1
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Khan SN, Quebedeaux B, Miliordos E. Selective conversion of methane to methanol facilitated by molecular metal-methoxy complexes via a self-correcting chemical cycle. Phys Chem Chem Phys 2024; 26:23136-23143. [PMID: 39189249 DOI: 10.1039/d4cp02189d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/28/2024]
Abstract
The controlled oxidation of methane to methanol has been an area of intense research over the past decades. Despite the efforts, the identification of an efficient catalyst with high selectivity is still elusive. Here we propose a thoroughly different strategy employing catalysts containing a metal methoxy unit. This family of catalysts has been used for the activation of C-H bonds but this is the first systematic investigation for the conversion of methane to methanol highlighting the advantages over the typically used metal oxides. Specifically, we start our investigation with an Fe(III) center coordinated by four ammonia ligands, (NH3)4FeOCH32+. Structures and energetics are reported for two mechanisms ([2+2] and proton coupled electrons transfer) and for different spin multiplicities via density functional theory, multi-reference, and coupled cluster quantum chemical calculations. The excited low-spin doublet state of this model system exhibits the best performance in terms of activation barriers and selectivity. Therefore, we then switched to the corresponding Ru(III) complex, which has a doublet ground state and manifests better performance than the doublet state of Fe(III). For both systems the activation barrier for methanol is larger than that of methane due to the interaction of the OH group of methanol with the coordinated NH3 ligands (hydrogen bonding) and/or the metal center. This observation suggests that the activation of methanol is slower, hindering its oxidation. In addition, we show that the metal-methoxy family of catalysts offers a potential mechanism that can prevent the oxidation of an activated methanol molecule (self-correcting chemical loop). This work aspires to induce experimental interest and pave the road for the development of high-performance high-selectivity methane to methanol direct conversion routes under mild conditions.
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Affiliation(s)
- Shahriar N Khan
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849-5312, USA.
| | - Brody Quebedeaux
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849-5312, USA.
| | - Evangelos Miliordos
- Department of Chemistry and Biochemistry, Auburn University, Auburn, Alabama 36849-5312, USA.
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2
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Molla M, Saha A, Barman SK, Mandal S. Monomeric Fe(III)-Hydroxo and Fe(III)-Aqua Complexes Display Oxidative Asynchronous Hydrogen Atom Abstraction Reactivity. Chemistry 2024; 30:e202401163. [PMID: 38953593 DOI: 10.1002/chem.202401163] [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: 03/22/2024] [Revised: 06/16/2024] [Accepted: 07/02/2024] [Indexed: 07/04/2024]
Abstract
This paper presents the synthesis and characterization of a series of novel monomeric aqua-ligated iron(III) complexes, [FeIII(L5R)(OH2)]2+ (R=OMe, H, Cl, NO2), supported by an amide-containing pentadentate N5 donor ligand, L5R [HL5R=2-(((1-methyl-1H-imidazol-2-yl)methyl)(pyridin-2-yl-methyl)amino)-N-(5-R-quinolin-8-yl)acetamide]. The complexes were characterized by various spectroscopic and analytical techniques, including electrochemistry and magnetic measurements. The Fe(III)-hydroxo complexes, [FeIII(L5R)(OH)]1+, were generated in situ by deprotonating the corresponding aqua complexes in a pH ~7 aqueous medium. In another way, adding one equivalent of a base to a methanolic solution of the Fe(III)-aqua complexes also produced the Fe(III)-hydroxo complexes. The study uses linoleic fatty acid as a substrate to explore the hydrogen atom abstraction (HAA) reactivity of both hydroxo and aqua complexes. The investigation highlights the substitution effect of the L5R ligand on reactivity, revealing a higher rate when an electron-withdrawing group is present. Hammett analyses and(or) determination of the asynchronicity factor (η) suggest an oxidative asynchronous concerted proton-electron transfer (CPET) pathway for the HAA reactions. Aqua complexes exhibited a higher asynchronicity in CPET, resulting in higher reaction rates than their hydroxo analogs. Overall, the work provides insights into the beneficial role of a higher imbalance in electron-transfer-proton-transfer (ET-PT) contributions in HAA reactivity.
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Affiliation(s)
- Mofijul Molla
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, 721302, India
| | - Anannya Saha
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Manauli, 140306, India
| | - Suman K Barman
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Manauli, 140306, India
| | - Sukanta Mandal
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, 721302, India
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3
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Tepaske MA, Fitterer A, Verplancke H, Delony D, Neben MC, de Bruin B, Holthausen MC, Schneider S. C-H Bond Activation by Iridium(III) and Iridium(IV) Oxo Complexes. Angew Chem Int Ed Engl 2024; 63:e202316729. [PMID: 38116899 DOI: 10.1002/anie.202316729] [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: 11/03/2023] [Revised: 12/18/2023] [Accepted: 12/19/2023] [Indexed: 12/21/2023]
Abstract
Oxidation of an iridium(III) oxo precursor enabled the structural, spectroscopic, and quantum-chemical characterization of the first well-defined iridium(IV) oxo complex. Side-by-side examination of the proton-coupled electron transfer thermochemistry revealed similar driving forces for the isostructural oxo complexes in two redox states due to compensating contributions from H+ and e- transfer. However, C-H activation of dihydroanthracene revealed significant hydrogen tunneling for the distinctly more basic iridium(III) oxo complex. Our findings complement the growing body of data that relate tunneling to ground state properties as predictors for the selectivity of C-H bond activation.
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Affiliation(s)
- Martijn A Tepaske
- Georg-August-Universität, Institut für Anorganische Chemie, Tammanstraβe 4, 37077, Göttingen, Germany
| | - Arnd Fitterer
- Institut für Anorganische und Analytische Chemie, Goethe-Universität, Max-von-Laue-Straβe 7, 60438, Frankfurt am Main, Germany
| | - Hendrik Verplancke
- Institut für Anorganische und Analytische Chemie, Goethe-Universität, Max-von-Laue-Straβe 7, 60438, Frankfurt am Main, Germany
| | - Daniel Delony
- Georg-August-Universität, Institut für Anorganische Chemie, Tammanstraβe 4, 37077, Göttingen, Germany
| | - Marc C Neben
- Georg-August-Universität, Institut für Anorganische Chemie, Tammanstraβe 4, 37077, Göttingen, Germany
| | - Bas de Bruin
- Homogeneous, Supramolecular and Bio-Inspired Catalysis Group, van't Hoff Institute for Molecular Sciences (HIMS), Science Park 904, 1098XH, Amsterdam, The Netherlands
| | - Max C Holthausen
- Institut für Anorganische und Analytische Chemie, Goethe-Universität, Max-von-Laue-Straβe 7, 60438, Frankfurt am Main, Germany
| | - Sven Schneider
- Georg-August-Universität, Institut für Anorganische Chemie, Tammanstraβe 4, 37077, Göttingen, Germany
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4
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Lindner H, Amberg WM, Carreira EM. Iron-Mediated Photochemical Anti-Markovnikov Hydroazidation of Unactivated Olefins. J Am Chem Soc 2023; 145:22347-22353. [PMID: 37811819 PMCID: PMC10591317 DOI: 10.1021/jacs.3c09122] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Indexed: 10/10/2023]
Abstract
Unactivated olefins are converted to alkyl azides with bench-stable NaN3 in the presence of FeCl3·6H2O under blue-light irradiation. The products are obtained with anti-Markovnikov selectivity, and the reaction can be performed under mild ambient conditions in the presence of air and moisture. The transformation displays broad functional group tolerance, which renders it suitable for functionalization of complex molecules. Mechanistic investigations are conducted to provide insight into the hydroazidation reaction and reveal the role of water from the iron hydrate as the H atom source.
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Affiliation(s)
- Henry Lindner
- Department of Chemistry and
Applied Biosciences, Laboratory of Organic Chemistry, ETH Zürich, 8093 Zurich, Switzerland
| | - Willi M. Amberg
- Department of Chemistry and
Applied Biosciences, Laboratory of Organic Chemistry, ETH Zürich, 8093 Zurich, Switzerland
| | - Erick M. Carreira
- Department of Chemistry and
Applied Biosciences, Laboratory of Organic Chemistry, ETH Zürich, 8093 Zurich, Switzerland
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5
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Palit D, Kundu S, Pain PK, Sarma R, Manna D. A Chemical Model of a TET Enzyme for Selective Oxidation of Hydroxymethyl Cytosine to Formyl Cytosine. Inorg Chem 2023. [PMID: 37339080 DOI: 10.1021/acs.inorgchem.3c00063] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2023]
Abstract
Methylation/demethylation of cytosines in DNA is central to epigenetics, which plays crucial roles in the regulation of about half of all human genes. Although the methylation mechanism, which downregulates gene expression, has been sufficiently decoded; the demethylation pathway, which upregulates gene expression, still holds questions to be answered. Demethylation of 5-methylcytosine by ten-eleven translocation (TET) enzymes yields understudied but epigenetically relevant intermediates, 5-hydroxymethyl (5-hmC), 5-formyl (5-fC), and 5-carboxyl (5-caC) cytosines. Here we report an iron complex, FeIIITAML (TAML = tetraamido macrocyclic ligand), which can facilitate selective oxidation of 5-hmC to its oxidative derivatives by forming a high-valent Fe-oxo intermediate in the presence of H2O2 under physiologically relevant conditions. Detailed HPLC analyses supported by a wide reaction condition optimization for the 5-hmC → 5-fC oxidation provides us with a chemical model of the TET enzyme. This study shines light on future efforts for a better understanding of the roles of 5-hmC and the TET enzyme mechanism and potentially novel therapeutic methods.
