1
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Rice DB, Wong D, Weyhermüller T, Neese F, DeBeer S. The spin-forbidden transition in iron(IV)-oxo catalysts relevant to two-state reactivity. SCIENCE ADVANCES 2024; 10:eado1603. [PMID: 38941457 PMCID: PMC11212722 DOI: 10.1126/sciadv.ado1603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 05/23/2024] [Indexed: 06/30/2024]
Abstract
Quintet oxoiron(IV) intermediates are often invoked in nonheme iron enzymes capable of performing selective oxidation, while most well-characterized synthetic model oxoiron(IV) complexes have a triplet ground state. These differing spin states lead to the proposal of a two-state reactivity model, where the complexes cross from the triplet to an excited quintet state. However, the energy of this quintet state has never been measured experimentally. Here, magnetic circular dichroism is used to assign the singlet and triplet excited states in a series of triplet oxoiron(IV) complexes. These transition energies are used to determine the energies of the quintet state via constrained fitting of 2p3d resonant inelastic x-ray scattering. This allowed for a direct correlation between the quintet energies and substrate C─H oxidation rates.
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Affiliation(s)
- Derek B. Rice
- Max Planck Institute for Chemical Energy Conversion, D-45470 Mülheim an der Ruhr, Germany
| | - Deniz Wong
- Helmholtz-Zentrum Berlin für Materialien und Energie, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany
| | - Thomas Weyhermüller
- Max Planck Institute for Chemical Energy Conversion, D-45470 Mülheim an der Ruhr, Germany
| | - Frank Neese
- Max-Planck-Institut für Kohlenforschung, D-45470 Mülheim an der Ruhr, Germany
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion, D-45470 Mülheim an der Ruhr, Germany
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2
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Munda M, Chatterjee D, Majhi M, Biswas S, Pal D, Bisai A. Total synthesis of naturally occurring abietane diterpenoids via a late-stage Fe(iii)- bTAML catalysed Csp 3-H functionalization. RSC Adv 2024; 14:20420-20424. [PMID: 38932981 PMCID: PMC11200212 DOI: 10.1039/d4ra03791j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Accepted: 06/13/2024] [Indexed: 06/28/2024] Open
Abstract
The synthesis of diverse trans-fused decalins, including the abietane diterpenoids scaffold, using an efficient selective oxidation strategy is described. The abietane core was demonstrated to be a versatile scaffold that can be site-selectively functionalized. The utility of this novel oxidation strategy was showcased in a concise total synthesis of six abietane congeners.
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Affiliation(s)
- Mintu Munda
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal Bhauri Bhopal-462 066 Madhya Pradesh India
| | - Debasmita Chatterjee
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata Mohanpur Nadia-741 246 West Bengal India
| | - Moumita Majhi
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata Mohanpur Nadia-741 246 West Bengal India
| | - Souvik Biswas
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata Mohanpur Nadia-741 246 West Bengal India
| | - Debopam Pal
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata Mohanpur Nadia-741 246 West Bengal India
| | - Alakesh Bisai
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal Bhauri Bhopal-462 066 Madhya Pradesh India
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata Mohanpur Nadia-741 246 West Bengal India
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3
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Sen A, Britto NJ, Kass D, Ray K, Rajaraman G. Origin of Unprecedented Formation and Reactivity of Fe IV═O Species via Oxygen Activation: Role of Noncovalent Interactions and Magnetic Coupling. Inorg Chem 2024; 63:9809-9822. [PMID: 38739843 DOI: 10.1021/acs.inorgchem.4c00371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Emulating the capabilities of the soluble methane monooxygenase (sMMO) enzymes, which effortlessly activate oxygen at diiron(II) centers to form a reactive diiron(IV) intermediate Q, which then performs the challenging oxidation of methane to methanol, poses a significant challenge. Very recently, one of us reported the mononuclear complex [(cyclam)FeII(CH3CN)2]2+ (1), which performed a rare bimolecular activation of the molecule of O2 to generate two molecules of FeIV═O without the requirement of external proton or electron sources, similar to sMMO. In the present study, we employed the density functional theory (DFT) calculations to investigate this unique mechanism of O2 activation. We show that secondary hydrogen-bonding interactions between ligand N-H groups and O2 play a vital role in reducing the energy barrier associated with the initial O2 binding at 1 and O-O bond cleavage to form the FeIV═O complex. Further, the unique reactivity of FeIV═O species toward simultaneous C-H and O-H bond activation process has been demonstrated. Our study unveils that the nature of the magnetic coupling between the diiron centers is also crucial. Given that the influence of magnetic coupling and noncovalent interactions in catalysis remains largely unexplored, this unexplored realm presents numerous avenues for experimental chemists to develop novel structural and functional analogues of sMMO.
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Affiliation(s)
- Asmita Sen
- Department of Chemistry, IIT Bombay, Powai, Mumbai-400076, India
| | | | - Dustin Kass
- Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
| | - Kallol Ray
- Institut für Chemie, Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489 Berlin, Germany
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4
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Fagnano A, Frateloreto F, Paoloni R, Sappino C, Lanzalunga O, Costas M, Di Stefano S, Olivo G. Proximity Effects on the Reactivity of a Nonheme Iron (IV) Oxo Complex in C-H Oxidation. Angew Chem Int Ed Engl 2024; 63:e202401694. [PMID: 38478739 DOI: 10.1002/anie.202401694] [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: 01/24/2024] [Indexed: 04/05/2024]
Abstract
Precise control of substrate positioning and orientation (its proximity to the reactive unit) is often invoked to rationalize the superior enzymatic reaction rates and selectivities when compared to synthetic models. Artificial nonheme iron (IV) oxo (Fe(IV)=O) complexes react with C(sp3)-H bonds via a biomimetic Hydrogen Atom Transfer/Hydroxyl Rebound mechanism, but rates, site-selectivity and even hydroxyl rebound efficiency (ligand rebound versus substrate radical diffusion) are smaller than in oxygenases. Herein, we quantitatively analyze how substrate binding modulates nonheme Fe(IV)=O reactivity by comparing rates and outcomes of C-H oxidation by a pair of Fe(IV)=O complexes that share the same first coordination sphere but only one contains a crown ether receptor that recognizes the substrate. Substrate binding makes the reaction intramolecular, exhibiting Michaelis-Menten kinetics and increased reaction rates. In addition, C-H oxidation occurs with high site selectivity for remote sites. Analysis of Effective Molarity reveals that the system operates at its maximal theoretical capability for the oxidation of these remote sites. Remarkably, substrate positioning also affects Hydroxyl Rebound, whose efficiency only increases on the sites placed in proximity by recognition. Overall, these observations provide evidence that supramolecular control of substrate positioning can effectively modulate the reactivity of oxygenases and its models.
