction pathway. This work shows the importance of the nature of 'redox non-innocent' substrates in governing the mode of ring fission reactivity.
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Affiliation(s)
- Triloke Ranjan Lakshman
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A&2B Raja S. C. Mullick Road, Jadavpur, Kolkata-700032, India.
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24
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Folkertsma E, de Waard EF, Korpershoek G, van Schaik AJ, Solozabal Mirón N, Borrmann M, Nijsse S, Moelands MAH, Lutz M, Otte M, Moret M, Klein Gebbink RJM. Mimicry of the 2‐His‐1‐Carboxylate Facial Triad Using Bulky N,N,O‐Ligands: Non‐Heme Iron Complexes Featuring a Single Facial Ligand and Easily Exchangeable Co‐Ligands. Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201501406] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Emma Folkertsma
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands, http://www.uu.nl/en/research/organic‐chemistry‐catalysis
| | - Esther F. de Waard
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands, http://www.uu.nl/en/research/organic‐chemistry‐catalysis
| | - Gerda Korpershoek
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands, http://www.uu.nl/en/research/organic‐chemistry‐catalysis
| | - Arnoldus J. van Schaik
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands, http://www.uu.nl/en/research/organic‐chemistry‐catalysis
| | - Naiara Solozabal Mirón
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands, http://www.uu.nl/en/research/organic‐chemistry‐catalysis
| | - Mandy Borrmann
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands, http://www.uu.nl/en/research/organic‐chemistry‐catalysis
| | - Sjoerd Nijsse
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands, http://www.uu.nl/en/research/organic‐chemistry‐catalysis
| | - Marcel A. H. Moelands
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands, http://www.uu.nl/en/research/organic‐chemistry‐catalysis
| | - Martin Lutz
- Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Matthias Otte
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands, http://www.uu.nl/en/research/organic‐chemistry‐catalysis
| | - Marc‐Etienne Moret
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands, http://www.uu.nl/en/research/organic‐chemistry‐catalysis
| | - Robertus J. M. Klein Gebbink
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands, http://www.uu.nl/en/research/organic‐chemistry‐catalysis
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25
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Baum AE, Lindeman SV, Fiedler AT. Mononuclear Iron‐(hydro/semi)quinonate Complexes Featuring Neutral and Charged Scorpionates: Synthetic Models of Intermediates in the Hydroquinone Dioxygenase Mechanism. Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201501380] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Amanda E. Baum
- Department of ChemistryMarquette UniversityP. O. Box 1881, 535 N. 14th St.53233MilwaukeeWIUSA
| | - Sergey V. Lindeman
- Department of ChemistryMarquette UniversityP. O. Box 1881, 535 N. 14th St.53233MilwaukeeWIUSA
| | - Adam T. Fiedler
- Department of ChemistryMarquette UniversityP. O. Box 1881, 535 N. 14th St.53233MilwaukeeWIUSA
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26
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Moelands MAH, Schamhart DJ, Folkertsma E, Lutz M, Spek AL, Klein Gebbink RJM. Facial triad modelling using ferrous pyridinyl prolinate complexes: synthesis and catalytic applications. Dalton Trans 2015; 43:6769-85. [PMID: 24647553 DOI: 10.1039/c3dt53266f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of new chiral pyridinyl prolinate (RPyProR) ligands and their corresponding Fe(II) triflate and chloride complexes are reported. The ligands possess an NN'O coordination motif, as found in the active site of non-heme iron enzymes with the so-called 2-His-1-carboxylate facial triad. The coordination behaviour of these ligands towards iron turned out to be dependent on the counter ion (chloride or triflate), the crystallization conditions (coordinating or non-coordinating solvents) and the presence of substituents on the ligand. In combination with Fe(II)(OTf)2, coordinatively saturated complexes of the type [Fe(L)2](OTf)2 are formed, in which the ligands adopt a meridional coordination mode. The use of FeCl2 in a non-coordinating solvent leads to 5-coordinated complexes [Fe(L)(Cl)2] with a meridional N,N',O ligand. Crystallization of these complexes from a coordinating solvent leads to 6-coordinated [Fe(L)(solv)(Cl)2] complexes (solv = methanol or acetonitrile), in which the N,N',O ligand is coordinated in a facial manner. For RPyProR ligands bearing a 6-Me substituent on the pyridine ring, solvent coordination and, accordingly, ligand rearrangement are prevented by steric constraints. The complexes were tested as oxidation catalysts in the epoxidation of alkene substrates in acetonitrile with hydrogen peroxide as the oxidant under oxidant limiting conditions. The complexes were shown to be especially active in the epoxidation of styrene type substrates (styrene and trans-beta-methylstyrene). In the best case, complex [Fe(6-Me-PyProNH2)Cl2] (15) allowed for 65% productive consumption of hydrogen peroxide toward epoxide and benzaldehyde products.