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Affiliation(s)
- Dipanwita Palit
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal, MP 462066, India
| | - Shubhankar Kundu
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal, MP 462066, India
| | - Pritam Kumar Pain
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal, MP 462066, India
| | - Rajdeep Sarma
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal, MP 462066, India
| | - Debasish Manna
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal, MP 462066, India
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6
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Misawa-Suzuki T, Nagao H. Ru(IV)-Ru(IV) complexes having the doubly oxido-bridged core with a bridging carbonato or hydrogencarbonato ligand. Dalton Trans 2023; 52:2863-2871. [PMID: 36762568 DOI: 10.1039/d2dt04080h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Ru(IV)-Ru(IV) complexes having the doubly oxido-bridged diamond core with a bridging carbonato or hydrogencarbonato ligand, [{RuIV(ebpma)}2(μ-O)2(μ-O2CO(H)m)]Xn (ebpma; ethylbis(2-pyridylmethyl)amine, m = 0; [IV,IV]X2 (X = PF6, ClO4), m = 1; [IV,IV_1H](ClO4)3), were isolated via the oxidation of the corresponding carbonato-bridged Ru(III)-Ru(IV) complex ([III,IV]+), and "[IV,IV](ClO4)2 and [IV,IV_1H](ClO4)3" were structurally characterized. The electrochemical and spectroscopic properties of [IV,IV]2+ and [IV,IV_1H]3+ were investigated both in organic solvents and aqueous solutions. The reactivity toward organic solvents having (a) methyl group(s) and reactions with organic substrates were studied as well. This should be the first time when systematic comparisons of the Ru(IV)-Ru(IV) species and corresponding Ru(III)-Ru(IV) complexes in the same tridentate ligand system were made.
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Affiliation(s)
- Tomoyo Misawa-Suzuki
- Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioicho Chiyoda-ku, Tokyo 102-8554, Japan.
| | - Hirotaka Nagao
- Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioicho Chiyoda-ku, Tokyo 102-8554, Japan.
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7
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Karmalkar DG, Larson VA, Malik DD, Lee YM, Seo MS, Kim J, Vasiliauskas D, Shearer J, Lehnert N, Nam W. Preparation and Characterization of a Formally Ni IV-Oxo Complex with a Triplet Ground State and Application in Oxidation Reactions. J Am Chem Soc 2022; 144:22698-22712. [PMID: 36454200 DOI: 10.1021/jacs.2c10196] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
High-valent first-row transition-metal-oxo complexes are important intermediates in biologically and chemically relevant oxidative transformations of organic molecules and in the water splitting reaction in (artificial) photosynthesis. While high-valent Fe- and Mn-oxo complexes have been characterized in detail, much less is known about their analogues with late transition metals. In this study, we present the synthesis and detailed characterization of a unique mononuclear terminal Ni-O complex. This compound, [Ni(TAML)(O)(OH)]3-, is characterized by an intense charge-transfer (CT) band around 730 nm and has an St = 1 ground state, as determined by magnetic circular dichroism spectroscopy. From extended X-ray absorption fine structure (EXAFS), the Ni-O bond distance is 1.84 Å. Ni K edge XAS data indicate that the complex contains a Ni(III) center, which results from an unusually large degree of Ni-O π-bond inversion, with one hole located on the oxo ligand. The complex is therefore best described as a low-spin Ni(III) complex (S = 1/2) with a bound oxyl (O•-) ligand (S = 1/2), where the spins of Ni and oxyl are ferromagnetically coupled, giving rise to the observed St = 1 ground state. This bonding description is roughly equivalent to the presence of a Ni-O single (σ) bond. Reactivity studies show that [Ni(TAML)(O)(OH)]3- is a strong oxidant capable of oxidizing thioanisole and styrene derivatives with large negative ρ values in the Hammett plot, indicating its electrophilic nature. The intermediate also shows high reactivity in C-H bond activation of hydrocarbons with a kinetic isotope effect of 7.0(3) in xanthene oxidation.
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Affiliation(s)
- Deepika G Karmalkar
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Virginia A Larson
- Department of Chemistry and Department of Biophysics, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Deesha D Malik
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Yong-Min Lee
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Mi Sook Seo
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Jin Kim
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Dovydas Vasiliauskas
- Department of Chemistry, Trinity University, San Antonio, Texas 78212-7200, United States
| | - Jason Shearer
- Department of Chemistry, Trinity University, San Antonio, Texas 78212-7200, United States
| | - Nicolai Lehnert
- Department of Chemistry and Department of Biophysics, University of Michigan, Ann Arbor, Michigan 48109-1055, United States
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
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8
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Karbalaei S, Franke A, Jordan A, Rose C, Pokkuluri PR, Beyers RJ, Zahl A, Ivanović‐Burmazović I, Goldsmith CR. A Highly Water‐ and Air‐Stable Iron‐Containing MRI Contrast Agent Sensor for H
2
O
2. Chemistry 2022; 28:e202201179. [DOI: 10.1002/chem.202201179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Indexed: 11/12/2022]
Affiliation(s)
- Sana Karbalaei
- Department of Chemistry and Biochemistry Auburn University Auburn AL 36849 USA
| | - Alicja Franke
- Department of Chemistry Ludwig-Maximilians-Universität München 81377 München Germany
| | - Aubree Jordan
- Department of Chemistry and Biochemistry Auburn University Auburn AL 36849 USA
| | - Cayla Rose
- Department of Chemistry and Biochemistry Auburn University Auburn AL 36849 USA
| | - P. Raj Pokkuluri
- Department of Chemistry and Biochemistry Auburn University Auburn AL 36849 USA
| | - Ronald J. Beyers
- Auburn University Magnetic Resonance Imaging Research Center Auburn AL 36849 USA
| | - Achim Zahl
- Department of Chemistry and Pharmacy Friedrich-Alexander University Erlangen-Nuremberg 91058 Erlangen Germany
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9
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Wu GL, Zheng CY. MODELS FOR LIPOXYGENASE WITH TWO ALKOXIDE–Fe(III) CENTERS: SYNTHESIS, STRUCTURES, AND PROPERTIES. J STRUCT CHEM+ 2022. [DOI: 10.1134/s0022476622040151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Das B, Al-Hunaiti A, Carey A, Lidin S, Demeshko S, Repo T, Nordlander E. A di‑iron(III) μ-oxido complex as catalyst precursor in the oxidation of alkanes and alkenes. J Inorg Biochem 2022; 231:111769. [DOI: 10.1016/j.jinorgbio.2022.111769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 02/10/2022] [Accepted: 02/10/2022] [Indexed: 11/30/2022]
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11
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Panda C, Doyle LM, Gericke R, McDonald AR. Rapid Iron(III)-Fluoride-Mediated Hydrogen Atom Transfer. Angew Chem Int Ed Engl 2021; 60:26281-26286. [PMID: 34582619 PMCID: PMC9298026 DOI: 10.1002/anie.202112683] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Indexed: 01/08/2023]
Abstract
We anticipate high-valent metal-fluoride species will be highly effective hydrogen atom transfer (HAT) oxidants because of the magnitude of the H-F bond (in the product) that drives HAT oxidation. We prepared a dimeric FeIII (F)-F-FeIII (F) complex (1) by reacting [FeII (NCCH3 )2 (TPA)](ClO4 )2 (TPA=tris(2-pyridylmethyl)amine) with difluoro(phenyl)-λ3 -iodane (difluoroiodobenzene). 1 was a sluggish oxidant, however, it was readily activated by reaction with Lewis or Brønsted acids to yield a monomeric [FeIII (TPA)(F)(X)]+ complex (2) where X=F/OTf. 1 and 2 were characterized using NMR, EPR, UV/Vis, and FT-IR spectroscopies and mass spectrometry. 2 was a remarkably reactive FeIII reagent for oxidative C-H activation, demonstrating reaction rates for hydrocarbon HAT comparable to the most reactive FeIII and FeIV oxidants.
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Affiliation(s)
- Chakadola Panda
- School of ChemistryTrinity College DublinThe University of Dublin, College GreenDublin 2Ireland
| | - Lorna M. Doyle
- School of ChemistryTrinity College DublinThe University of Dublin, College GreenDublin 2Ireland
| | - Robert Gericke
- School of ChemistryTrinity College DublinThe University of Dublin, College GreenDublin 2Ireland
- Current address: Helmholtz-Zentrum Dresden-Rossendorf e. V.Institute of Resource EcologyBautzner Landstrasse 40001328DresdenGermany
| | - Aidan R. McDonald
- School of ChemistryTrinity College DublinThe University of Dublin, College GreenDublin 2Ireland
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12
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Panda C, Doyle LM, Gericke R, McDonald AR. Rapid Iron(III)−Fluoride‐Mediated Hydrogen Atom Transfer. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202112683] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Chakadola Panda
- School of Chemistry Trinity College Dublin The University of Dublin, College Green Dublin 2 Ireland
| | - Lorna M. Doyle
- School of Chemistry Trinity College Dublin The University of Dublin, College Green Dublin 2 Ireland
| | - Robert Gericke
- School of Chemistry Trinity College Dublin The University of Dublin, College Green Dublin 2 Ireland
- Current address: Helmholtz-Zentrum Dresden-Rossendorf e. V. Institute of Resource Ecology Bautzner Landstrasse 400 01328 Dresden Germany
| | - Aidan R. McDonald
- School of Chemistry Trinity College Dublin The University of Dublin, College Green Dublin 2 Ireland
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13
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Karmalkar DG, Seo MS, Lee YM, Kim Y, Lee E, Sarangi R, Fukuzumi S, Nam W. Deeper Understanding of Mononuclear Manganese(IV)-Oxo Binding Brønsted and Lewis Acids and the Manganese(IV)-Hydroxide Complex. Inorg Chem 2021; 60:16996-17007. [PMID: 34705465 DOI: 10.1021/acs.inorgchem.1c02119] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Binding of Lewis acidic metal ions and Brønsted acid at the metal-oxo group of high-valent metal-oxo complexes enhances their reactivities significantly in oxidation reactions. However, such a binding of Lewis acids and proton at the metal-oxo group has been questioned in several cases and remains to be clarified. Herein, we report the synthesis, characterization, and reactivity studies of a mononuclear manganese(IV)-oxo complex binding triflic acid, {[(dpaq)MnIV(O)]-HOTf}+ (1-HOTf). First, 1-HOTf was synthesized and characterized using various spectroscopic techniques, including resonance Raman (rRaman) and X-ray absorption spectroscopy/extended X-ray absorption fine structure. In particular, in rRaman experiments, we observed a linear correlation between the Mn-O stretching frequencies of 1-HOTf (e.g., νMn-O at ∼793 cm-1) and 1-Mn+ (Mn+ = Ca2+, Zn2+, Lu3+, Al3+, or Sc3+) and the Lewis acidities of H+ and Mn+ ions, suggesting that H+ and Mn+ bind at the metal-oxo moiety of [(dpaq)MnIV(O)]+. Interestingly, a single-crystal structure of 1-HOTf was obtained by X-ray diffraction analysis, but the structure was not an expected Mn(IV)-oxo complex but a Mn(IV)-hydroxide complex, [(dpaq)MnIV(OH)](OTf)2 (4), with a Mn-O bond distance of 1.8043(19) Å and a Mn-O stretch at 660 cm-1. More interestingly, 4 reverted to 1-HOTf upon dissolution, demonstrating that 1-HOTf and 4 are interconvertible depending on the physical states, such as 1-HOTf in solution and 4 in isolated solid. The reactivity of 1-HOTf was investigated in hydrogen atom transfer (HAT) and oxygen atom transfer (OAT) reactions and then compared with those of 1-Mn+ complexes; an interesting correlation between the Mn-O stretching frequencies of 1-HOTf and 1-Mn+ and their reactivities in the OAT and HAT reactions is reported for the first time in this study.