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Affiliation(s)
- Alessandro Fagnano
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro, 5 I-00185, Rome, Italy
| | - Federico Frateloreto
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro, 5 I-00185, Rome, Italy
| | - Roberta Paoloni
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro, 5 I-00185, Rome, Italy
| | - Carla Sappino
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro, 5 I-00185, Rome, Italy
| | - Osvaldo Lanzalunga
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro, 5 I-00185, Rome, Italy
| | - Miquel Costas
- QBIS-Cat, Institut de Química Computacional i Catàlisi (IQCC), Departament de Quimica, Universitat de Girona Campus Montilivi, 17071, Girona, Catalonia, Spain
| | - Stefano Di Stefano
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro, 5 I-00185, Rome, Italy
| | - Giorgio Olivo
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR), Sezione Meccanismi di Reazione, c/o Dipartimento di Chimica, Università di Roma "La Sapienza", P.le A. Moro, 5 I-00185, Rome, Italy
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5
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Gong Z, Wang L, Xu Y, Xie D, Qi X, Nam W, Guo M. Enhanced Reactivities of Iron(IV)-Oxo Porphyrin Species in Oxidation Reactions Promoted by Intramolecular Hydrogen-Bonding. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2310333. [PMID: 38477431 PMCID: PMC11109629 DOI: 10.1002/advs.202310333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 02/19/2024] [Indexed: 03/14/2024]
Abstract
High-valent iron-oxo species are one of the common intermediates in both biological and biomimetic catalytic oxidation reactions. Recently, hydrogen-bonding (H-bonding) has been proved to be critical in determining the selectivity and reactivity. However, few examples have been established for mechanistic insights into the H-bonding effect. Moreover, intramolecular H-bonding effect on both C-H activation and oxygen atom transfer (OAT) reactions in synthetic porphyrin model system has not been investigated yet. In this study, a series of heme-containing iron(IV)-oxo porphyrin species with or without intramolecular H-bonding are synthesized and characterized. Kinetic studies revealed that intramolecular H-bonding can significantly enhance the reactivity of iron(IV)-oxo species in OAT, C-H activation, and electron-transfer reactions. This unprecedented unified H-bonding effect is elucidated by theoretical calculations, which showed that intramolecular H-bonding interactions lower the energy of the anti-bonding orbital of iron(IV)-oxo porphyrin species, resulting in the enhanced reactivities in oxidation reactions irrespective of the reaction type. To the best of the knowledge, this is the first extensive investigation on the intramolecular H-bonding effect in heme system. The results show that H-bonding interactions have a unified effect with iron(IV)-oxo porphyrin species in all three investigated reactions.
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Affiliation(s)
- Zhe Gong
- College of Chemistry and Molecular SciencesWuhan UniversityWuhanHubei430072P. R. China
| | - Liwei Wang
- College of Chemistry and Molecular SciencesWuhan UniversityWuhanHubei430072P. R. China
| | - Yiran Xu
- College of Chemistry and Molecular SciencesWuhan UniversityWuhanHubei430072P. R. China
| | - Duanfeng Xie
- College of Chemistry and Molecular SciencesWuhan UniversityWuhanHubei430072P. R. China
| | - Xiaotian Qi
- College of Chemistry and Molecular SciencesWuhan UniversityWuhanHubei430072P. R. China
| | - Wonwoo Nam
- Department of Chemistry and Nano ScienceEwha Womans UniversitySeoul03760South Korea
| | - Mian Guo
- College of Chemistry and Molecular SciencesWuhan UniversityWuhanHubei430072P. R. China
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6
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Singh P, Massie AA, Denler MC, Lee Y, Mayfield JR, Lomax MJA, Singh R, Nordlander E, Jackson TA. C-H Bond Oxidation by Mn IV-Oxo Complexes: Hydrogen-Atom Tunneling and Multistate Reactivity. Inorg Chem 2024; 63:7754-7769. [PMID: 38625043 DOI: 10.1021/acs.inorgchem.4c00186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
The reactivity of six MnIV-oxo complexes in C-H bond oxidation has been examined using a combination of kinetic experiments and computational methods. Variable-temperature studies of the oxidation of 9,10-dihydroanthracene (DHA) and ethylbenzene by these MnIV-oxo complexes yielded activation parameters suitable for evaluating electronic structure computations. Complementary kinetic experiments of the oxidation of deuterated DHA provided evidence for hydrogen-atom tunneling in C-H bond oxidation for all MnIV-oxo complexes. These results are in accordance with the Bell model, where tunneling occurs near the top of the transition-state barrier. Density functional theory (DFT) and DLPNO-CCSD(T1) computations were performed for three of the six MnIV-oxo complexes to probe a previously predicted multistate reactivity model. The DFT computations predicted a thermal crossing from the 4B1 ground state to a 4E state along the C-H bond oxidation reaction coordinate. DLPNO-CCSD(T1) calculations further confirm that the 4E transition state offers a lower energy barrier, reinforcing the multistate reactivity model for these complexes. We discuss how this multistate model can be reconciled with recent computations that revealed that the kinetics of C-H bond oxidation by this set of MnIV-oxo complexes can be well-predicted on the basis of the thermodynamic driving force for these reactions.
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Affiliation(s)
- Priya Singh
- The University of Kansas, Department of Chemistry and Center for Environmentally Beneficial Catalysis, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Allyssa A Massie
- The University of Kansas, Department of Chemistry and Center for Environmentally Beneficial Catalysis, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Melissa C Denler
- The University of Kansas, Department of Chemistry and Center for Environmentally Beneficial Catalysis, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Yuri Lee
- The University of Kansas, Department of Chemistry and Center for Environmentally Beneficial Catalysis, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Jaycee R Mayfield
- The University of Kansas, Department of Chemistry and Center for Environmentally Beneficial Catalysis, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Markell J A Lomax
- The University of Kansas, Department of Chemistry and Center for Environmentally Beneficial Catalysis, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Reena Singh
- Lund University, Chemical Physics, Department of Chemistry, P.O. Box 124, SE-221 00 Lund, Sweden
| | - Ebbe Nordlander
- Lund University, Chemical Physics, Department of Chemistry, P.O. Box 124, SE-221 00 Lund, Sweden
| | - Timothy A Jackson
- The University of Kansas, Department of Chemistry and Center for Environmentally Beneficial Catalysis, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
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7
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Sarkar W, LaDuca A, Wilson JR, Szymczak NK. Iron-Catalyzed C-H Oxygenation Using Perchlorate Enabled by Secondary Sphere Hydrogen Bonds. J Am Chem Soc 2024; 146:10508-10516. [PMID: 38564312 PMCID: PMC11137739 DOI: 10.1021/jacs.3c14433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Perchlorate (ClO4-) is a groundwater pollutant that is challenging to remediate. We report a strategy to use Fe(II) tris(2-pyridylmethyl)amine (TPA) complexes featuring appended aniline hydrogen bonds (H-bonds) to promote ClO4- reduction. These complexes facilitate oxygen atom transfer from ClO4- to PPh3 and C-H oxygenation reactions of organic substrates. Catalytic reactions using 15 mol % afforded excellent yields for oxygenation of anthracene and cyclic alkyl aromatics, and this methodology tolerates aryl halides as well as heterocycles containing either O, S, or N.
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Affiliation(s)
- Writhabrata Sarkar
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, Michigan 48109, United States
| | - Andrew LaDuca
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, Michigan 48109, United States
| | - Jessica R Wilson
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, Michigan 48109, United States
| | - Nathaniel K Szymczak
- Department of Chemistry, University of Michigan, 930 N. University, Ann Arbor, Michigan 48109, United States
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8
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Lionetti D, Suseno S, Shiau AA, de Ruiter G, Agapie T. Redox Processes Involving Oxygen: The Surprising Influence of Redox-Inactive Lewis Acids. JACS AU 2024; 4:344-368. [PMID: 38425928 PMCID: PMC10900226 DOI: 10.1021/jacsau.3c00675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/12/2023] [Accepted: 12/13/2023] [Indexed: 03/02/2024]
Abstract
Metalloenzymes with heteromultimetallic active sites perform chemical reactions that control several biogeochemical cycles. Transformations catalyzed by such enzymes include dioxygen generation and reduction, dinitrogen reduction, and carbon dioxide reduction-instrumental transformations for progress in the context of artificial photosynthesis and sustainable fertilizer production. While the roles of the respective metals are of interest in all these enzymatic transformations, they share a common factor in the transfer of one or multiple redox equivalents. In light of this feature, it is surprising to find that incorporation of redox-inactive metals into the active site of such an enzyme is critical to its function. To illustrate, the presence of a redox-inactive Ca2+ center is crucial in the Oxygen Evolving Complex, and yet particularly intriguing given that the transformation catalyzed by this cluster is a redox process involving four electrons. Therefore, the effects of redox inactive metals on redox processes-electron transfer, oxygen- and hydrogen-atom transfer, and O-O bond cleavage and formation reactions-mediated by transition metals have been studied extensively. Significant effects of redox inactive metals have been observed on these redox transformations; linear free energy correlations between Lewis acidity and the redox properties of synthetic model complexes are observed for several reactions. In this Perspective, these effects and their relevance to multielectron processes will be discussed.