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Affiliation(s)
- Marcel A H Moelands
- Organic Chemistry & Catalysis, Department of Chemistry, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands.
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27
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Faponle AS, Quesne MG, Sastri CV, Banse F, de Visser SP. Differences and comparisons of the properties and reactivities of iron(III)-hydroperoxo complexes with saturated coordination sphere. Chemistry 2015; 21:1221-36. [PMID: 25399782 PMCID: PMC4316188 DOI: 10.1002/chem.201404918] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Indexed: 11/06/2022]
Abstract
Heme and nonheme monoxygenases and dioxygenases catalyze important oxygen atom transfer reactions to substrates in the body. It is now well established that the cytochrome P450 enzymes react through the formation of a high-valent iron(IV)-oxo heme cation radical. Its precursor in the catalytic cycle, the iron(III)-hydroperoxo complex, was tested for catalytic activity and found to be a sluggish oxidant of hydroxylation, epoxidation and sulfoxidation reactions. In a recent twist of events, evidence has emerged of several nonheme iron(III)-hydroperoxo complexes that appear to react with substrates via oxygen atom transfer processes. Although it was not clear from these studies whether the iron(III)-hydroperoxo reacted directly with substrates or that an initial O-O bond cleavage preceded the reaction. Clearly, the catalytic activity of heme and nonheme iron(III)-hydroperoxo complexes is substantially different, but the origins of this are still poorly understood and warrant a detailed analysis. In this work, an extensive computational analysis of aromatic hydroxylation by biomimetic nonheme and heme iron systems is presented, starting from an iron(III)-hydroperoxo complex with pentadentate ligand system (L5(2)). Direct C-O bond formation by an iron(III)-hydroperoxo complex is investigated, as well as the initial heterolytic and homolytic bond cleavage of the hydroperoxo group. The calculations show that [(L5(2))Fe(III)(OOH)](2+) should be able to initiate an aromatic hydroxylation process, although a low-energy homolytic cleavage pathway is only slightly higher in energy. A detailed valence bond and thermochemical analysis rationalizes the differences in chemical reactivity of heme and nonheme iron(III)-hydroperoxo and show that the main reason for this particular nonheme complex to be reactive comes from the fact that they homolytically split the O-O bond, whereas a heterolytic O-O bond breaking in heme iron(III)-hydroperoxo is found.
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Affiliation(s)
- Abayomi S Faponle
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, The University of Manchester131 Princess Street, Manchester M1 7DN (UK) E-mail:
| | - Matthew G Quesne
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, The University of Manchester131 Princess Street, Manchester M1 7DN (UK) E-mail:
| | - Chivukula V Sastri
- Department of Chemistry, Indian Institute of Technology Guwahati781039, Assam (India)
| | - Frédéric Banse
- Institut de Chimie Moleculaire et des Materiaux d'Orsay, Laboratoire de Chimie Inorganique, Université Paris-Sud11 91405 Orsay Cedex (France) E-mail:
| | - Sam P de Visser
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, The University of Manchester131 Princess Street, Manchester M1 7DN (UK) E-mail:
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28
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Geng L, Zhang M, Zhang W, Jia M, Yan W, Liu G. Rational design of carbon support to prepare ultrafine iron oxide catalysts for air oxidation of alcohols. Catal Sci Technol 2015. [DOI: 10.1039/c5cy00022j] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The efficient carbon supports change not only the physical but also the chemical properties of iron oxide and create new active sites for the enhancement of catalytic activity in the oxidation of alcohols with air as an oxygen source.