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Affiliation(s)
- Deepika G Karmalkar
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Mi Sook Seo
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Yong-Min Lee
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Youngsuk Kim
- Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Eunsung Lee
- Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Ritimukta Sarangi
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
| | - Shunichi Fukuzumi
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
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14
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Schmidl D, Jonasson NSW, Korytiaková E, Carell T, Daumann LJ. Biomimetic Iron Complex Achieves TET Enzyme Reactivity**. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202107277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- David Schmidl
- Department Chemie Ludwig-Maximilians-University München Butenandtstr. 5–13, Haus D München Germany
| | - Niko S. W. Jonasson
- Department Chemie Ludwig-Maximilians-University München Butenandtstr. 5–13, Haus D München Germany
| | - Eva Korytiaková
- Department Chemie Ludwig-Maximilians-University München Butenandtstr. 5–13, Haus D München Germany
| | - Thomas Carell
- Department Chemie Ludwig-Maximilians-University München Butenandtstr. 5–13, Haus D München Germany
| | - Lena J. Daumann
- Department Chemie Ludwig-Maximilians-University München Butenandtstr. 5–13, Haus D München Germany
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15
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Schmidl D, Jonasson NSW, Korytiaková E, Carell T, Daumann LJ. Biomimetic Iron Complex Achieves TET Enzyme Reactivity*. Angew Chem Int Ed Engl 2021; 60:21457-21463. [PMID: 34181314 PMCID: PMC8518650 DOI: 10.1002/anie.202107277] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/23/2021] [Indexed: 12/12/2022]
Abstract
The epigenetic marker 5-methyl-2'-deoxycytidine (5mdC) is the most prevalent modification to DNA. It is removed inter alia via an active demethylation pathway: oxidation by Ten-Eleven Translocation 5-methyl cytosine dioxygenase (TET) and subsequent removal via base excision repair or direct demodification. Recently, we have shown that the synthetic iron(IV)-oxo complex [FeIV (O)(Py5 Me2 H)]2+ (1) can serve as a biomimetic model for TET by oxidizing the nucleobase 5-methyl cytosine (5mC) to its natural metabolites. In this work, we demonstrate that nucleosides and even short oligonucleotide strands can also serve as substrates, using a range of HPLC and MS techniques. We found that the 5-position of 5mC is oxidized preferably by 1, with side reactions occurring only at the strand ends of the used oligonucleotides. A detailed study of the reactivity of 1 towards nucleosides confirms our results; that oxidation of the anomeric center (1') is the most common side reaction.
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Affiliation(s)
- David Schmidl
- Department ChemieLudwig-Maximilians-University MünchenButenandtstr. 5–13, Haus DMünchenGermany
| | - Niko S. W. Jonasson
- Department ChemieLudwig-Maximilians-University MünchenButenandtstr. 5–13, Haus DMünchenGermany
| | - Eva Korytiaková
- Department ChemieLudwig-Maximilians-University MünchenButenandtstr. 5–13, Haus DMünchenGermany
| | - Thomas Carell
- Department ChemieLudwig-Maximilians-University MünchenButenandtstr. 5–13, Haus DMünchenGermany
| | - Lena J. Daumann
- Department ChemieLudwig-Maximilians-University MünchenButenandtstr. 5–13, Haus DMünchenGermany
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16
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Malik DD, Chandra A, Seo MS, Lee YM, Farquhar ER, Mebs S, Dau H, Ray K, Nam W. Formation of cobalt-oxygen intermediates by dioxygen activation at a mononuclear nonheme cobalt(ii) center. Dalton Trans 2021; 50:11889-11898. [PMID: 34373886 PMCID: PMC8499697 DOI: 10.1039/d1dt01996a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A mononuclear nonheme cobalt(ii) complex, [(TMG3tren)CoII(OTf)](OTf) (1), activates dioxygen in the presence of hydrogen atom donor substrates, such as tetrahydrofuran and cyclohexene, resulting in the generation of a cobalt(ii)-alkylperoxide intermediate (2), which then converts to the previously reported cobalt(iv)-oxo complex, [(TMG3tren)CoIV(O)]2+-(Sc(OTf)3)n (3), in >90% yield upon addition of a redox-inactive metal ion, Sc(OTf)3. Intermediates 2 and 3 represent the cobalt analogues of the proposed iron(ii)-alkylperoxide precursor that converts to an iron(iv)-oxo intermediate via O-O bond heterolysis in pterin-dependent nonheme iron oxygenases. In reactivity studies, 2 shows an amphoteric reactivity in electrophilic and nucleophilic reactions, whereas 3 is an electrophilic oxidant. To the best of our knowledge, the present study reports the first example showing the generation of cobalt-oxygen intermediates by activating dioxygen at a cobalt(ii) center and the reactivities of the cobalt-oxygen intermediates in oxidation reaction.
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Affiliation(s)
- Deesha D Malik
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea.
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17
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Synthesis, reactivity, and DFT studies of a series of non-heme alkoxoiron(III) complexes as models for lipoxygenase. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2021.120472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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18
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Dobbelaar E, Rauber C, Bonck T, Kelm H, Schmitz M, de Waal Malefijt ME, Klein JEMN, Krüger HJ. Combining Structural with Functional Model Properties in Iron Synthetic Analogue Complexes for the Active Site in Rabbit Lipoxygenase. J Am Chem Soc 2021; 143:13145-13155. [PMID: 34383499 DOI: 10.1021/jacs.1c04422] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Iron complexes that model the structural and functional properties of the active iron site in rabbit lipoxygenase are described. The ligand sphere of the mononuclear pseudo-octahedral cis-(carboxylato)(hydroxo)iron(III) complex, which is completed by a tetraazamacrocyclic ligand, reproduces the first coordination shell of the active site in the enzyme. In addition, two corresponding iron(II) complexes are presented that differ in the coordination of a water molecule. In their structural and electronic properties, both the (hydroxo)iron(III) and the (aqua)iron(II) complex reflect well the only two essential states found in the enzymatic mechanism of peroxidation of polyunsaturated fatty acids. Furthermore, the ferric complex is shown to undergo hydrogen atom abstraction reactions with O-H and C-H bonds of suitable substrates, and the bond dissociation free energy of the coordinated water ligand of the ferrous complex is determined to be 72.4 kcal·mol-1. Theoretical investigations of the reactivity support a concerted proton-coupled electron transfer mechanism in close analogy to the initial step in the enzymatic mechanism. The propensity of the (hydroxo)iron(III) complex to undergo H atom abstraction reactions is the basis for its catalytic function in the aerobic peroxidation of 2,4,6-tri(tert-butyl)phenol and its role as a radical initiator in the reaction of dihydroanthracene with oxygen.
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Affiliation(s)
- Emiel Dobbelaar
- Department of Chemistry, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Christian Rauber
- Department of Chemistry, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Thorsten Bonck
- Department of Chemistry, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Harald Kelm
- Department of Chemistry, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Markus Schmitz
- Department of Chemistry, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
| | - Matina Eloïse de Waal Malefijt
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 9, 9747 AG Groningen, The Netherlands
| | - Johannes E M N Klein
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 9, 9747 AG Groningen, The Netherlands
| | - Hans-Jörg Krüger
- Department of Chemistry, Technische Universität Kaiserslautern, 67663 Kaiserslautern, Germany
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19
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Li XX, Xue SS, Lu X, Seo MS, Lee YM, Kim WS, Cho KB, Nam W. Ligand Architecture Perturbation Influences the Reactivity of Nonheme Iron(V)-Oxo Tetraamido Macrocyclic Ligand Complexes: A Combined Experimental and Theoretical Study. Inorg Chem 2021; 60:4058-4067. [PMID: 33645218 DOI: 10.1021/acs.inorgchem.1c00110] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Iron(V)-oxo complexes bearing negatively charged tetraamido macrocyclic ligands (TAMLs) have provided excellent opportunities to investigate the chemical properties and the mechanisms of oxidation reactions of mononuclear nonheme iron(V)-oxo intermediates. Herein, we report the differences in chemical properties and reactivities of two iron(V)-oxo TAML complexes differing by modification on the "Head" part of the TAML framework; one has a phenyl group at the "Head" part (1), whereas the other has four methyl groups replacing the phenyl ring (2). The reactivities of 1 and 2 in both C-H bond activation reactions, such as hydrogen atom transfer (HAT) of 1,4-cyclohexadiene, and oxygen atom transfer (OAT) reactions, such as the oxidation of thioanisole and its derivatives, were compared experimentally. Under identical reaction conditions, 1 showed much greater reactivity than 2, such as a 102-fold decrease in HAT and a 105-fold decrease in OAT by replacing the phenyl group (i.e., 1) with four methyl groups (i.e., 2). Then, density functional theory calculations were performed to rationalize the reactivity differences between 1 and 2. Computations reproduced the experimental findings well and revealed that the replacement of the phenyl group in 1 with four methyl groups in 2 not only increased the steric hindrance but also enlarged the energy gap between the electron-donating orbital and the electron-accepting orbital. These two factors, steric hindrance and the orbital energy gap, resulted in differences in the reduction potentials of 1 and 2 and their reactivities in oxidation reactions.