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Affiliation(s)
| | - Sandy Suseno
- Division of Chemistry and
Chemical Engineering, California Institute
of Technology, 1200 East California Boulevard, MC 127-72, Pasadena, California 91125, United States
| | - Angela A. Shiau
- Division of Chemistry and
Chemical Engineering, California Institute
of Technology, 1200 East California Boulevard, MC 127-72, Pasadena, California 91125, United States
| | - Graham de Ruiter
- Division of Chemistry and
Chemical Engineering, California Institute
of Technology, 1200 East California Boulevard, MC 127-72, Pasadena, California 91125, United States
| | - Theodor Agapie
- Division of Chemistry and
Chemical Engineering, California Institute
of Technology, 1200 East California Boulevard, MC 127-72, Pasadena, California 91125, United States
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9
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Rasheed W, Pal N, Aboelenen AM, Banerjee S, Oloo WN, Klein JEMN, Fan R, Xiong J, Guo Y, Que L. NMR and Mössbauer Studies Reveal a Temperature-Dependent Switch from S = 1 to 2 in a Nonheme Oxoiron(IV) Complex with Faster C-H Bond Cleavage Rates. J Am Chem Soc 2024; 146:3796-3804. [PMID: 38299607 PMCID: PMC11238627 DOI: 10.1021/jacs.3c10694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
S = 2 FeIV═O centers generated in the active sites of nonheme iron oxygenases cleave substrate C-H bonds at rates significantly faster than most known synthetic FeIV═O complexes. Unlike the majority of the latter, which are S = 1 complexes, [FeIV(O)(tris(2-quinolylmethyl)amine)(MeCN)]2+ (3) is a rare example of a synthetic S = 2 FeIV═O complex that cleaves C-H bonds 1000-fold faster than the related [FeIV(O)(tris(pyridyl-2-methyl)amine)(MeCN)]2+ complex (0). To rationalize this significant difference, a systematic comparison of properties has been carried out on 0 and 3 as well as related complexes 1 and 2 with mixed pyridine (Py)/quinoline (Q) ligation. Interestingly, 2 with a 2-Q-1-Py donor combination cleaves C-H bonds at 233 K with rates approaching those of 3, even though Mössbauer analysis reveals 2 to be S = 1 at 4 K. At 233 K however, 2 becomes S = 2, as shown by its 1H NMR spectrum. These results demonstrate a unique temperature-dependent spin-state transition from triplet to quintet in oxoiron(IV) chemistry that gives rise to the high C-H bond cleaving reactivity observed for 2.
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Affiliation(s)
- Waqas Rasheed
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Nabhendu Pal
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Ahmed M Aboelenen
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Saikat Banerjee
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Williamson N Oloo
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Johannes E M N Klein
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Ruixi Fan
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Jin Xiong
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Yisong Guo
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Lawrence Que
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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10
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Katoch A, Mandal D. High-valent nonheme Fe(IV)O/Ru(IV)O complexes catalyze C-H activation reactivity and hydrogen tunneling: a comparative DFT investigation. Dalton Trans 2024; 53:2386-2394. [PMID: 38214597 DOI: 10.1039/d3dt03155a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
A comprehensive density functional theory investigation has been presented towards the comparison of the C-H activation reactivity between high-valent iron-oxo and ruthenium-oxo complexes. A total of four compounds, e.g., [Ru(IV)O(tpy-dcbpy)] (1), [Fe(IV)O(tpy-dcbpy)] (1'), [Ru(IV)O(TMCS)] (2), and [Fe(IV)O(TMCS)] (2'), have been considered for this investigation. The macrocyclic ligand framework tpy(dcbpy) implies tpy = 2,2':6',2''-terpyridine, dcbpy = 5,5'-dicarboxy-2,2'-bipyridine, and TMCS is TMC with an axially tethered -SCH2CH2 group. Compounds 1 and 2' are experimentally synthesized standard complexes with Ru and Fe, whereas compounds 1' and 2 were considered to keep the macrocycle intact when switching the central metal atom. Three reactants including benzyl alcohol, ethyl benzene, and dihydroanthracene were selected as substrates for C-H activation. It is noteworthy to mention that Fe(IV)O complexes exhibit higher reactivity than those of their Ru(IV)O counterparts. Furthermore, regardless of the central metal, the complex featuring a tpy-dcbpy macrocycle demonstrates higher reactivity than that of TMCS. Here, a thorough analysis of the reactivity-controlling characteristics-such as spin state, steric factor, distortion energy, energy of the electron acceptor orbital, and quantum mechanical tunneling-was conducted. Fe(IV)O exhibits the exchanged enhanced two-state-reactivity with the quintet reactive state, whereas Ru(IV)O has only a triplet reactive state. Both the distortion energy and acceptor orbital energy are low in the case of Fe(IV)O supporting its higher reactivity. All the investigated C-H activation processes involve a significant contribution from hydrogen tunneling, which is more pronounced in the case of Ru, although it cannot alter the reactivity pattern. Furthermore, it has also been found that, independent of the central metal, aliphatic hydroxylation is always preferable to aromatic hydroxylation. Overall, this work is successful in establishing and investigating the cause of enzymes' natural preference for Fe over Ru as a cofactor for C-H activation enzymes.
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Affiliation(s)
- Akanksha Katoch
- Department of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala-147001, Punjab, India.
| | - Debasish Mandal
- Department of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala-147001, Punjab, India.
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11
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Devi T, Dutta K, Deutscher J, Mebs S, Kuhlmann U, Haumann M, Cula B, Dau H, Hildebrandt P, Ray K. A high-spin alkylperoxo-iron(iii) complex with cis-anionic ligands: implications for the superoxide reductase mechanism. Chem Sci 2024; 15:528-533. [PMID: 38179538 PMCID: PMC10762717 DOI: 10.1039/d3sc05603a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 12/05/2023] [Indexed: 01/06/2024] Open
Abstract
The N3O macrocycle of the 12-TMCO ligand stabilizes a high spin (S = 5/2) [FeIII(12-TMCO)(OOtBu)Cl]+ (3-Cl) species in the reaction of [FeII(12-TMCO)(OTf)2] (1-(OTf)2) with tert-butylhydroperoxide (tBuOOH) in the presence of tetraethylammonium chloride (NEt4Cl) in acetonitrile at -20 °C. In the absence of NEt4Cl the oxo-iron(iv) complex 2 [FeIV(12-TMCO)(O)(CH3CN)]2+ is formed, which can be further converted to 3-Cl by adding NEt4Cl and tBuOOH. The role of the cis-chloride ligand in the stabilization of the FeIII-OOtBu moiety can be extended to other anions including the thiolate ligand relevant to the enzyme superoxide reductase (SOR). The present study underlines the importance of subtle electronic changes and secondary interactions in the stability of the biologically relevant metal-dioxygen intermediates. It also provides some rationale for the dramatically different outcomes of the chemistry of iron(iii)peroxy intermediates formed in the catalytic cycles of SOR (Fe-O cleavage) and cytochrome P450 (O-O bond lysis) in similar N4S coordination environments.