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Affiliation(s)
- Longlong Geng
- Key Laboratory of Surface and Interface Chemistry of Jilin Province, College of Chemistry
- Jilin University
- Changchun
- PR China
| | - Min Zhang
- Key Laboratory of Surface and Interface Chemistry of Jilin Province, College of Chemistry
- Jilin University
- Changchun
- PR China
| | - Wenxiang Zhang
- Key Laboratory of Surface and Interface Chemistry of Jilin Province, College of Chemistry
- Jilin University
- Changchun
- PR China
| | - Mingjun Jia
- Key Laboratory of Surface and Interface Chemistry of Jilin Province, College of Chemistry
- Jilin University
- Changchun
- PR China
| | - Wenfu Yan
- State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry
- Jilin University
- Changchun
- PR China
| | - Gang Liu
- Key Laboratory of Surface and Interface Chemistry of Jilin Province, College of Chemistry
- Jilin University
- Changchun
- PR China
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29
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Design and Antimicrobial Evaluation of 1-Methylimidazole Derivatives as New Antifungal and Antibacterial Agents. Pharm Chem J 2014. [DOI: 10.1007/s11094-014-1140-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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30
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Balamurugan M, Vadivelu P, Palaniandavar M. Iron(iii) complexes of tripodal tetradentate 4N ligands as functional models for catechol dioxygenases: the electronic vs. steric effect on extradiol cleavage. Dalton Trans 2014; 43:14653-68. [DOI: 10.1039/c3dt52145a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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31
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Bittner MM, Lindeman SV, Popescu CV, Fiedler AT. Dioxygen reactivity of biomimetic Fe(II) complexes with noninnocent catecholate, o-aminophenolate, and o-phenylenediamine ligands. Inorg Chem 2014; 53:4047-61. [PMID: 24697567 PMCID: PMC3998776 DOI: 10.1021/ic403126p] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Indexed: 11/28/2022]
Abstract
This study describes the O2 reactivity of a series of high-spin mononuclear Fe(II) complexes each containing the facially coordinating tris(4,5-diphenyl-1-methylimidazol-2-yl)phosphine ((Ph2)TIP) ligand and one of the following bidentate, redox-active ligands: 4-tert-butylcatecholate ((tBu)CatH(-)), 4,6-di-tert-butyl-2-aminophenolate ((tBu2)APH(-)), or 4-tert-butyl-1,2-phenylenediamine ((tBu)PDA). The preparation and X-ray structural characterization of [Fe(2+)((Ph2)TIP)((tBu)CatH)]OTf, [3]OTf and [Fe(2+)((Ph2)TIP)((tBu)PDA)](OTf)2, [4](OTf)2 are described here, whereas [Fe(2+)((Ph2)TIP)((tBu2)APH)]OTf, [2]OTf was reported in our previous paper [Bittner et al., Chem.-Eur. J. 2013, 19, 9686-9698]. These complexes mimic the substrate-bound active sites of nonheme iron dioxygenases, which catalyze the oxidative ring-cleavage of aromatic substrates like catechols and aminophenols. Each complex is oxidized in the presence of O2, and the geometric and electronic structures of the resulting complexes were examined with spectroscopic (absorption, EPR, Mössbauer, resonance Raman) and density functional theory (DFT) methods. Complex [3]OTf reacts rapidly with O2 to yield the ferric-catecholate species [Fe(3+)((Ph2)TIP)((tBu)Cat)](+) (3(ox)), which undergoes further oxidation to generate an extradiol cleavage product. In contrast, complex [4](2+) experiences a two-electron (2e(-)), ligand-based oxidation to give [Fe(2+)((Ph2)TIP)((tBu)DIBQ)](2+) (4(ox)), where DIBQ is o-diiminobenzoquinone. The reaction of [2](+) with O2 is also a 2e(-) process, yet in this case both the Fe center and (tBu2)AP ligand are oxidized; the resulting complex (2(ox)) is best described as [Fe(3+)((Ph2)TIP)((tBu2)ISQ)](+), where ISQ is o-iminobenzosemiquinone. Thus, the oxidized complexes display a remarkable continuum of electronic structures ranging from [Fe(3+)(L(2-))](+) (3(ox)) to [Fe(3+)(L(•-))](2+) (2(ox)) to [Fe(2+)(L(0))](2+) (4(ox)). Notably, the O2 reaction rates vary by a factor of 10(5) across the series, following the order [3](+) > [2](+) > [4](2+), even though the complexes have similar structures and Fe(3+/2+) redox potentials. To account for the kinetic data, we examined the relative abilities of the title complexes to bind O2 and participate in H-atom transfer reactions. We conclude that the trend in O2 reactivity can be rationalized by accounting for the role of proton transfer(s) in the overall reaction.