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Affiliation(s)
- Xiao-Xi Li
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Shan-Shan Xue
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Xiaoyan Lu
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Mi Sook Seo
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Yong-Min Lee
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Won-Suk Kim
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Kyung-Bin Cho
- Department of Chemistry, Jeonbuk National University, Jeonju 54896, Korea
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea.,School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China
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20
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Narulkar DD, Ansari A, Vardhaman AK, Harmalkar SS, Lingamallu G, Dhavale VM, Sankaralingam M, Das S, Kumar P, Dhuri SN. A side-on Mn(III)-peroxo supported by a non-heme pentadentate N 3Py 2 ligand: synthesis, characterization and reactivity studies. Dalton Trans 2021; 50:2824-2831. [PMID: 33533342 DOI: 10.1039/d0dt03706k] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A mononuclear manganese(iii)-peroxo complex [MnIII(N3Py2)(O2)]+ (1a) bearing a non-heme N,N'-dimethyl-N-(2-(methyl(pyridin-2-ylmethyl)amino)ethyl)-N'-(pyridin-2-ylmethyl)ethane-1,2-diamine (N3Py2) ligand was synthesized by the reaction of [Mn(N3Py2)(H2O)](ClO4)2 (1) with hydrogen peroxide and triethylamine in CH3CN at 25 °C. The reactivity of 1a in aldehyde deformylation using 2-phenyl propionaldehyde (2-PPA) was studied and the reaction kinetics was monitored by UV-visible spectroscopy. A kinetic isotope effect (KIE) = 1.7 was obtained in the reaction of 1a with 2-PPA and α-[D1]-PPA, suggesting nucleophilic character of 1a. The activation parameters ΔH‡ and ΔS‡ were determined using the Eyring plot while Ea was obtained from the Arrhenius equation by performing the reaction between 288 and 303 K. Hammett constants (σp) of para-substituted benzaldehydes p-X-Ph-CHO (X = Cl, F, H, and Me) were linear with a slope (ρ) = 3.0. Computational study suggested that the side-on structure of 1a is more favored over the end-on structure and facilitates the reactivity of 1a.
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Affiliation(s)
- Dattaprasad D Narulkar
- School of Chemical Sciences, Goa University, Goa-403206, India. and Department of Chemistry, Dnyanprassarak Mandal's College and Research Centre, Assagao, Goa-403507, India
| | - Azaj Ansari
- Department of Chemistry, Central University of Haryana, Mahendergarh-123031, Haryana, India
| | - Anil Kumar Vardhaman
- Polymers & Functional Materials Division, CSIR-Indian Institute of Chemical Technology, Uppal Road, Tarnaka, Hyderabad-500007, India
| | | | - Giribabu Lingamallu
- Polymers & Functional Materials Division, CSIR-Indian Institute of Chemical Technology, Uppal Road, Tarnaka, Hyderabad-500007, India
| | - Vishal M Dhavale
- CSIR-Central Electrochemical Research Institute, CSIR Madras Complex, Taramani, Chennai-600 113, India
| | - Muniyandi Sankaralingam
- Bioinspired & Biomimetic Inorganic Chemistry Lab, Department of Chemistry, National Institute of Technology Calicut, Kozhikode, Kerala 673601, India
| | - Sandip Das
- Indian Institute of Science Education and Research (IISER), Tirupati-517507, India
| | - Pankaj Kumar
- Indian Institute of Science Education and Research (IISER), Tirupati-517507, India
| | - Sunder N Dhuri
- School of Chemical Sciences, Goa University, Goa-403206, India.
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21
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Hong YH, Jang Y, Ezhov R, Seo MS, Lee YM, Pandey B, Hong S, Pushkar Y, Fukuzumi S, Nam W. A Highly Reactive Chromium(V)–Oxo TAML Cation Radical Complex in Electron Transfer and Oxygen Atom Transfer Reactions. ACS Catal 2021. [DOI: 10.1021/acscatal.1c00079] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Young Hyun Hong
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Yuri Jang
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Roman Ezhov
- Department of Physics and Astronomy, Purdue University 525 Northwestern Avenue, West Lafayette, Indiana 47907, United States
| | - Mi Sook Seo
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Yong-Min Lee
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Bhawana Pandey
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Seungwoo Hong
- Department of Chemistry, Sookmyung Women’s University, Seoul 04310, Korea
| | - Yulia Pushkar
- Department of Physics and Astronomy, Purdue University 525 Northwestern Avenue, West Lafayette, Indiana 47907, United States
| | - Shunichi Fukuzumi
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
- School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an, People’s Republic of China
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22
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Wong KH, Cheung WM, Pham HL, So YM, Sung HHY, Williams ID, Leung WH. Oxidizing Cerium(IV) Alkoxide Complexes Supported by the Kläui Ligand [Co(η 5-C 5H 5){P(O)(OEt) 2} 3] -: Synthesis, Structure, and Redox Reactivity. Inorg Chem 2021; 60:2261-2270. [PMID: 33499604 DOI: 10.1021/acs.inorgchem.0c03105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tetravalent cerium alkoxide complexes supported by the Kläui tripodal ligand [Co(η5-C5H5){P(O)(OEt)2}3]- (LOEt-) have been synthesized, and their nucleophilic and redox reactivity have been studied. Treatment of the Ce(IV) oxo complex [CeIV(LOEt)2(O)(H2O)]·MeCONH2 (1) with iPrOH or reaction of [CeIV(LOEt)2Cl2] (2) with Ag2O in iPrOH afforded the Ce(IV) dialkoxide complex [CeIV(LOEt)2(OiPr)2] (3-iPr). The methoxide and ethoxide analogues [CeIV(LOEt)2(OR)2] (R = Me (3-Me), Et (3-Et)) have been prepared similarly from 2 and Ag2O in ROH. Reaction of 3-iPr with an equimolar amount of 2 yielded a new Ce(IV) complex that was formulated as the chloro-alkoxide complex [CeIV(LOEt)2(OiPr)Cl] (4). Treatment of 3-iPr with HX and methyl triflate (MeOTf) afforded [Ce(LOEt)2X2] (X- = Cl-, NO3-, PhO-) and [CeIV(LOEt)2(OTf)2], respectively, whereas treatment with excess CO2 in hexane led to isolation of the Ce(IV) carbonate [CeIV(LOEt)2(CO3)]. 3-iPr reacted with water in hexane to give a Ce(III) complex and a Ce(IV) species, presumably the reported tetranuclear oxo cluster [CeIV4(LOEt)4(O)5(OH)2]. The Ce(IV) alkoxide complexes are capable of oxidizing substituted phenols, possibly via a proton-coupled electron transfer pathway. Treatment of 3-iPr with ArOH afforded the Ce(III) aryloxide complexes [CeIII(LOEt)2(OAr)] (Ar = 2,4,6-tri-tert-butylphenyl (5), 2,6-diphenylphenyl (6)). On the other hand, a Ce(III) complex containing a monodeprotonated 2,2'-biphenol ligand, [CeIII(LOEt)2(tBu4C12H4O2H)] (7) (tBu4C12H4O2H2 = 4,4',6,6'-tetra-tert-butyl-2,2'-biphenol), was isolated from the reaction of 3-iPr with 2,4-di-tert-butylphenol. The crystal structures of complexes 3-iPr, 3-Me, 3-Et, and 5-7 have been determined.
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Affiliation(s)
- Kai-Hong Wong
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Wai-Man Cheung
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Hoang-Long Pham
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Yat-Ming So
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Herman H-Y Sung
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Ian D Williams
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Wa-Hung Leung
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
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23
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Boniolo M, Chernev P, Cheah MH, Heizmann PA, Huang P, Shylin SI, Salhi N, Hossain MK, Gupta AK, Messinger J, Thapper A, Lundberg M. Electronic and geometric structure effects on one-electron oxidation of first-row transition metals in the same ligand framework. Dalton Trans 2021; 50:660-674. [PMID: 33325945 DOI: 10.1039/d0dt03695a] [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
Developing new transition metal catalysts requires understanding of how both metal and ligand properties determine reactivity. Since metal complexes bearing ligands of the Py5 family (2,6-bis-[(2-pyridyl)methyl]pyridine) have been employed in many fields in the past 20 years, we set out here to understand their redox properties by studying a series of base metal ions (M = Mn, Fe, Co, and Ni) within the Py5OH (pyridine-2,6-diylbis[di-(pyridin-2-yl)methanol]) variant. Both reduced (MII) and the one-electron oxidized (MIII) species were carefully characterized using a combination of X-ray crystallography, X-ray absorption spectroscopy, cyclic voltammetry, and density-functional theory calculations. The observed metal-ligand interactions and electrochemical properties do not always follow consistent trends along the periodic table. We demonstrate that this observation cannot be explained by only considering orbital and geometric relaxation, and that spin multiplicity changes needed to be included into the DFT calculations to reproduce and understand these trends. In addition, exchange reactions of the sixth ligand coordinated to the metal, were analysed. Finally, by including published data of the extensively characterised Py5OMe (pyridine-2,6-diylbis[di-(pyridin-2-yl)methoxymethane])complexes, the special characteristics of the less common Py5OH ligand were extracted. This comparison highlights the non-innocent effect of the distal OH functionalization on the geometry, and consequently on the electronic structure of the metal complexes. Together, this gives a complete analysis of metal and ligand degrees of freedom for these base metal complexes, while also providing general insights into how to control electrochemical processes of transition metal complexes.
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Affiliation(s)
- Manuel Boniolo
- Molecular Biomimetics, Department of Chemistry -Ångström Laboratory, Uppsala University, 75120 Uppsala, Sweden.
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24
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Gericke R, Doyle LM, Farquhar ER, McDonald AR. Oxo-Free Hydrocarbon Oxidation by an Iron(III)-Isoporphyrin Complex. Inorg Chem 2020; 59:13952-13961. [PMID: 32955871 DOI: 10.1021/acs.inorgchem.0c01618] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Metal-halides that perform proton coupled electron-transfer (PCET) oxidation are an important new class of high-valent oxidant. In investigating metal-dihalides, we reacted [FeIII(Cl)(T(OMe)PP)] (1, T(OMe)PP = meso-tetra(4-methoxyphenyl)porphyrinyl) with (dichloroiodo)benzene. An FeIII-meso-chloro-isoporphyrin complex [FeIII(Cl)2(T(OMe)PP-Cl)] (2) was obtained. 2 was characterized by electronic absorption, 1H NMR, EPR, and X-ray absorption spectroscopies and mass spectrometry with support from computational analyses. 2 was reacted with a series of hydrocarbon substrates. The measured kinetic data exhibited a nonlinear behavior, whereby the oxidation followed a hydrogen-atom-transfer (HAT) PCET mechanism. The meso-chlorine atom was identified as the HAT agent. In one case, a halogenated product was identified by mass spectrometry. Our findings demonstrate that oxo-free hydrocarbon oxidation with heme systems is possible and show the potential for iron-dihalides in oxidative hydrocarbon halogenation.