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Affiliation(s)
- Tarali Devi
- Institut für Chemie, Humboldt-Universitat zu Berlin Brook-Taylor-Straße 2 12489 Berlin Germany
- Department of Inorganic and Physical Chemistry, Indian Institute of Science Bangalore Karnataka-560012 India
| | - Kuheli Dutta
- Institut für Chemie, Humboldt-Universitat zu Berlin Brook-Taylor-Straße 2 12489 Berlin Germany
| | - Jennifer Deutscher
- Institut für Chemie, Humboldt-Universitat zu Berlin Brook-Taylor-Straße 2 12489 Berlin Germany
| | - Stefan Mebs
- Department of Physics, Freie Universität Berlin Arnimallee 14 14195 Berlin Germany
| | - Uwe Kuhlmann
- Institut für Chemie, Technische Universität Berlin Fakultät II, Straße des 17. Juni 135 10623 Berlin Germany
| | - Michael Haumann
- Department of Physics, Freie Universität Berlin Arnimallee 14 14195 Berlin Germany
| | - Beatrice Cula
- Institut für Chemie, Humboldt-Universitat zu Berlin Brook-Taylor-Straße 2 12489 Berlin Germany
| | - Holger Dau
- Department of Physics, Freie Universität Berlin Arnimallee 14 14195 Berlin Germany
| | - Peter Hildebrandt
- Institut für Chemie, Technische Universität Berlin Fakultät II, Straße des 17. Juni 135 10623 Berlin Germany
| | - Kallol Ray
- Institut für Chemie, Humboldt-Universitat zu Berlin Brook-Taylor-Straße 2 12489 Berlin Germany
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12
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Britto NJ, Sen A, Rajaraman G. Unravelling the Effect of Acid-Driven Electron Transfer in High-Valent Fe IV =O/Mn IV =O Species and Its Implications for Reactivity. Chem Asian J 2023; 18:e202300773. [PMID: 37855305 DOI: 10.1002/asia.202300773] [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: 09/05/2023] [Revised: 10/12/2023] [Accepted: 10/16/2023] [Indexed: 10/20/2023]
Abstract
The electron transfer (ET) step is one of the crucial processes in biochemical redox reactions that occur in nature and has been established as a key step in dictating the reactivity of high-valent metal-oxo species. Although metalloenzymes possessing metal-oxo units at their active site are typically associated with outer-sphere electron transfer (OSET) processes, biomimetic models, in contrast, have been found to manifest either an inner-sphere electron transfer (ISET) or OSET mechanism. This distinction is clearly illustrated through the behaviour of [(N4Py)MnIV (O)]2+ (1) and [(N4Py)FeIV (O)]2+ (2) complexes, where complex 1 showcases an OSET mechanism, while complex 2 exhibits an ISET mechanism, especially evident in their reactions involving C-H bond activation and oxygen atom transfer reactions in the presence of a Lewis/Bronsted acid. However, the precise reason for this puzzling difference remains elusive. This work unveils the origin of the perplexing inner-sphere vs outer-sphere electron transfer process (ISET vs OSET) in [(N4Py)MnIV (O)]2+ (1) and [(N4Py)FeIV (O)]2+ (2) species in the presence of Bronsted acid. The calculations indicate that when the substrate (toluene) approaches both 1 and 2 that is hydrogen bonded with two HOTf molecules (denoted as 1-HOTf and 2-HOTf, respectively), proton transfer from one of the HOTf molecules to the metal-oxo unit is triggered and a simultaneous electron transfer occurs from toluene to the metal centre. Interestingly, the preference for OSET by 1-HOTf is found to originate from the choice of MnIV =O centre to abstract spin-down (β) electron from toluene to its δ(dxy ) orbital. On the other hand, in 2-HOTf, a spin state inversion from triplet to quintet state takes place during the proton (from HOTf) coupled electron transfer (from toluene) preferring a spin-up (α) electron abstraction to its σ* (dz 2 ) orbital mediated by HOTf giving rise to ISET. In addition, 2-HOTf was calculated to possess a larger reorganisation energy, which facilitates the ISET process via the acid. The absence of spin-inversion and smaller reorganisation energy switch the mechanism to OSET for 1-HOTf. Therefore, for the first time, the significance of spin-state and spin-inversion in the electron transfer process has been identified and demonstrated within the realm of high-valent metal-oxo chemistry. This discovery holds implications for the potential involvement of high-valent Mn-oxo species in performing similar transformative processes within Photosystem II.
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Affiliation(s)
| | - Asmita Sen
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400 076, India
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400 076, India
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13
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Li Y, Singh R, Sinha A, Lisensky GC, Haukka M, Nilsson J, Yiga S, Demeshko S, Gross SJ, Dechert S, Gonzalez A, Farias G, Wendt OF, Meyer F, Nordlander E. Nonheme Fe IV═O Complexes Supported by Four Pentadentate Ligands: Reactivity toward H- and O- Atom Transfer Processes. Inorg Chem 2023; 62:18338-18356. [PMID: 37913548 PMCID: PMC10647104 DOI: 10.1021/acs.inorgchem.3c02526] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 10/06/2023] [Accepted: 10/11/2023] [Indexed: 11/03/2023]
Abstract
Four new pentadentate N5-donor ligands, [N-(1-methyl-2-imidazolyl)methyl-N-(2-pyridyl)-methyl-N-(bis-2-pyridylmethyl)-amine] (L1), [N-bis(1-methyl-2-imidazolyl)methyl-N-(bis-2-pyridylmethyl)amine] (L2), (N-(isoquinolin-3-ylmethyl)-1,1-di(pyridin-2-yl)-N-(pyridin-2-ylmethyl)methanamine (L3), and N,N-bis(isoquinolin-3-ylmethyl)-1,1-di(pyridin-2-yl)methanamine (L4), have been synthesized based on the N4Py ligand framework, where one or two pyridyl arms of the N4Py parent are replaced by (N-methyl)imidazolyl or N-(isoquinolin-3-ylmethyl) moieties. Using these four pentadentate ligands, the mononuclear complexes [FeII(CH3CN)(L1)]2+ (1a), [FeII(CH3CN)(L2)]2+ (2a), [FeII(CH3CN)(L3)]2+ (3a), and [FeII(CH3CN)(L4)]2+ (4a) have been synthesized and characterized. The half-wave potentials (E1/2) of the complexes become more positive in the order: 2a < 1a < 4a ≤ 3a ≤ [Fe(N4Py)(CH3CN)]2+. The order of redox potentials correlates well with the Fe-Namine distances observed by crystallography, which are 2a > 1a ≥ 4a > 3a ≥ [Fe(N4Py)(CH3CN)]2+. The corresponding ferryl complexes [FeIV(O)(L1)]2+ (1b), [FeIV(O)(L2)]2+ (2b), [FeIV(O)(L3)]2+ (3b), and [FeIV(O)(L4)]2+ (4b) were prepared by the reaction of the ferrous complexes with isopropyl 2-iodoxybenzoate (IBX ester) in acetonitrile. The greenish complexes 3b and 4b were also isolated in the solid state by the reaction of the ferrous complexes in CH3CN with ceric ammonium nitrate in water. Mössbauer spectroscopy and magnetic measurements (using superconducting quantum interference device) show that the four complexes 1b, 2b, 3b, and 4b are low-spin (S = 1) FeIV═O complexes. UV/vis spectra of the four FeIV═O complexes in acetonitrile show typical long-wavelength absorptions of around 700 nm, which are expected for FeIV═O complexes with N4Py-type ligands. The wavelengths of these absorptions decrease in the following order: 721 nm (2b) > 706 nm (1b) > 696 nm (4b) > 695 nm (3b) = 695 nm ([FeIV(O) (N4Py)]2+), indicating that the replacement of the pyridyl arms with (N-methyl) imidazolyl moieties makes L1 and L2 exert weaker ligand fields than the parent N4Py ligand, while the ligand field strengths of L3 and L4 are similar to the N4Py parent despite the replacement of the pyridyl arms with N-(isoquinolin-3-ylmethyl) moieties. Consequently, complexes 1b and 2b tend to be less stable than the parent [FeIV(O)(N4Py)]2+ complex: the half-life sequence at room temperature is 1.67 h (2b) < 16 h (1b) < 45 h (4b) < 63 h (3b) ≈ 60 h ([FeIV(O)(N4Py)]2+). Compared to the parent complex, 1b and 2b exhibit enhanced reactivity in both the oxidation of thioanisole in the oxygen atom transfer (OAT) reaction and the oxygenation of C-H bonds of aromatic and aliphatic substrates, presumed to occur via an oxygen rebound process. Furthermore, the second-order rate constants for hydrogen atom transfer (HAT) reactions affected by the ferryl complexes can be directly related to the C-H bond dissociation energies of a range of substrates that have been studied. Using either IBX ester or H2O2 as an oxidant, all four new FeII complexes display good performance in catalytic reactions involving both HAT and OAT reactions.