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Affiliation(s)
- Michael M. Bittner
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States
| | - Sergey V. Lindeman
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States
| | - Codrina V. Popescu
- Department of Chemistry, Ursinus College, Collegeville, Pennsylvania 19426, United States
| | - Adam T. Fiedler
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States
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Sankaralingam M, Saravanan N, Anitha N, Suresh E, Palaniandavar M. Biomimetic iron(iii) complexes of facially and meridionally coordinating tridentate 3N ligands: tuning of regioselective extradiol dioxygenase activity in organized assemblies. Dalton Trans 2014; 43:6828-41. [DOI: 10.1039/c3dt52350k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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33
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Models for enzyme–substrate adduct of non-heme iron-containing enzymes, synthesis and characterization. Inorganica Chim Acta 2013. [DOI: 10.1016/j.ica.2013.06.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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34
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Moelands MAH, Nijsse S, Folkertsma E, de Bruin B, Lutz M, Spek AL, Klein Gebbink RJM. Bioinspired Nonheme Iron Complexes Derived from an Extended Series of N,N,O-Ligated BAIP Ligands. Inorg Chem 2013; 52:7394-410. [DOI: 10.1021/ic400096e] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Marcel A. H. Moelands
- Organic Chemistry and Catalysis,
Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht,
The Netherlands
| | - Sjoerd Nijsse
- Organic Chemistry and Catalysis,
Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht,
The Netherlands
| | - Emma Folkertsma
- Organic Chemistry and Catalysis,
Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht,
The Netherlands
| | - Bas de Bruin
- Van’t
Hoff Institute
for Molecular Sciences (HIMS), University of Amsterdam, P.O. Box 94720, 1090 GE Amsterdam, The Netherlands
| | - Martin Lutz
- Van’t
Hoff Institute
for Molecular Sciences (HIMS), University of Amsterdam, P.O. Box 94720, 1090 GE Amsterdam, The Netherlands
- Bijvoet Center for Biomolecular
Research, Crystal and Structural Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The
Netherlands
| | - Anthony L. Spek
- Van’t
Hoff Institute
for Molecular Sciences (HIMS), University of Amsterdam, P.O. Box 94720, 1090 GE Amsterdam, The Netherlands
- Bijvoet Center for Biomolecular
Research, Crystal and Structural Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The
Netherlands
| | - Robertus J. M. Klein Gebbink
- Organic Chemistry and Catalysis,
Debye Institute for Nanomaterials Science, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht,
The Netherlands
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35
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Heidari S, Safaei E, Wojtczak A, Cotič P, Kozakiewicz A. Iron(III) complexes of pyridine-based tetradentate aminophenol ligands as structural model complexes for the catechol-bound intermediate of catechol dioxygenases. Polyhedron 2013. [DOI: 10.1016/j.poly.2013.02.067] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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36
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Das O, Chatterjee S, Paine TK. Functional models of α-keto acid dependent nonheme iron oxygenases: synthesis and reactivity of biomimetic iron(II) benzoylformate complexes supported by a 2,9-dimethyl-1,10-phenanthroline ligand. J Biol Inorg Chem 2013; 18:401-10. [PMID: 23417539 DOI: 10.1007/s00775-013-0984-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 01/31/2013] [Indexed: 01/12/2023]
Abstract