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Affiliation(s)
- Robert Gericke
- School of Chemistry, College Green, Trinity College Dublin, The University of Dublin, Dublin 2 D02 PN40, Ireland
| | - Lorna M Doyle
- School of Chemistry, College Green, Trinity College Dublin, The University of Dublin, Dublin 2 D02 PN40, Ireland
| | - Erik R Farquhar
- National Synchrotron Light Source II, Brookhaven National Laboratory, Case Western Reserve University Center for Synchrotron Biosciences, Upton, New York 11973, United States
| | - Aidan R McDonald
- School of Chemistry, College Green, Trinity College Dublin, The University of Dublin, Dublin 2 D02 PN40, Ireland
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25
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Chen D, Berhane IA, Chemler SR. Copper-Catalyzed Enantioselective Hydroalkoxylation of Alkenols for the Synthesis of Cyclic Ethers. Org Lett 2020; 22:7409-7414. [PMID: 32496794 PMCID: PMC7541751 DOI: 10.1021/acs.orglett.0c01691] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The copper-catalyzed enantioselective intramolecular hydroalkoxylation of unactivated alkenes for the synthesis of tetrahydrofurans, phthalans, isochromans, and morpholines from 4- and 5-alkenols is reported. The substrate scope is complementary to existing enantioselective alkene hydroalkoxylations and is broad with respect to substrate backbone and alkene substitution. The asymmetric induction and isotopic labeling studies support a polar/radical mechanism involving enantioselective oxycupration followed by C-[Cu] homolysis and hydrogen atom transfer. Synthesis of the antifungal insecticide furametpyr was accomplished.
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Affiliation(s)
- Dake Chen
- Chemistry Department, State University of New York at Buffalo, Buffalo, New York 14260, United States
| | - Ilyas A Berhane
- Chemistry Department, State University of New York at Buffalo, Buffalo, New York 14260, United States
| | - Sherry R Chemler
- Chemistry Department, State University of New York at Buffalo, Buffalo, New York 14260, United States
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26
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Mondal P, McDonald AR. Phenol Oxidation by a Nickel(III)-Fluoride Complex: Exploring the Influence of the Proton Accepting Ligand in PCET Oxidation. Chemistry 2020; 26:10083-10089. [PMID: 32567726 DOI: 10.1002/chem.202002135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/15/2020] [Indexed: 11/05/2022]
Abstract
In order to gain insight into the influence of the H+ -accepting terminal ligand in high-valent oxidant mediated proton coupled electron transfer (PCET) reactions, the reactivity of a high valent nickel-fluoride complex [NiIII (F)(L)] (2, L=N,N'-(2,6-dimethylphenyl)-2,6-pyridinecarboxamidate) with substituted phenols was explored. Analysis of kinetic data from these reactions (Evans-Polanyi, Hammett, and Marcus plots, and KIE measurements) and the formed products show that 2 reacted with electron rich phenols through a hydrogen atom transfer (HAT, or concerted PCET) mechanism and with electron poor phenols through a stepwise proton transfer/electron transfer (PT/ET) reaction mechanism. The analogous complexes [NiIII (Z)(L)] (Z=Cl, OCO2 H, O2 CCH3 , ONO2 ) reacted with all phenols through a HAT mechanism. We explore the reason for a change in mechanism with the highly basic fluoride ligand in 2. Complex 2 was also found to react one to two orders of magnitude faster than the corresponding analogous [NiIII (Z)(L)] complexes. This was ascribed to a high bond dissociation free energy value associated with H-F (135 kcal mol-1 ), which is postulated to be the product formed from PCET oxidation by 2 and is believed to be the driving force for the reaction. Our findings show that high-valent metal-fluoride complexes represent a class of highly reactive PCET oxidants.
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Affiliation(s)
- Prasenjit Mondal
- School of Chemistry, Trinity College Dublin, The University of Dublin, College Green, Dublin, 2, Ireland
| | - Aidan R McDonald
- School of Chemistry, Trinity College Dublin, The University of Dublin, College Green, Dublin, 2, Ireland
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27
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Mondal P, Lovisari M, Twamley B, McDonald AR. Fast Hydrocarbon Oxidation by a High‐Valent Nickel–Fluoride Complex. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202004639] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Prasenjit Mondal
- School of Chemistry Trinity College Dublin The University of Dublin College Green Dublin 2 Ireland
| | - Marta Lovisari
- School of Chemistry Trinity College Dublin The University of Dublin College Green Dublin 2 Ireland
| | - Brendan Twamley
- School of Chemistry Trinity College Dublin The University of Dublin College Green Dublin 2 Ireland
| | - Aidan R. McDonald
- School of Chemistry Trinity College Dublin The University of Dublin College Green Dublin 2 Ireland
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28
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Mondal P, Lovisari M, Twamley B, McDonald AR. Fast Hydrocarbon Oxidation by a High‐Valent Nickel–Fluoride Complex. Angew Chem Int Ed Engl 2020; 59:13044-13050. [DOI: 10.1002/anie.202004639] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Indexed: 11/11/2022]
Affiliation(s)
- Prasenjit Mondal
- School of Chemistry Trinity College Dublin The University of Dublin College Green Dublin 2 Ireland
| | - Marta Lovisari
- School of Chemistry Trinity College Dublin The University of Dublin College Green Dublin 2 Ireland
| | - Brendan Twamley
- School of Chemistry Trinity College Dublin The University of Dublin College Green Dublin 2 Ireland
| | - Aidan R. McDonald
- School of Chemistry Trinity College Dublin The University of Dublin College Green Dublin 2 Ireland
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29
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Fisher KJ, Feuer ML, Lant HMC, Mercado BQ, Crabtree RH, Brudvig GW. Concerted proton-electron transfer oxidation of phenols and hydrocarbons by a high-valent nickel complex. Chem Sci 2020; 11:1683-1690. [PMID: 32206289 PMCID: PMC7069233 DOI: 10.1039/c9sc05565g] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Accepted: 12/29/2019] [Indexed: 12/21/2022] Open
Abstract
The high-valent nickel(iii) complex Ni(pyalk)2 + (2) was prepared by oxidation of a nickel(ii) complex, Ni(pyalk)2 (1) (pyalk = 2-pyridyl-2-propanoate). 2 and derivatives were fully characterized by mass spectrometry and X-ray crystallography. Electron paramagnetic resonance spectroscopy and X-ray photoelectron spectroscopy confirm that the oxidation is metal-centered. 2 was found to react with a variety of phenolic and hydrocarbon substrates. A linear correlation between the measured rate constant and the substrate bond dissociation enthalpy (BDE) was found for both phenolic and hydrocarbon substrates. Large H/D kinetic isotope effects were also observed for both sets of substrates. These results suggest that 2 reacts through concerted proton-electron transfer (CPET). Analysis of measured thermodynamic parameters allows us to calculate a bond dissociation free energy (BDFE) of ∼91 kcal mol-1 for the O-H bond of the bound pyalk ligand. These findings may shed light onto CPET steps in oxidative catalysis and have implications for ligand design in catalytic systems.
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Affiliation(s)
- Katherine J Fisher
- Department of Chemistry , Yale University , New Haven , CT 06520 , USA . ;
| | - Margalit L Feuer
- Department of Chemistry , Yale University , New Haven , CT 06520 , USA . ;
| | - Hannah M C Lant
- Department of Chemistry , Yale University , New Haven , CT 06520 , USA . ;
| | - Brandon Q Mercado
- Department of Chemistry , Yale University , New Haven , CT 06520 , USA . ;
| | - Robert H Crabtree
- Department of Chemistry , Yale University , New Haven , CT 06520 , USA . ;
| | - Gary W Brudvig
- Department of Chemistry , Yale University , New Haven , CT 06520 , USA . ;
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30
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Lu X, Li XX, Lee YM, Jang Y, Seo MS, Hong S, Cho KB, Fukuzumi S, Nam W. Electron-Transfer and Redox Reactivity of High-Valent Iron Imido and Oxo Complexes with the Formal Oxidation States of Five and Six. J Am Chem Soc 2020; 142:3891-3904. [DOI: 10.1021/jacs.9b11682] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Xiaoyan Lu
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Xiao-Xi Li
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Yong-Min Lee
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Yuri Jang
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Mi Sook Seo
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Seungwoo Hong
- Department of Chemistry, Sookmyung Women’s University, Seoul 04310, Korea
| | - Kyung-Bin Cho
- Department of Chemistry, Jeonbuk National University, Jeonju 54896, Korea
| | - Shunichi Fukuzumi
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
- Graduate School of Science and Engineering, Meijo University, Nagoya, Aichi 468-8502, Japan
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, China
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31
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Ding CW, Luo W, Zhou JY, Ma XJ, Chen GH, Zhou XP, Li D. Hydroxo Iron(III) Sites in a Metal-Organic Framework: Proton-Coupled Electron Transfer and Catalytic Oxidation of Alcohol with Molecular Oxygen. ACS APPLIED MATERIALS & INTERFACES 2019; 11:45621-45628. [PMID: 31724842 DOI: 10.1021/acsami.9b15311] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Metalloenzymes are powerful biocatalysts that can catalyze particular chemical reactions with high activity, selectivity, and specificity under mild conditions. Metal-organic frameworks (MOFs) composed of metal ions or metal clusters and organic ligands with defined cavities have the potential to impart enzyme-like catalytic activity and mimic metalloenzymes. Here, a new metal-organic framework implanted with hydroxo iron(III) sites with the structural and reactivity characteristics of iron-containing lipoxygenases is reported. Similar to lipoxygenases, the hydrogen atoms and electrons of the substrate can transfer to the hydroxo iron(III) sites, showing typical proton-coupled electron transfer behavior. In the reactivity mimicking biology system, similar to alcohol oxidase, the material also catalyses the oxidation of alcohol into aldehyde by using O2 with a high yield and 100% selectivity under mild conditions, without the use of a radical cocatalyst or photoexcitation. These results provide strong evidence for the high structural fidelity of enzymatically active sites in MOF materials, verifying that MOFs provide an ideal platform for designing biomimetic heterogeneous catalysts with high conversion efficiency and product selectivity.