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Affiliation(s)
- Yong Li
- Chemical
Physics, Department of Chemistry, Lund University, Box 124, Lund SE-221 00, Sweden
| | - Reena Singh
- Chemical
Physics, Department of Chemistry, Lund University, Box 124, Lund SE-221 00, Sweden
| | - Arup Sinha
- Chemical
Physics, Department of Chemistry, Lund University, Box 124, Lund SE-221 00, Sweden
| | - George C. Lisensky
- Department
of Chemistry, Beloit College, 700 College Street, Beloit, Wisconsin 53511, United States
| | - Matti Haukka
- Department
of Chemistry, University of Jyväskylä, P.O. Box-35, Jyväskylä FI-40014, Finland
| | - Justin Nilsson
- Chemical
Physics, Department of Chemistry, Lund University, Box 124, Lund SE-221 00, Sweden
| | - Solomon Yiga
- Centre
for Analysis and Synthesis, Department of Chemistry, Lund University, P.O. Box 124, Lund SE-22100, Sweden
| | - Serhiy Demeshko
- Georg-August
Universität Göttingen, Institut
für Anorganische Chemie, Tammanstrasse 4, Göttingen D-37077, Germany
| | - Sophie Jana Gross
- Georg-August
Universität Göttingen, Institut
für Anorganische Chemie, Tammanstrasse 4, Göttingen D-37077, Germany
| | - Sebastian Dechert
- Georg-August
Universität Göttingen, Institut
für Anorganische Chemie, Tammanstrasse 4, Göttingen D-37077, Germany
| | - Ana Gonzalez
- MAX IV Laboratory, Lund University, P.O.
Box 118, Lund SE-221 00, Sweden
| | - Giliandro Farias
- Department
of Chemistry, Federal University of Santa
Catarina, Florianópolis 88040900, Santa Catarina, Brazil
| | - Ola F. Wendt
- Centre
for Analysis and Synthesis, Department of Chemistry, Lund University, P.O. Box 124, Lund SE-22100, Sweden
| | - Franc Meyer
- Georg-August
Universität Göttingen, Institut
für Anorganische Chemie, Tammanstrasse 4, Göttingen D-37077, Germany
| | - Ebbe Nordlander
- Chemical
Physics, Department of Chemistry, Lund University, Box 124, Lund SE-221 00, Sweden
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14
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Hou K, Börgel J, Jiang HZH, SantaLucia DJ, Kwon H, Zhuang H, Chakarawet K, Rohde RC, Taylor JW, Dun C, Paley MV, Turkiewicz AB, Park JG, Mao H, Zhu Z, Alp EE, Zhao J, Hu MY, Lavina B, Peredkov S, Lv X, Oktawiec J, Meihaus KR, Pantazis DA, Vandone M, Colombo V, Bill E, Urban JJ, Britt RD, Grandjean F, Long GJ, DeBeer S, Neese F, Reimer JA, Long JR. Reactive high-spin iron(IV)-oxo sites through dioxygen activation in a metal-organic framework. Science 2023; 382:547-553. [PMID: 37917685 DOI: 10.1126/science.add7417] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 09/24/2023] [Indexed: 11/04/2023]
Abstract
In nature, nonheme iron enzymes use dioxygen to generate high-spin iron(IV)=O species for a variety of oxygenation reactions. Although synthetic chemists have long sought to mimic this reactivity, the enzyme-like activation of O2 to form high-spin iron(IV) = O species remains an unrealized goal. Here, we report a metal-organic framework featuring iron(II) sites with a local structure similar to that in α-ketoglutarate-dependent dioxygenases. The framework reacts with O2 at low temperatures to form high-spin iron(IV) = O species that are characterized using in situ diffuse reflectance infrared Fourier transform, in situ and variable-field Mössbauer, Fe Kβ x-ray emission, and nuclear resonance vibrational spectroscopies. In the presence of O2, the framework is competent for catalytic oxygenation of cyclohexane and the stoichiometric conversion of ethane to ethanol.
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Affiliation(s)
- Kaipeng Hou
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Jonas Börgel
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Henry Z H Jiang
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | - Daniel J SantaLucia
- Max Planck Institute for Chemical Energy Conversion, D-45470 Mülheim an der Ruhr, Germany
- Max-Planck-Institut für Kohlenforschung, D-45470 Mülheim an der Ruhr, Germany
| | - Hyunchul Kwon
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | - Hao Zhuang
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720, USA
- Department of Materials Science and Engineering, University of California, Berkeley, CA 94720, USA
| | | | - Rachel C Rohde
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | - Jordan W Taylor
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | - Chaochao Dun
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Maria V Paley
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Ari B Turkiewicz
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | - Jesse G Park
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | - Haiyan Mao
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720, USA
| | - Ziting Zhu
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Materials Science and Engineering, University of California, Berkeley, CA 94720, USA
| | - E Ercan Alp
- Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Jiyong Zhao
- Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Michael Y Hu
- Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Barbara Lavina
- Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA
- Center for Advanced Radiation Sources, The University of Chicago, Chicago, IL 60637, USA
| | - Sergey Peredkov
- Max Planck Institute for Chemical Energy Conversion, D-45470 Mülheim an der Ruhr, Germany
| | - Xudong Lv
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | - Julia Oktawiec
- Department of Chemistry, Northwestern University, Evanston, IL 60208, USA
| | - Katie R Meihaus
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
| | | | - Marco Vandone
- Department of Chemistry, University of Milan, 20133 Milan, Italy
| | - Valentina Colombo
- Department of Chemistry, University of Milan, 20133 Milan, Italy
- Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali (INSTM), UdR Milano, Via Golgi 19, 20133 Milano, Italy
| | - Eckhard Bill
- Max Planck Institute for Chemical Energy Conversion, D-45470 Mülheim an der Ruhr, Germany
| | - Jeffrey J Urban
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - R David Britt
- Department of Chemistry, University of California, Davis, CA 95616, USA
- Miller Institute for Basic Research in Science, University of California, Berkeley CA 94720, USA
| | - Fernande Grandjean
- Department of Chemistry, Missouri University of Science and Technology, University of Missouri, Rolla, MO 65409, USA
| | - Gary J Long
- Department of Chemistry, Missouri University of Science and Technology, University of Missouri, Rolla, MO 65409, USA
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion, D-45470 Mülheim an der Ruhr, Germany
| | - Frank Neese
- Max-Planck-Institut für Kohlenforschung, D-45470 Mülheim an der Ruhr, Germany
| | - Jeffrey A Reimer
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720, USA
| | - Jeffrey R Long
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720, USA
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15
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Kulmaczewski R, Halcrow MA. Iron(II) complexes of 2,6-bis(imidazo[1,2- a]pyridin-2-yl)pyridine and related ligands with annelated distal heterocyclic donors. Dalton Trans 2023; 52:14928-14940. [PMID: 37799008 DOI: 10.1039/d3dt02747c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/07/2023]
Abstract
Following a published synthesis of 2,6-bis(imidazo[1,2-a]pyridin-2-yl)pyridine (L1), treatment of α,α'-dibromo-2,6-diacetylpyridine with 2 equiv. 2-aminopyrimidine or 2-aminoquinoline in refluxing acetonitrile respectively gives 2,6-bis(imidazo[1,2-a]pyrimidin-2-yl)pyridine (L2) and 2,6-bis(imidazo[1,2-a]quinolin-2-yl)pyridine (L3). Solvated crystals of [Fe(L1)2][BF4]2 (1[BF4]2) and [Fe(L2)2][BF4]2 (2[BF4]2) are mostly high-spin, although one solvate of 1[BF4]2 undergoes thermal spin-crossover on cooling. The iron coordination geometry is consistently distorted in crystals of 2[BF4]2 which may reflect the influence of intramolecular, inter-ligand N⋯π interactions on the molecular conformation. Only 1 : 1 Fe : L3 complexes were observed in solution, or isolated in the solid state; a crystal structure of [FeBr(py)2L3]Br·0.5H2O (py = pyridine) is presented. A solvate crystal structure of high-spin [Fe(L4)2][BF4]2 (L4 = 2,6-di{quinolin-2-yl}pyridine; 4[BF4]2) is also described, which exhibits a highly distorted six-coordinate geometry with a helical ligand conformation. The iron(II) complexes are high-spin in solution at room temperature, but 1[BF4]2 and 2[BF4]2 undergo thermal spin-crossover equilibria on cooling. All the compounds exhibit a ligand-based emission in solution at room temperature. Gas phase DFT calculations mostly reproduce the spin state properties of the complexes, but show small anomalies attributed to intramolecular, inter-ligand dispersion interactions in the sterically crowded molecules.