Two biomimetic iron(II) benzoylformate complexes, [LFe(II)(BF)(2)] (2) and [LFe(II)(NO(3))(BF)] (3) (L is 2,9-dimethyl-1,10-phenanthroline and BF is monoanionic benzoylformate), have been synthesized from an iron(II)-dichloro complex [LFe(II)Cl(2)] (1). All the iron(II) complexes have been structurally and spectroscopically characterized. The iron(II) center in 2 is coordinated by a bidentate NN ligand (2,9-dimethyl-1,10-phenanthroline) and two monoanionic benzoylformates to form a distorted octahedral coordination geometry. One of the benzoylformates binds to the iron in 2 via both carboxylate oxygens but the other one binds in a chelating bidentate fashion via one carboxylate oxygen and the keto oxygen. On the other hand, the iron(II) center in 3 is ligated by one NN ligand, one bidentate nitrate, and one monoanionic chelating benzoylformate. Both iron(II) benzoylformate complexes exhibit the facial NNO donor environment in their solid-state structures. Complexes 2 and 3 are stable in noncoordinating solvents under an inert atmosphere, but react with dioxygen under ambient conditions to undergo oxidative decarboxylation of benzoylformate to benzoate in high yields. Evidence for the formation of an iron(IV)-oxo intermediate upon oxidative decarboxylation of benzoylformate was obtained by interception and labeling experiments. The iron(II) benzoylformate complexes represent the functional models of α-keto acid dependent oxygenases.
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Affiliation(s)
- Oindrila Das
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Jadavpur, 700032, Kolkata, India
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37
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Chatterjee S, Sheet D, Paine TK. Catalytic and regiospecific extradiol cleavage of catechol by a biomimetic iron complex. Chem Commun (Camb) 2013; 49:10251-3. [DOI: 10.1039/c3cc44124e] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Baum AE, Park H, Wang D, Lindeman SV, Fiedler AT. Structural, spectroscopic, and electrochemical properties of nonheme Fe(II)-hydroquinonate complexes: synthetic models of hydroquinone dioxygenases. Dalton Trans 2012; 41:12244-53. [PMID: 22930005 PMCID: PMC3891569 DOI: 10.1039/c2dt31504a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Using the tris(3,5-diphenylpyrazol-1-yl)borate ((Ph2)Tp) supporting ligand, a series of mono- and dinuclear ferrous complexes containing hydroquinonate (HQate) ligands have been prepared and structurally characterized with X-ray crystallography. The monoiron(II) complexes serve as faithful mimics of the substrate-bound form of hydroquinone dioxygenases (HQDOs) - a family of nonheme Fe enzymes that catalyze the oxidative cleavage of 1,4-dihydroxybenzene units. Reflecting the variety of HQDO substrates, the synthetic complexes feature both mono- and bidentate HQate ligands. The bidentate HQates cleanly provide five-coordinate, high-spin Fe(II) complexes with the general formula [Fe((Ph2)Tp)(HL(X))] (1X), where HL(X) is a HQate(1-) ligand substituted at the 2-position with a benzimidazolyl (1A), acetyl (1B and 1C), or methoxy (1D) group. In contrast, the monodentate ligand 2,6-dimethylhydroquinone (H(2)L(F)) exhibited a greater tendency to bridge between two Fe(II) centers, resulting in formation of [Fe(2)((Ph2)Tp)(2)(μ-L(F))(MeCN)]·[2F(MeCN)]. However, addition of one equivalent of "free" pyrazole ((Ph2)pz) ligand provided the mononuclear complex, [Fe((Ph2)Tp)(HL(F))((Ph2)pz)]·[1F((Ph2)pz)], which is stabilized by an intramolecular hydrogen bond between the HL(F) and (Ph2)pz donors. Complex 1F((Ph2)pz) represents the first crystallographically-characterized example of a monoiron complex bound to an untethered HQate ligand. The geometric and electronic structures of the Fe/HQate complexes were further probed with spectroscopic (UV-vis absorption, (1)H NMR) and electrochemical methods. Cyclic voltammograms of complexes in the 1X series revealed an Fe-based oxidation between 0 and -300 mV (vs. Fc(+/0)), in addition to irreversible oxidation(s) of the HQate ligand at higher potentials. The one-electron oxidized species (1X(OX)) were examined with UV-vis absorption and electron paramagnetic resonance (EPR) spectroscopies.