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Affiliation(s)
- Chong-Wei Ding
- College of Chemistry and Materials Science , Jinan University , Guangzhou , Guangdong 510632 , P. R. China
- Department of Chemistry , Shantou University , Shantou , Guangdong 515063 , P. R. China
| | - Wenzhi Luo
- Department of Chemistry , Shantou University , Shantou , Guangdong 515063 , P. R. China
| | - Jie-Yi Zhou
- College of Chemistry and Materials Science , Jinan University , Guangzhou , Guangdong 510632 , P. R. China
- Department of Chemistry , Shantou University , Shantou , Guangdong 515063 , P. R. China
| | - Xin-Jie Ma
- Department of Chemistry , Shantou University , Shantou , Guangdong 515063 , P. R. China
| | - Guang-Hui Chen
- Department of Chemistry , Shantou University , Shantou , Guangdong 515063 , P. R. China
| | - Xiao-Ping Zhou
- College of Chemistry and Materials Science , Jinan University , Guangzhou , Guangdong 510632 , P. R. China
| | - Dan Li
- College of Chemistry and Materials Science , Jinan University , Guangzhou , Guangdong 510632 , P. R. China
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32
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Unjaroen D, Gericke R, Lovisari M, Nelis D, Mondal P, Pirovano P, Twamley B, Farquhar ER, McDonald AR. High-Valent d 7 Ni III versus d 8 Cu III Oxidants in PCET. Inorg Chem 2019; 58:16838-16848. [PMID: 31804808 DOI: 10.1021/acs.inorgchem.9b03101] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Oxygenases have been postulated to utilize d4 FeIV and d8 CuIII oxidants in proton-coupled electron transfer (PCET) hydrocarbon oxidation. In order to explore the influence the metal ion and d-electron count can hold over the PCET reactivity, two metastable high-valent metal-oxygen adducts, [NiIII(OAc)(L)] (1b) and [CuIII(OAc)(L)] (2b), L = N,N'-(2,6-diisopropylphenyl)-2,6-pyridinedicarboxamidate, were prepared from their low-valent precursors [NiII(OAc)(L)]- (1a) and [CuII(OAc)(L)]- (2a). The complexes 1a/b-2a/b were characterized using nuclear magnetic resonance, Fourier transform infrared, electron paramagnetic resonance, X-ray diffraction, and absorption spectroscopies and mass spectrometry. Both complexes were capable of activating substrates through a concerted PCET mechanism (hydrogen atom transfer, HAT, or concerted proton and electron transfer, CPET). The reactivity of 1b and 2b toward a series of para-substituted 2,6-di-tert-butylphenols (p-X-2,6-DTBP; X = OCH3, C(CH3)3, CH3, H, Br, CN, NO2) was studied, showing similar rates of reaction for both complexes. In the oxidation of xanthene, the d8 CuIII oxidant displayed a small increase in the rate constant compared to that of the d7 NiIII oxidant. The d8 CuIII oxidant was capable of oxidizing a large family of hydrocarbon substrates with bond dissociation enthalpy (BDEC-H) values up to 90 kcal/mol. It was previously observed that exchanging the ancillary anionic donor ligand in such complexes resulted in a 20-fold enhancement in the rate constant, an observation that is further enforced by comparison of 1b and 2b to the literature precedents. In contrast, we observed only minor differences in the rate constants upon comparing 1b to 2b. It was thus concluded that in this case the metal ion has a minor impact, while the ancillary donor ligand yields more kinetic control over HAT/CPET oxidation.
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Affiliation(s)
- Duenpen Unjaroen
- School of Chemistry, Trinity College Dublin , The University of Dublin , College Green , Dublin 2 , Ireland
| | - Robert Gericke
- School of Chemistry, Trinity College Dublin , The University of Dublin , College Green , Dublin 2 , Ireland
| | - Marta Lovisari
- School of Chemistry, Trinity College Dublin , The University of Dublin , College Green , Dublin 2 , Ireland
| | - Daniel Nelis
- School of Chemistry, Trinity College Dublin , The University of Dublin , College Green , Dublin 2 , Ireland
| | - Prasenjit Mondal
- School of Chemistry, Trinity College Dublin , The University of Dublin , College Green , Dublin 2 , Ireland
| | - Paolo Pirovano
- School of Chemistry, Trinity College Dublin , The University of Dublin , College Green , Dublin 2 , Ireland
| | - Brendan Twamley
- School of Chemistry, Trinity College Dublin , The University of Dublin , College Green , Dublin 2 , Ireland
| | - Erik R Farquhar
- Case Western Reserve University Center for Synchrotron Biosciences, National Synchrotron Light Source II , Brookhaven National Laboratory II , Upton , New York 11973 , United States
| | - Aidan R McDonald
- School of Chemistry, Trinity College Dublin , The University of Dublin , College Green , Dublin 2 , Ireland
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33
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Ehudin MA, Quist DA, Karlin KD. Enhanced Rates of C-H Bond Cleavage by a Hydrogen-Bonded Synthetic Heme High-Valent Iron(IV) Oxo Complex. J Am Chem Soc 2019; 141:12558-12569. [PMID: 31318198 PMCID: PMC6734939 DOI: 10.1021/jacs.9b01253] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Secondary coordination sphere interactions are critical in facilitating the formation, stabilization, and enhanced reactivity of high-valent oxidants required for essential biochemical processes. Herein, we compare the C-H bond oxidizing capabilities of spectroscopically characterized synthetic heme iron(IV) oxo complexes, F8Cmpd-II (F8 = tetrakis(2,6-difluorophenyl)porphyrinate), and a 2,6-lutidinium triflate (LutH+) Lewis acid adduct involving ferryl O-atom hydrogen-bonding, F8Cmpd-II(LutH+). Second-order rate constants utilizing C-H and C-D substrates were obtained by UV-vis spectroscopic monitoring, while products were characterized and quantified by EPR spectroscopy and gas chromatography (GC). With xanthene, F8Cmpd-II(LutH+) reacts 40 times faster (k2 = 14.2 M-1 s-1; -90 °C) than does F8Cmpd-II, giving bixanthene plus xanthone and the heme product [F8FeIIIOH2]+. For substrates with greater C-H bond dissociation energies (BDEs) F8Cmpd-II(LutH+) reacts with the second order rate constants k2(9,10-dihydroanthracene; DHA) = 0.485 M-1 s-1 and k2(fluorene) = 0.102 M-1 s-1 (-90 °C); by contrast, F8Cmpd-II is unreactive toward these substrates. For xanthene vs xanthene-(d2), large, nonclassical deuterium kinetic isotope effects are roughly estimated for both F8Cmpd-II and F8Cmpd-II(LutH+). The deuterated H-bonded analog, F8Cmpd-II(LutD+), was also prepared; for the reaction with DHA, an inverse KIE (compared to F8Cmpd-II(LutH+)) was observed. This work originates/inaugurates experimental investigation of the reactivity of authentic H-bonded heme-based FeIV═O compounds, critically establishing the importance of oxo H-bonding (or protonation) in heme complexes and enzyme active sites.
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Affiliation(s)
- Melanie A. Ehudin
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - David A. Quist
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Kenneth D. Karlin
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, United States
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Koike T, Kosai T, Iwamoto T. 1,4‐Dehydrogenation with a Two‐Coordinate Cyclic (Alkyl)(amino)silylene. Chemistry 2019; 25:9295-9302. [DOI: 10.1002/chem.201901407] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 04/26/2019] [Indexed: 11/10/2022]
Affiliation(s)
- Taichi Koike
- Department of ChemistryGraduate School of ScienceTohoku University Aoba-ku Sendai 980-8578 Japan
| | - Tomoyuki Kosai
- Department of ChemistryGraduate School of ScienceTohoku University Aoba-ku Sendai 980-8578 Japan
| | - Takeaki Iwamoto
- Department of ChemistryGraduate School of ScienceTohoku University Aoba-ku Sendai 980-8578 Japan
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35
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Matheu R, Ertem MZ, Gimbert-Suriñach C, Sala X, Llobet A. Seven Coordinated Molecular Ruthenium–Water Oxidation Catalysts: A Coordination Chemistry Journey. Chem Rev 2019; 119:3453-3471. [DOI: 10.1021/acs.chemrev.8b00537] [Citation(s) in RCA: 107] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Roc Matheu
- Institute of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science and Technology (BIST), Avinguda Països Catalans 16, 43007 Tarragona, Spain
- Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, Marcel·lí Domingo s/n, 43007 Tarragona, Spain
| | - Mehmed Z. Ertem
- Chemistry Division, Energy & Photon Sciences Directorate, Brookhaven National Laboratory, Upton, New York 11973-5000, United States
| | - Carolina Gimbert-Suriñach
- Institute of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science and Technology (BIST), Avinguda Països Catalans 16, 43007 Tarragona, Spain
| | - Xavier Sala
- Departament de Química, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain
| | - Antoni Llobet
- Institute of Chemical Research of Catalonia (ICIQ), Barcelona Institute of Science and Technology (BIST), Avinguda Països Catalans 16, 43007 Tarragona, Spain
- Departament de Química, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain
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36
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Goetz MK, Anderson JS. Experimental Evidence for p K a-Driven Asynchronicity in C-H Activation by a Terminal Co(III)-Oxo Complex. J Am Chem Soc 2019; 141:4051-4062. [PMID: 30739450 DOI: 10.1021/jacs.8b13490] [Citation(s) in RCA: 84] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
C-H activation by transition metal oxo complexes is a fundamental reaction in oxidative chemistry carried out by both biological and synthetic systems. This centrality has motivated efforts to understand the patterns and mechanisms of such reactivity. We have therefore thoroughly examined the C-H activation reactivity of the recently synthesized and characterized late transition metal oxo complex PhB ( tBuIm)3CoIIIO. Precise values for the p Ka and BDFEO-H of the conjugates of this complex have been experimentally determined and provide insight into the observed reactivity. The activation parameters for the reaction between this complex and 9,10-dihydroanthracene have also been measured and compared to previous literature examples. Evaluation of the rates of reaction of PhB( tBuIm)3CoIIIO with a variety of hydrogen atom donors demonstrates that the reactivity of this complex is dependent on the p Ka of the substrate of interest rather than the BDEC-H. This observation runs counter to the commonly cited reactivity paradigm for many other transition metal oxo complexes. Experimental and computational analysis of C-H activation reactions by PhB( tBuIm)3CoIIIO reveals that the transition state for these processes contains significant proton transfer character. Nevertheless, additional experiments strongly suggest that the reaction does not occur via a stepwise process, leading to the conclusion that C-H activation by this CoIII-oxo complex proceeds by a p Ka-driven "asynchronous" concerted mechanism. This result supports a new pattern of reactivity that may be applicable to other systems and could result in alternative selectivity for C-H activation reactions mediated by transition metal oxo complexes.