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Affiliation(s)
- Rafal Kulmaczewski
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, UK LS2 9JT.
| | - Malcolm A Halcrow
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, UK LS2 9JT.
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16
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Paris JC, Hu S, Wen A, Weitz AC, Cheng R, Gee LB, Tang Y, Kim H, Vegas A, Chang WC, Elliott SJ, Liu P, Guo Y. An S=1 Iron(IV) Intermediate Revealed in a Non-Heme Iron Enzyme-Catalyzed Oxidative C-S Bond Formation. Angew Chem Int Ed Engl 2023; 62:e202309362. [PMID: 37640689 PMCID: PMC10592081 DOI: 10.1002/anie.202309362] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 08/11/2023] [Accepted: 08/28/2023] [Indexed: 08/31/2023]
Abstract
Ergothioneine (ESH) and ovothiol A (OSHA) are two natural thiol-histidine derivatives. ESH has been implicated as a longevity vitamin and OSHA inhibits the proliferation of hepatocarcinoma. The key biosynthetic step of ESH and OSHA in the aerobic pathways is the O2 -dependent C-S bond formation catalyzed by non-heme iron enzymes (e.g., OvoA in ovothiol biosynthesis), but due to the lack of identification of key reactive intermediate the mechanism of this novel reaction is unresolved. In this study, we report the identification and characterization of a kinetically competent S=1 iron(IV) intermediate supported by a four-histidine ligand environment (three from the protein residues and one from the substrate) in enabling C-S bond formation in OvoA from Methyloversatilis thermotoleran, which represents the first experimentally observed intermediate spin iron(IV) species in non-heme iron enzymes. Results reported in this study thus set the stage to further dissect the mechanism of enzymatic oxidative C-S bond formation in the OSHA biosynthesis pathway. They also afford new opportunities to study the structure-function relationship of high-valent iron intermediates supported by a histidine rich ligand environment.
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Affiliation(s)
- Jared C Paris
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Ave., Pittsburgh, PA 15213, USA
| | - Sha Hu
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA 02215, USA
| | - Aiwen Wen
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA 02215, USA
| | - Andrew C Weitz
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA 02215, USA
| | - Ronghai Cheng
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA 02215, USA
| | - Leland B Gee
- LCLS, SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, CA 94025, USA
| | - Yijie Tang
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Ave., Pittsburgh, PA 15213, USA
| | - Hyomin Kim
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA 02215, USA
| | - Arturo Vegas
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA 02215, USA
| | - Wei-Chen Chang
- Department of Chemistry, North Carolina State University, Raleigh, NC 27695, USA
| | - Sean J Elliott
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA 02215, USA
| | - Pinghua Liu
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, MA 02215, USA
| | - Yisong Guo
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Ave., Pittsburgh, PA 15213, USA
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17
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Yamaguchi K, Isobe H, Shoji M, Kawakami T, Miyagawa K. The Nature of the Chemical Bonds of High-Valent Transition-Metal Oxo (M=O) and Peroxo (MOO) Compounds: A Historical Perspective of the Metal Oxyl-Radical Character by the Classical to Quantum Computations. Molecules 2023; 28:7119. [PMID: 37894598 PMCID: PMC10609222 DOI: 10.3390/molecules28207119] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 10/08/2023] [Accepted: 10/10/2023] [Indexed: 10/29/2023] Open
Abstract
This review article describes a historical perspective of elucidation of the nature of the chemical bonds of the high-valent transition metal oxo (M=O) and peroxo (M-O-O) compounds in chemistry and biology. The basic concepts and theoretical backgrounds of the broken-symmetry (BS) method are revisited to explain orbital symmetry conservation and orbital symmetry breaking for the theoretical characterization of four different mechanisms of chemical reactions. Beyond BS methods using the natural orbitals (UNO) of the BS solutions, such as UNO CI (CC), are also revisited for the elucidation of the scope and applicability of the BS methods. Several chemical indices have been derived as the conceptual bridges between the BS and beyond BS methods. The BS molecular orbital models have been employed to explain the metal oxyl-radical character of the M=O and M-O-O bonds, which respond to their radical reactivity. The isolobal and isospin analogy between carbonyl oxide R2C-O-O and metal peroxide LFe-O-O has been applied to understand and explain the chameleonic chemical reactivity of these compounds. The isolobal and isospin analogy among Fe=O, O=O, and O have also provided the triplet atomic oxygen (3O) model for non-heme Fe(IV)=O species with strong radical reactivity. The chameleonic reactivity of the compounds I (Cpd I) and II (Cpd II) is also explained by this analogy. The early proposals obtained by these theoretical models have been examined based on recent computational results by hybrid DFT (UHDFT), DLPNO CCSD(T0), CASPT2, and UNO CI (CC) methods and quantum computing (QC).
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Affiliation(s)
- Kizashi Yamaguchi
- SANKEN, Osaka University, Ibaraki 567-0047, Osaka, Japan
- Center for Quantum Information and Quantum Biology (QIQB), Osaka University, Toyonaka 560-0043, Osaka, Japan
| | - Hiroshi Isobe
- Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Okayama, Japan;
| | - Mitsuo Shoji
- Center for Computational Sciences, University of Tsukuba, Tsukuba 305-8577, Ibaraki, Japan; (M.S.); (K.M.)
| | - Takashi Kawakami
- Department of Chemistry, Graduate School of Science, Osaka University, Toyonaka 560-0043, Osaka, Japan;
| | - Koichi Miyagawa
- Center for Computational Sciences, University of Tsukuba, Tsukuba 305-8577, Ibaraki, Japan; (M.S.); (K.M.)
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18
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Braun A, Gee LB, Mara MW, Hill EA, Kroll T, Nordlund D, Sokaras D, Glatzel P, Hedman B, Hodgson KO, Borovik AS, Baker ML, Solomon EI. X-ray Spectroscopic Study of the Electronic Structure of a Trigonal High-Spin Fe(IV)═O Complex Modeling Non-Heme Enzyme Intermediates and Their Reactivity. J Am Chem Soc 2023; 145:18977-18991. [PMID: 37590931 PMCID: PMC10631461 DOI: 10.1021/jacs.3c06181] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/19/2023]
Abstract
Fe K-edge X-ray absorption spectroscopy (XAS) has long been used for the study of high-valent iron intermediates in biological and artificial catalysts. 4p-mixing into the 3d orbitals complicates the pre-edge analysis but when correctly understood via 1s2p resonant inelastic X-ray scattering and Fe L-edge XAS, it enables deeper insight into the geometric structure and correlates with the electronic structure and reactivity. This study shows that in addition to the 4p-mixing into the 3dz2 orbital due to the short iron-oxo bond, the loss of inversion in the equatorial plane leads to 4p mixing into the 3dx2-y2,xy, providing structural insight and allowing the distinction of 6- vs 5-coordinate active sites as shown through application to the Fe(IV)═O intermediate of taurine dioxygenase. Combined with O K-edge XAS, this study gives an unprecedented experimental insight into the electronic structure of Fe(IV)═O active sites and their selectivity for reactivity enabled by the π-pathway involving the 3dxz/yz orbitals. Finally, the large effect of spin polarization is experimentally assigned in the pre-edge (i.e., the α/β splitting) and found to be better modeled by multiplet simulations rather than by commonly used time-dependent density functional theory.