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Affiliation(s)
- Amanda E. Baum
- Department of Chemistry, Marquette University, Milwaukee, WI 53201-1881
| | - Heaweon Park
- Department of Chemistry, Marquette University, Milwaukee, WI 53201-1881
| | - Denan Wang
- Department of Chemistry, Marquette University, Milwaukee, WI 53201-1881
| | | | - Adam T. Fiedler
- Department of Chemistry, Marquette University, Milwaukee, WI 53201-1881
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Bittner MM, Lindeman SV, Fiedler AT. A synthetic model of the putative Fe(II)-iminobenzosemiquinonate intermediate in the catalytic cycle of o-aminophenol dioxygenases. J Am Chem Soc 2012; 134:5460-3. [PMID: 22417231 DOI: 10.1021/ja212163t] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The oxidative ring cleavage of aromatic substrates by nonheme Fe dioxygenases is thought to involve formation of a ferrous-(substrate radical) intermediate. Here we describe the synthesis of the trigonal-bipyramdial complex Fe((Ph2)Tp)(ISQ(tBu)) (2), the first synthetic example of an iron(II) center bound to an iminobenzosemiquinonate (ISQ) radical. The unique electronic structure of this S = 3/2 complex and its one-electron oxidized derivative ([3](+)) have been established on the basis of crystallographic, spectroscopic, and computational analyses. These findings further demonstrate the viability of Fe(2+)-ISQ intermediates in the catalytic cycles of o-aminophenol dioxygenases.
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Affiliation(s)
- Michael M Bittner
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201, United States
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Bittner MM, Baus JS, Lindeman SV, Fiedler AT. Synthesis and Structural Characterization of Iron(II) Complexes with Tris(imidazolyl)phosphane Ligands: A Platform for Modeling the 3-Histidine Facial Triad of Nonheme Iron Dioxygenases. Eur J Inorg Chem 2012. [DOI: 10.1002/ejic.201101282] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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McDonald AR, Guo Y, Vu VV, Bominaar EL, Münck E, Que L. A Mononuclear Carboxylate-Rich Oxoiron(IV) Complex: a Structural and Functional Mimic of TauD Intermediate 'J'. Chem Sci 2012; 3:1680-1693. [PMID: 23267430 DOI: 10.1039/c2sc01044e] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The pentadentate ligand (n)Bu-P2DA (2(b), (n)Bu-P2DA = N-(1',1'-bis(2-pyridyl)pentyl)iminodiacetate) was designed to bind an iron center in a carboxylate-rich environment similar to that found in the active sites of TauD and other α-ketoglutarate-dependent mononuclear non-heme iron enzymes. The iron(II) complex (n)Bu(4)N[Fe(II)(Cl)((n)Bu-P2DA)] (3(b)-Cl) was synthesized and crystallographically characterized to have a 2-pyridine-2-carboxylate donor set in the plane perpendicular to the Fe-Cl bond. Reaction of 3(b)-Cl with N-heterocyclic amines such as pyridine or imidazole yielded the N-heterocyclic amine adducts [Fe(II)(N)((n)Bu-P2DA)]. These adducts in turn reacted with oxo-transfer reagents at -95 °C to afford a short-lived oxoiron(IV) complex [Fe(IV)(O)((n)Bu-P2DA)] (5(b)) in yields as high as 90% depending on the heterocycle used. Complex 5(b) exhibits near-IR absorption features (λ(max) = 770 nm) and Mossbauer parameters (δ = 0.04 mm/s; ΔE(Q) = 1.13 mm/s; D = 27±2 cm(-1)) characteristic of an S = 1 oxoiron(IV) species. Direct evidence for an Fe=O bond of 1.66 Å was found from EXAFS analysis. DFT calculations on 5(b) in its S =1 spin state afforded a geometry-optimized structure consistent with the EXAFS data. They further demonstrated that the replacement of two pyridine donors in [Fe(IV)(O)(N4Py)](2+) (N4Py = N,N-(bis(2-pyridyl)methyl)N-bis(2-pyridylmethyl)amine) with carboxylate donors in 5(b) decreased the energy gap between the ground S = 1 and the excited S = 2 states, reflecting the weaker equatorial ligand field of 5(b) and accounting for its larger D value. Complex 5(b) reacted readily with dihydrotoluene, methyldiphenylphosphine and ferrocene at -60 °C, and in all cases was approximately a 5-fold more reactive oxidant than [Fe(IV)(O)(N4Py)](2+). The reactivity differences between these two complexes may arise from a combination of electronic and steric factors. Carboxylate-rich 5(b) represents the closest structural mimic reported thus far of the oxoiron(IV) intermediate ('J') found in TauD and provides us with vital insights into the role carboxylate ligands play in modulating the spectroscopic and reactivity properties of the non-heme oxoiron(IV) moiety.