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Affiliation(s)
- McKenna K Goetz
- Department of Chemistry , University of Chicago , Chicago , Illinois 60637 , United States
| | - John S Anderson
- Department of Chemistry , University of Chicago , Chicago , Illinois 60637 , United States
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37
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Chang MC, Jesse KA, Filatov AS, Anderson JS. Reversible homolytic activation of water via metal-ligand cooperativity in a T-shaped Ni(ii) complex. Chem Sci 2019; 10:1360-1367. [PMID: 30809351 PMCID: PMC6354739 DOI: 10.1039/c8sc03719a] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 11/05/2018] [Indexed: 12/18/2022] Open
Abstract
A T-shaped Ni(ii) complex [Tol,PhDHPy]Ni has been prepared and characterized. EPR spectra and DFT calculations of this complex suggest that the electronic structure is best described as a high-spin Ni(ii) center antiferromagnetically coupled with a ligand-based radical. This complex reacts with water at room temperature to generate the dimeric complex [Tol,PhDHPy]Ni(μ-OH)Ni[Tol,PhDHPyH] which has been thoroughly characterized by SXRD, NMR, IR and deuterium-labeling experiments. Addition of simple ligands such as phosphines or pyridine displaces water and demonstrates the reversibility of water activation in this system. The water activation step has been examined by kinetic studies and DFT calculations which suggest an unusual homolytic reaction via a bimetallic mechanism. The ΔH ‡, ΔS ‡ and KIE (k H/k D) of the reaction are 5.5 kcal mol-1, -23.8 cal mol-1 K-1, and 2.4(1), respectively. In addition to the reversibility of water addition, this system is capable of activating water towards net O-atom transfer to substrates such as aromatic C-H bonds and phosphines. This reactivity is facilitated by the ability of the dihydrazonopyrrole ligand to accept H-atoms and illustrates the utility of metal ligand cooperation in activating O-H bonds with high bond dissociation energies.
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Affiliation(s)
- Mu-Chieh Chang
- Department of Chemistry , The University of Chicago , Chicago , Illinois 60637 , USA .
| | - Kate A Jesse
- Department of Chemistry , The University of Chicago , Chicago , Illinois 60637 , USA .
| | - Alexander S Filatov
- Department of Chemistry , The University of Chicago , Chicago , Illinois 60637 , USA .
| | - John S Anderson
- Department of Chemistry , The University of Chicago , Chicago , Illinois 60637 , USA .
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38
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Sankaralingam M, Lee YM, Pineda-Galvan Y, Karmalkar DG, Seo MS, Jeon SH, Pushkar Y, Fukuzumi S, Nam W. Redox Reactivity of a Mononuclear Manganese-Oxo Complex Binding Calcium Ion and Other Redox-Inactive Metal Ions. J Am Chem Soc 2019; 141:1324-1336. [PMID: 30580510 DOI: 10.1021/jacs.8b11492] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Mononuclear nonheme manganese(IV)-oxo complexes binding calcium ion and other redox-inactive metal ions, [(dpaq)MnIV(O)]+-M n+ (1-Mn+, M n+ = Ca2+, Mg2+, Zn2+, Lu3+, Y3+, Al3+, and Sc3+) (dpaq = 2-[bis(pyridin-2-ylmethyl)]amino- N-quinolin-8-yl-acetamidate), were synthesized by reacting a hydroxomanganese(III) complex, [(dpaq)MnIII(OH)]+, with iodosylbenzene (PhIO) in the presence of redox-inactive metal ions (M n+). The Mn(IV)-oxo complexes were characterized using various spectroscopic techniques. In reactivity studies, we observed contrasting effects of M n+ on the reactivity of 1-M n+ in redox reactions such as electron-transfer (ET), oxygen atom transfer (OAT), and hydrogen atom transfer (HAT) reactions. In the OAT and ET reactions, the reactivity order of 1-M n+, such as 1-Sc3+ ≈ 1-Al3+ > 1-Y3+ > 1-Lu3+ > 1-Zn2+ > 1-Mg2+ > 1-Ca2+, follows the Lewis acidity of M n+ bound to the Mn-O moiety; that is, the stronger the Lewis acidity of M n+, the higher the reactivity of 1-M n+ becomes. In sharp contrast, the reactivity of 1-M n+ in the HAT reaction was reversed, giving the reactivity order 1-Ca2+ > 1-Mg2+ > 1-Zn2+ > 1-Lu3+> 1-Y3+> 1-Al3+ ≈ 1-Sc3+; that is, the higher is Lewis acidity of M n+, the lower the reactivity of 1-M n+ in the HAT reaction. The latter result implies that the Lewis acidity of M n+ bound to the Mn-O moiety can modulate the basicity of the metal-oxo moiety, thus influencing the HAT reactivity of 1-M n+; cytochrome P450 utilizes the axial thiolate ligand to increase the basicity of the iron-oxo moiety, which enhances the reactivity of compound I in C-H bond activation reactions.
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Affiliation(s)
| | - Yong-Min Lee
- Department of Chemistry and Nano Science , Ewha Womans University , Seoul 03760 , Korea
| | - Yuliana Pineda-Galvan
- Department of Physics and Astronomy , Purdue University , 525 Northwestern Avenue , West Lafayette , Indiana 47907 , United States
| | - Deepika G Karmalkar
- Department of Chemistry and Nano Science , Ewha Womans University , Seoul 03760 , Korea
| | - Mi Sook Seo
- Department of Chemistry and Nano Science , Ewha Womans University , Seoul 03760 , Korea
| | - So Hyun Jeon
- Department of Chemistry and Nano Science , Ewha Womans University , Seoul 03760 , Korea
| | - Yulia Pushkar
- Department of Physics and Astronomy , Purdue University , 525 Northwestern Avenue , West Lafayette , Indiana 47907 , United States
| | - Shunichi Fukuzumi
- Department of Chemistry and Nano Science , Ewha Womans University , Seoul 03760 , Korea.,Faculty of Science and Engineering, SENTAN, Japan Science and Technology Agency (JST) , Meijo University , Nagoya , Aichi 468-8502 , Japan
| | - Wonwoo Nam
- Department of Chemistry and Nano Science , Ewha Womans University , Seoul 03760 , Korea.,State Key Laboratory for Oxo Synthesis and Selective Oxidation, Center for Excellence in Molecular Synthesis, Suzhou Research Institute of LICP, Lanzhou Institute of Chemical Physics (LICP) , Chinese Academy of Sciences , Lanzhou , 730000 , China
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Resa S, Millán A, Fuentes N, Crovetto L, Luisa Marcos M, Lezama L, Choquesillo-Lazarte D, Blanco V, Campaña AG, Cárdenas DJ, Cuerva JM. O–H and (CO)N–H bond weakening by coordination to Fe(ii). Dalton Trans 2019; 48:2179-2189. [DOI: 10.1039/c8dt04689a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Coordination of hydroxyl/amide groups to Fe(ii) diminishes BDFEs of O–H and (CO)N–H bonds down to 76.0 and 80.5 kcal mol−1 respectively.
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40
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Sankaralingam M, Lee YM, Karmalkar DG, Nam W, Fukuzumi S. A Mononuclear Non-heme Manganese(III)–Aqua Complex as a New Active Oxidant in Hydrogen Atom Transfer Reactions. J Am Chem Soc 2018; 140:12695-12699. [DOI: 10.1021/jacs.8b07772] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
| | - Yong-Min Lee
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Deepika G. Karmalkar
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Shunichi Fukuzumi
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
- Faculty of Science and Engineering, Meijo University, Nagoya, Aichi 468-8502, Japan
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41
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Massie AA, Sinha A, Parham JD, Nordlander E, Jackson TA. Relationship between Hydrogen-Atom Transfer Driving Force and Reaction Rates for an Oxomanganese(IV) Adduct. Inorg Chem 2018; 57:8253-8263. [PMID: 29974738 DOI: 10.1021/acs.inorgchem.8b00852] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Hydrogen atom transfer (HAT) reactions by high-valent metal-oxo intermediates are important in both biological and synthetic systems. While the HAT reactivity of FeIV-oxo adducts has been extensively investigated, studies of analogous MnIV-oxo systems are less common. There are several recent reports of MnIV-oxo complexes, supported by neutral pentadentate ligands, capable of cleaving strong C-H bonds at rates approaching those of analogous FeIV-oxo species. In this study, we provide a thorough analysis of the HAT reactivity of one of these MnIV-oxo complexes, [MnIV(O)(2pyN2Q)]2+, which is supported by an N5 ligand with equatorial pyridine and quinoline donors. This complex is able to oxidize the strong C-H bonds of cyclohexane with rates exceeding those of FeIV-oxo complexes with similar ligands. In the presence of excess oxidant (iodosobenzene), cyclohexane oxidation by [MnIV(O)(2pyN2Q)]2+ is catalytic, albeit with modest turnover numbers. Because the rate of cyclohexane oxidation by [MnIV(O)(2pyN2Q)]2+ was faster than that predicted by a previously published Bells-Evans-Polanyi correlation, we expanded the scope of this relationship by determining HAT reaction rates for substrates with bond dissociation energies spanning 20 kcal/mol. This extensive analysis showed the expected correlation between reaction rate and the strength of the substrate C-H bond, albeit with a shallow slope. The implications of this result with regard to MnIV-oxo and FeIV-oxo reactivity are discussed.