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Affiliation(s)
- Augustin Braun
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
| | - Leland B Gee
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
| | - Michael W Mara
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
| | - Ethan A Hill
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Thomas Kroll
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
| | - Dennis Nordlund
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
| | - Dimosthenis Sokaras
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
| | - Pieter Glatzel
- ESRF-The European Synchrotron Radiation Facility, 71 Avenue des Martyrs, Grenoble 38000, France
| | - Britt Hedman
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
| | - Keith O Hodgson
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
| | - A S Borovik
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Michael L Baker
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
- Department of Chemistry, The University of Manchester, Manchester M13 9PL, U.K
- The University of Manchester at Harwell, Diamond Light Source, Harwell Campus, Didcot OX11 0DE, U.K
| | - Edward I Solomon
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States
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19
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Xiong J, Liu Q, Lavina B, Hu MY, Zhao J, Alp EE, Deng L, Ye S, Guo Y. Spin polarization assisted facile C-H activation by an S = 1 iron(iv)-bisimido complex: a comprehensive spectroscopic and theoretical investigation. Chem Sci 2023; 14:2808-2820. [PMID: 36937578 PMCID: PMC10016330 DOI: 10.1039/d2sc06273a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 02/14/2023] [Indexed: 02/17/2023] Open
Abstract
High valent iron terminal imido species (Fe[double bond, length as m-dash]NR) have been shown to be key reactive intermediates in C-H functionalization. However, the detailed structure-reactivity relationship in Fe[double bond, length as m-dash]NR species derived from studies of structurally well-characterized high-valent Fe[double bond, length as m-dash]NR complexes are still scarce, and the impact of imido N-substituents (electron-donating vs. electron-withdrawing) on their electronic structures and reactivities has not been thoroughly explored. In this study, we report spectroscopic and computational studies on a rare S = 1 iron(iv)-bisimido complex featuring trifluoromethyl groups on the imido N-substituents, [(IPr)Fe(NC(CF3)2Ph)2] (2), and two closely related S = 0 congeners bearing alkyl and aryl substituents, [(IPr)Fe(NC(CMe3)2Ph)2] (3) and [(IPr)Fe(NDipp)2] (1), respectively. Compared with 1 and 3, 2 exhibits a decreased Fe[double bond, length as m-dash]NR bond covalency due to the electron-withdrawing and the steric effect of the N-substituents, which further leads to a pseudo doubly degenerate ground electronic structure and spin polarization induced β spin density on the imido nitrogens. This unique electronic structure, which differs from those of the well-studied Fe(iv)-oxido complexes and many previously reported Fe(iv)-imido complexes, provides both kinetic and thermodynamic advantages for facile C-H activation, compared to the S = 0 counterparts.
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Affiliation(s)
- Jin Xiong
- Department of Chemistry, Carnegie Mellon University Pittsburgh Pennsylvania 15213 USA
| | - Qing Liu
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences Shanghai 200032 P. R. China
| | - Barbara Lavina
- Advanced Photon Source, Argonne National Laboratory Argonne Illinois 60439 USA
- Center for Advanced Radiation Sources, University of Chicago Chicago Illinois 60439 USA
| | - Michael Y Hu
- Advanced Photon Source, Argonne National Laboratory Argonne Illinois 60439 USA
| | - Jiyong Zhao
- Advanced Photon Source, Argonne National Laboratory Argonne Illinois 60439 USA
| | - Esen E Alp
- Advanced Photon Source, Argonne National Laboratory Argonne Illinois 60439 USA
| | - Liang Deng
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences Shanghai 200032 P. R. China
| | - Shengfa Ye
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences Dalian 116023 P. R. China
| | - Yisong Guo
- Department of Chemistry, Carnegie Mellon University Pittsburgh Pennsylvania 15213 USA
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20
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Dantignana V, Pérez-Segura MC, Besalú-Sala P, Delgado-Pinar E, Martínez-Camarena Á, Serrano-Plana J, Álvarez-Núñez A, Castillo CE, García-España E, Luis JM, Basallote MG, Costas M, Company A. Characterization of a Ferryl Flip in Electronically Tuned Nonheme Complexes. Consequences in Hydrogen Atom Transfer Reactivity. Angew Chem Int Ed Engl 2023; 62:e202211361. [PMID: 36305539 PMCID: PMC10107328 DOI: 10.1002/anie.202211361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Indexed: 12/04/2022]
Abstract
Two oxoiron(IV) isomers (R 2a and R 2b) of general formula [FeIV (O)(R PyNMe3 )(CH3 CN)]2+ are obtained by reaction of their iron(II) precursor with NBu4 IO4 . The two isomers differ in the position of the oxo ligand, cis and trans to the pyridine donor. The mechanism of isomerization between R 2a and R 2b has been determined by kinetic and computational analyses uncovering an unprecedented path for interconversion of geometrical oxoiron(IV) isomers. The activity of the two oxoiron(IV) isomers in hydrogen atom transfer (HAT) reactions shows that R 2a reacts one order of magnitude faster than R 2b, which is explained by a repulsive noncovalent interaction between the ligand and the substrate in R 2b. Interestingly, the electronic properties of the R substituent in the ligand pyridine ring do not have a significant effect on reaction rates. Overall, the intrinsic structural aspects of each isomer define their relative HAT reactivity, overcoming changes in electronic properties of the ligand.