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Affiliation(s)
- Aidan R McDonald
- Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, 207 Pleasant Street S.E., Minneapolis, MN 55455
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Mijovilovich A, Hayashi H, Kawamura N, Osawa H, Bruijnincx PCA, Klein Gebbink RJM, de Groot FMF, Weckhuysen BM. Kβ Detected High-Resolution XANES of FeII and FeIII Models of the 2-His-1-Carboxylate Motif: Analysis of the Carboxylate Binding Mode. Eur J Inorg Chem 2012. [DOI: 10.1002/ejic.201101075] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Cappillino PJ, McNally JS, Wang F, Caradonna JP. The effect of varying carboxylate ligation on the electronic environment of N2Ox(x = 1–3) nonheme iron: A DFT analysis. Dalton Trans 2012; 41:474-83. [DOI: 10.1039/c1dt11199j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Cappillino PJ, Miecznikowski JR, Tyler LA, Tarves PC, McNally JS, Lo W, Kasibhatla BST, Krzyaniak MD, McCracken J, Wang F, Armstrong WH, Caradonna JP. Studies of iron(ii) and iron(iii) complexes with fac-N2O, cis-N2O2 and N2O3 donor ligands: models for the 2-His 1-carboxylate motif of non-heme iron monooxygenases. Dalton Trans 2012; 41:5662-77. [DOI: 10.1039/c2dt11096b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Iron and cobalt complexes of 4,4,9,9-tetramethyl-5,8-diazadodecane-2,11-dione dioxime ligand: Synthesis, characterization and reactivity studies. J CHEM SCI 2011. [DOI: 10.1007/s12039-011-0171-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Visvaganesan K, Ramachitra S, Palaniandavar M. Functional models for enzyme–substrate adducts of catechol dioxygenase enzymes: The Lewis basicity of facially coordinating tridentate phenolate ligands tunes the rate of dioxygenation and product selectivity. Inorganica Chim Acta 2011. [DOI: 10.1016/j.ica.2011.08.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Park H, Baus JS, Lindeman SV, Fiedler AT. Synthesis and Characterization of Fe(II) β-Diketonato Complexes with Relevance to Acetylacetone Dioxygenase: Insights into the Electronic Properties of the 3-Histidine Facial Triad. Inorg Chem 2011; 50:11978-89. [DOI: 10.1021/ic201115s] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Heaweon Park
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201-1881, United States
| | - Jacob S. Baus
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201-1881, United States
| | - Sergey V. Lindeman
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201-1881, United States
| | - Adam T. Fiedler
- Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201-1881, United States
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Bruijnincx PCA, Buurmans ILC, Huang Y, Juhász G, Viciano-Chumillas M, Quesada M, Reedijk J, Lutz M, Spek AL, Münck E, Bominaar EL, Klein Gebbink RJM. Mono- and dinuclear iron complexes of bis(1-methylimidazol-2-yl)ketone (bik): structure, magnetic properties, and catalytic oxidation studies. Inorg Chem 2011; 50:9243-55. [PMID: 21902227 PMCID: PMC3221465 DOI: 10.1021/ic200332y] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The newly synthesized dinuclear complex [Fe(III)(2)(μ-OH)(2)(bik)(4)](NO(3))(4) (1) (bik, bis(1-methylimidazol-2-yl)ketone) shows rather short Fe···Fe (3.0723(6) Å) and Fe-O distances (1.941(2)/1.949(2) Å) compared to other unsupported Fe(III)(2)(μ-OH)(2) complexes. The bridging hydroxide groups of 1 are strongly hydrogen-bonded to a nitrate anion. The (57)Fe isomer shift (δ = 0.45 mm s(-1)) and quadrupole splitting (ΔE(Q) = 0.26 mm s(-1)) obtained from Mössbauer spectroscopy are consistent with the presence of two identical high-spin iron(III) sites. Variable-temperature magnetic susceptibility