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Affiliation(s)
- Allyssa A Massie
- The University of Kansas , Chemistry Department , 1251 Wescoe Hall Drive , Lawrence , Kansas 66045 , United States
| | - Arup Sinha
- Lund University , Chemical Physics, Department of Chemistry , Box 124, SE-221 00 Lund , Sweden
| | - Joshua D Parham
- The University of Kansas , Chemistry Department , 1251 Wescoe Hall Drive , Lawrence , Kansas 66045 , United States
| | - Ebbe Nordlander
- Lund University , Chemical Physics, Department of Chemistry , Box 124, SE-221 00 Lund , Sweden
| | - Timothy A Jackson
- The University of Kansas , Chemistry Department , 1251 Wescoe Hall Drive , Lawrence , Kansas 66045 , United States
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42
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Hill EA, Kelty ML, Filatov AS, Anderson JS. Isolable iodosylarene and iodoxyarene adducts of Co and their O-atom transfer and C-H activation reactivity. Chem Sci 2018; 9:4493-4499. [PMID: 29896391 PMCID: PMC5958341 DOI: 10.1039/c8sc01167b] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 04/19/2018] [Indexed: 01/04/2023] Open
Abstract
We report an unusual series of discrete iodosyl- and iodoxyarene adducts of Co(ii) including detailed studies of their O-transfer reactivity and mechanism.
We report an unusual series of discrete iodosyl- and iodoxyarene adducts of Co. The formation of these adducts was confirmed by a suite of techniques including single crystal X-ray diffraction. The reactivity of these adducts with O-atom acceptors and an H-atom donor has been investigated with particular focus on elucidating mechanistic details. Detailed kinetic analysis allows for discrimination between proposed oxo and adduct mediated mechanisms. In particular, these reactions have been interrogated by competition experiments with isotopically labelled mixtures which shows that all of the studied adducts display a large KIE. These studies suggest different mechanisms may be relevant depending on subtle substituent changes in the adduct complexes. Reactivity data are consistent with the involvement of a transient oxo complex in one case, while the two other systems appear to react with substrates directly as iodosyl- or iodoxyarene adducts. These results support that reactivity typically ascribed to metal-oxo complexes, such as O-atom transfer and C–H activation, can also be mediated by discrete transition metal iodosyl- or iodoxyarene adducts that are frequent intermediates in the generation of oxo complexes. The influence of additional Lewis acids such as Sc3+ on the reactivity of these systems has also been investigated.
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Affiliation(s)
- Ethan A Hill
- Department of Chemistry , The University of Chicago , 5735 S. Ellis Ave , Chicago , IL 60637 , USA .
| | - Margaret L Kelty
- Department of Chemistry , The University of Chicago , 5735 S. Ellis Ave , Chicago , IL 60637 , USA .
| | - Alexander S Filatov
- Department of Chemistry , The University of Chicago , 5735 S. Ellis Ave , Chicago , IL 60637 , USA .
| | - John S Anderson
- Department of Chemistry , The University of Chicago , 5735 S. Ellis Ave , Chicago , IL 60637 , USA .
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Mondal P, Pirovano P, Das A, Farquhar ER, McDonald AR. Hydrogen Atom Transfer by a High-Valent Nickel-Chloride Complex. J Am Chem Soc 2018; 140:1834-1841. [DOI: 10.1021/jacs.7b11953] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Prasenjit Mondal
- School
of Chemistry and CRANN/AMBER Nanoscience Institute, Trinity College Dublin, The University of Dublin, College Green, Dublin 2, Ireland
| | - Paolo Pirovano
- School
of Chemistry and CRANN/AMBER Nanoscience Institute, Trinity College Dublin, The University of Dublin, College Green, Dublin 2, Ireland
| | - Ankita Das
- School
of Chemistry and CRANN/AMBER Nanoscience Institute, Trinity College Dublin, The University of Dublin, College Green, Dublin 2, Ireland
| | - Erik R. Farquhar
- Case
Western Reserve University Center for Synchrotron Biosciences, National Synchrotron Light Source II, Brookhaven National Laboratory II, Upton, New York 11973, United States
| | - Aidan R. McDonald
- School
of Chemistry and CRANN/AMBER Nanoscience Institute, Trinity College Dublin, The University of Dublin, College Green, Dublin 2, Ireland
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Affiliation(s)
- Paolo Pirovano
- School of Chemistry and CRANN/AMBER Nanoscience Institute; Trinity College Dublin; The University of Dublin; College Green 2 Dublin Ireland
| | - Aidan R. McDonald
- School of Chemistry and CRANN/AMBER Nanoscience Institute; Trinity College Dublin; The University of Dublin; College Green 2 Dublin Ireland
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45
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Ching WM, Zhou A, Klein JEMN, Fan R, Knizia G, Cramer CJ, Guo Y, Que L. Characterization of the Fleeting Hydroxoiron(III) Complex of the Pentadentate TMC-py Ligand. Inorg Chem 2017; 56:11129-11140. [DOI: 10.1021/acs.inorgchem.7b01459] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | | | - Ruixi Fan
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Gerald Knizia
- Department
of Chemistry, Pennsylvania State University, 401A Chemistry Bldg; University Park, Pennsylvania 16802, United States
| | | | - Yisong Guo
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
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46
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Nurdin L, Spasyuk DM, Piers WE, Maron L. Reactions of Neutral Cobalt(II) Complexes of a Dianionic Tetrapodal Pentadentate Ligand: Cobalt(III) Amides from Imido Radicals. Inorg Chem 2017; 56:4157-4168. [DOI: 10.1021/acs.inorgchem.7b00174] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Lucie Nurdin
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada T2N 1N4
| | - Denis M. Spasyuk
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada T2N 1N4
- Canadian Light Source Inc., 44 Innovation Boulevard, Saskatoon, Saskatchewan, Canada S7N 2V3
| | - Warren E. Piers
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta, Canada T2N 1N4
| | - Laurent Maron
- LPCNO, Université de Toulouse, INSA, UPS, LPCNO, 135
Avenue de Rangueil, and CNRS, LPCNO, F-31077 Toulouse, France
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47
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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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48
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Gao H, Groves JT. Fast Hydrogen Atom Abstraction by a Hydroxo Iron(III) Porphyrazine. J Am Chem Soc 2017; 139:3938-3941. [PMID: 28245648 DOI: 10.1021/jacs.6b13091] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
A reactive hydroxoferric porphyrazine complex, [(PyPz)FeIII(OH) (OH2)]4+ (1, PyPz = tetramethyl-2,3-pyridino porphyrazine), has been prepared via one-electron oxidation of the corresponding ferrous species [(PyPz)FeII(OH2)2]4+ (2). Electrochemical analysis revealed a pH-dependent and remarkably high FeIII-OH/FeII-OH2 reduction potential of 680 mV vs Ag/AgCl at pH 5.2. Nernstian behavior from pH 2 to pH 8 indicates a one-proton, one-electron interconversion throughout that range. The O-H bond dissociation energy of the FeII-OH2 complex was estimated to be 84 kcal mol-1. Accordingly, 1 reacts rapidly with a panel of substrates via C-H hydrogen atom transfer (HAT), reducing 1 to [(PyPz)FeII(OH2)2]4+ (2). The second-order rate constant for the reaction of [(PyPz)FeIII(OH) (OH2)]4+ with xanthene was 2.22 × 103 M-1 s-1, 5-6 orders of magnitude faster than other reported FeIII-OH complexes and faster than many ferryl complexes.
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Affiliation(s)
- Hongxin Gao
- Department of Chemistry, Princeton University , Princeton, New Jersey 08544, United States
| | - John T Groves
- Department of Chemistry, Princeton University , Princeton, New Jersey 08544, United States
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Chen L, Khadivi A, Singh M, Jurss JW. Synthesis of a pentadentate, polypyrazine ligand and its application in cobalt-catalyzed hydrogen production. Inorg Chem Front 2017. [DOI: 10.1039/c7qi00362e] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A molecular cobalt complex bearing an unprecedented pentadentate, polypyrazine ligand is reported for electrocatalytic H2 evolution from pH 7 water.
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Affiliation(s)
- Lizhu Chen
- Department of Chemistry and Biochemistry
- University of Mississippi
- University
- USA
| | - Amir Khadivi
- Department of Chemistry and Biochemistry
- University of Mississippi
- University
- USA
| | - Manpreet Singh
- Department of Chemistry and Biochemistry
- University of Mississippi
- University
- USA
| | - Jonah W. Jurss
- Department of Chemistry and Biochemistry
- University of Mississippi
- University
- USA
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50
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Corona T, Padamati SK, Acuña-Parés F, Duboc C, Browne WR, Company A. Trapping of superoxido cobalt and peroxido dicobalt species formed reversibly from CoII and O2. Chem Commun (Camb) 2017; 53:11782-11785. [DOI: 10.1039/c7cc05904c] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Superoxido cobalt(iii) and peroxido dicobalt(iii) species are formed in the temperature dependent reversible reaction of a common cobalt(ii) precursor with O2.
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Affiliation(s)
- Teresa Corona
- Grup de Química Bioinspirada
- Supramolecular i Catàlisi (QBIS-CAT)
- Institut de Química Computacional i Catàlisi (IQCC)
- Departament de Química
- Universitat de Girona
| | - Sandeep K. Padamati
- Molecular Inorganic Chemistry
- Stratingh Institute for Chemistry
- Faculty of Science and Engineering
- University of Groningen
- Nijenborgh 4
| | - Ferran Acuña-Parés
- Institut Català d’Investigació Química (ICIQ)
- Av. Països Catalans 16
- E-43007 Tarragona
- Spain
| | - Carole Duboc
- Univ. Grenoble Alpes
- UMR CNRS 5250
- Département de Chimie Moléculaire
- F-38000 Grenoble
- France
| | - Wesley R. Browne
- Molecular Inorganic Chemistry
- Stratingh Institute for Chemistry
- Faculty of Science and Engineering
- University of Groningen
- Nijenborgh 4
| | - Anna Company
- Grup de Química Bioinspirada
- Supramolecular i Catàlisi (QBIS-CAT)
- Institut de Química Computacional i Catàlisi (IQCC)
- Departament de Química
- Universitat de Girona
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