studies revealed antiferromagnetic exchange (J = 35.9 cm(-1) and H = JS(1)·S(2)) of the metal ions. The optimized DFT geometry of the cation of 1 in the gas phase agrees well with the crystal structure, but both the Fe···Fe and Fe-OH distances are overestimated (3.281 and 2.034 Å, respectively). The agreement in these parameters improves dramatically (3.074 and 1.966 Å) when the hydrogen-bonded nitrate groups are included, reducing the value calculated for J by 35%. Spontaneous reduction of 1 was observed in methanol, yielding a blue [Fe(II)(bik)(3)](2+) species. Variable-temperature magnetic susceptibility measurements of [Fe(II)(bik)(3)](OTf)(2) (2) revealed spin-crossover behavior. Thermal hysteresis was observed with 2, due to a loss of cocrystallized solvent molecules, as monitored by thermogravimetric analysis. The hysteresis disappears once the solvent is fully depleted by thermal cycling. [Fe(II)(bik)(3)](OTf)(2) (2) catalyzes the oxidation of alkanes with t-BuOOH. High selectivity for tertiary C-H bond oxidation was observed with adamantane (3°/2° value of 29.6); low alcohol/ketone ratios in cyclohexane and ethylbenzene oxidation, a strong dependence of total turnover number on the presence of O(2), and a low retention of configuration in cis-1,2-dimethylcyclohexane oxidation were observed. Stereoselective oxidation of olefins with dihydrogen peroxide yielding epoxides was observed under both limiting oxidant and substrate conditions.
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Affiliation(s)
- Pieter C. A. Bruijnincx
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Inge L. C. Buurmans
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Yuxing Huang
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Gergely Juhász
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Marta Viciano-Chumillas
- Leiden Institute of Chemistry, Leiden University, Coordination and Bioinorganic Chemistry Group, P. O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Manuel Quesada
- Leiden Institute of Chemistry, Leiden University, Coordination and Bioinorganic Chemistry Group, P. O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Jan Reedijk
- Leiden Institute of Chemistry, Leiden University, Coordination and Bioinorganic Chemistry Group, P. O. Box 9502, 2300 RA Leiden, The Netherlands
- Department of Chemistry, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Martin Lutz
- Bijvoet Center for Biomolecular Research, Crystal and Structural Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Anthony L. Spek
- Bijvoet Center for Biomolecular Research, Crystal and Structural Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Eckard Münck
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Emile L. Bominaar
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Robertus J. M. Klein Gebbink
- Organic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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Synthesis and transition metal complexes of 3,3-bis(1-vinylimidazol-2-yl)propionic acid, a new N,N,O ligand suitable for copolymerisation. Inorganica Chim Acta 2011. [DOI: 10.1016/j.ica.2011.03.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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50
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PALANIANDAVAR MALLAYAN, VISVAGANESAN KUSALENDIRAN. Mononuclear non-heme iron(III) complexes of linear and tripodal tridentate ligands as functional models for catechol dioxygenases: Effect of N-alkyl substitution on regioselectivity and reaction rate. J CHEM SCI 2011. [DOI: 10.1007/s12039-011-0110-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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