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Affiliation(s)
- Valeria Dantignana
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - M Carmen Pérez-Segura
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Instituto de Biomoléculas (INBIO), Universidad de Cádiz, Puerto Real, 11510, Cádiz, Spain
| | - Pau Besalú-Sala
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Estefanía Delgado-Pinar
- Departamento de Química Inorgánica, Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, C/Catedrático José Beltrán, Paterna, 46980, Valencia 2, Spain
| | - Álvaro Martínez-Camarena
- Departamento de Química Inorgánica, Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, C/Catedrático José Beltrán, Paterna, 46980, Valencia 2, Spain
| | - Joan Serrano-Plana
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Andrea Álvarez-Núñez
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Carmen E Castillo
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Instituto de Biomoléculas (INBIO), Universidad de Cádiz, Puerto Real, 11510, Cádiz, Spain
| | - Enrique García-España
- Departamento de Química Inorgánica, Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, C/Catedrático José Beltrán, Paterna, 46980, Valencia 2, Spain
| | - Josep M Luis
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Manuel G Basallote
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Instituto de Biomoléculas (INBIO), Universidad de Cádiz, Puerto Real, 11510, Cádiz, Spain
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Anna Company
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
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21
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Ansari M, Rajaraman G. Comparative oxidative ability of mononuclear and dinuclear high-valent iron-oxo species towards the activation of methane: does the axial/bridge atom modulate the reactivity? Dalton Trans 2023; 52:308-325. [PMID: 36504243 DOI: 10.1039/d2dt02559k] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Over the years, mononuclear FeIVO species have been extensively studied, but the presence of dinuclear FeIVO species in soluble methane monooxygenase (sMMO) has inspired the development of biomimic models that could activate inert substrates such as methane. There are some successful attempts; particularly the [(Por)(m-CBA) FeIV(μ-N)FeIV(O)(Por˙+)]- species has been reported to activate methane and yield decent catalytic turnover numbers and therefore regarded as the closest to the sMMO enzyme functional model, as no mononuclear FeIVO analogues could achieve this feat. In this work, we have studied a series of mono and dinuclear models using DFT and ab initio DLPNO-CCSD(T) calculations to probe the importance of nuclearity in enhancing the reactivity. We have probed the catalytic activities of four complexes: [(HO)FeIV(O)(Por)]- (1), [(HO)FeIV(O)(Por˙+)] (2), μ-oxo dinuclear iron species [(Por)(m-CBA)FeIV(μ-O)FeIV(O) (Por˙+)]- (3) and N-bridged dinuclear iron species [(Por)(m-CBA)FeIV(μ-N)FeIV(O)(Por˙+)]- (4) towards the activation of methane. Additionally, calculations were performed on the mononuclear models [(X)FeIV(O)(Por˙+)]n {X = N 4a (n = -2), NH 4b (n = -1) and NH24c (n = 0)} to understand the role of nuclearity in the reactivity. DFT calculations performed on species 1-4 suggest an interesting variation among them, with species 1-3 possessing an intermediate spin (S = 1) as a ground state and species 4 possessing a high-spin (S = 2) as a ground state. Furthermore, the two FeIV centres in species 3 and 4 are antiferromagnetically coupled, yielding a singlet state with a distinct difference in their electronic structure. On the other hand, species 2 exhibits a ferromagnetic coupling between the FeIV and the Por˙+ moiety. Our calculations suggest that the higher barriers for the C-H bond activation of methane and the rebound step for species 1 and 3 are very high in energy, rendering them unreactive towards methane, while species 2 and 4 have lower barriers, suggesting their reactivity towards methane. Studies on the system reveal that model 4a has multiple FeN bonds facilitating greater reactivity, whereas the other two models have longer Fe-N bonds and less radical character with steeper barriers. Strong electronic cooperativity is found to be facilitated by the bridging nitride atom, and this cooperativity is suppressed by substituents such as oxygen, rendering them inactive. Thus, our study unravels that apart from enhancing the nuclearity, bridging atoms that facilitate strong cooperation between the metals are required to activate very inert substrates such as methane, and our results are broadly in agreement with earlier experimental findings.
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Affiliation(s)
- Mursaleem Ansari
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India.
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai 400076, India.
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22
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Setifi Z, Cubillán N, Glidewell C, Gil DM, Torabi E, Morales-Toyo M, Dege N, Setifi F, Mirzaei M. A combined experimental, Hirshfeld surface analysis, and theoretical study on fac-[tri(azido)(tris(2-pyridyl)amine)iron(III)]. Polyhedron 2023. [DOI: 10.1016/j.poly.2023.116320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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23
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Liao G, Mei F, Chen Z, Yin G. Lewis acid improved dioxygen activation by a non-heme iron(II) complex towards tryptophan 2,3-dioxygenase activity for olefin oxygenation. Dalton Trans 2022; 51:18024-18032. [PMID: 36373374 DOI: 10.1039/d2dt02769k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Dioxygen activation and catalysis around ambient temperature is a long-standing challenge in chemistry. Inspired by the significant roles of the hydrogen bond network in dioxygen activation and catalysis by redox enzymes, this work presents a Lewis acid improved dioxygen activation by an FeII(BPMEN)(OTf)2 complex towards tryptophan 2,3-dioxygenase (TDO) activity for 3-methylindole and common olefinic CC bond oxygenation and cleavage (enzymatic Brønsted acid vs. chemical Lewis acid). It was found that the presence of a Lewis acid such as Sc3+ could substantially improve olefinic CC bond oxygenation and cleavage activity through FeII(BPMEN)(OTf)2 catalyzed dioxygen activation. Notably, a more negative ρ value in the Hammett plot of para-substituted styrene oxygenations was observed in the presence of a stronger Lewis acid, disclosing the enhanced electrophilic oxygenation capability of the putative iron(III) superoxo species through its electrostatic interaction with a stronger Lewis acid. Thereof, this work has demonstrated a new strategy in catalyst design for dioxygen activation and catalysis for olefin oxygenation, a significant process in the chemical industry.
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Affiliation(s)
- Guangjian Liao
- School of Chemistry and Chemical Engineering, Key laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, PR China.
| | - Fuming Mei
- School of Chemistry and Chemical Engineering, Key laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, PR China.
| | - Zhuqi Chen
- School of Chemistry and Chemical Engineering, Key laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, PR China.
| | - Guochuan Yin
- School of Chemistry and Chemical Engineering, Key laboratory of Material Chemistry for Energy Conversion and Storage (Huazhong University of Science and Technology), Ministry of Education, Hubei Key Laboratory of Material Chemistry and Service Failure, Huazhong University of Science and Technology, Wuhan 430074, PR China.
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24
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Effect of Brшnsted Acid on the Reactivity and Selectivity of the Oxoiron(V) Intermediates in C-H and C=C Oxidation Reactions. Catalysts 2022. [DOI: 10.3390/catal12090949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The effect of HClO4 on the reactivity and selectivity of the catalyst systems 1,2/H2O2/AcOH, based on nonheme iron complexes of the PDP families, [(Me2OMePDP)FeIII(μ-OH)2FeIII(MeOMe2PDP)](OTf)4 (1) and [(NMe2PDP)FeIII(μ-OH)2FeIII(NMe2PDP](OTf)4 (2), toward oxidation of benzylideneacetone (bna), adamantane (ada), and (3aR)-(+)-sclareolide (S) has been studied. Adding HClO4 (2–10 equiv. vs. Fe) has been found to result in the simultaneous improvement of the observed catalytic efficiency (i.e., product yields) and the oxidation regio- or enantioselectivity. At the same time, HClO4 causes a threefold increase of the second-order rate constant for the reaction of the key oxygen-transferring intermediate [(Me2OMePDP)FeV=O(OAc)]2+ (1a), with cyclohexane at −70 °C. The effect of strong Brønsted acid on the catalytic reactivity is discussed in terms of the reversible protonation of the Fe=O moiety of the parent perferryl intermediates.
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25
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Cutsail GE, Banerjee R, Rice DB, McCubbin Stepanic O, Lipscomb JD, DeBeer S. Determination of the iron(IV) local spin states of the Q intermediate of soluble methane monooxygenase by Kβ X-ray emission spectroscopy. J Biol Inorg Chem 2022; 27:573-582. [PMID: 35988092 PMCID: PMC9470658 DOI: 10.1007/s00775-022-01953-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 08/07/2022] [Indexed: 11/29/2022]
Abstract
Soluble methane monooxygenase (sMMO) facilitates the conversion of methane to methanol at a non-heme FeIV2 intermediate MMOHQ, which is formed in the active site of the sMMO hydroxylase component (MMOH) during the catalytic cycle. Other biological systems also employ high-valent FeIV sites in catalysis; however, MMOHQ is unique as Nature’s only identified FeIV2 intermediate. Previous 57Fe Mössbauer spectroscopic studies have shown that MMOHQ employs antiferromagnetic coupling of the two FeIV sites to yield a diamagnetic cluster. Unfortunately, this lack of net spin prevents the determination of the local spin state (Sloc) of each of the irons by most spectroscopic techniques. Here, we use Fe Kβ X-ray emission spectroscopy (XES) to characterize the local spin states of the key intermediates of the sMMO catalytic cycle, including MMOHQ trapped by rapid-freeze-quench techniques. A pure XES spectrum of MMOHQ is obtained by subtraction of the contributions from other reaction cycle intermediates with the aid of Mössbauer quantification. Comparisons of the MMOHQ spectrum with those of known Sloc = 1 and Sloc = 2 FeIV sites in chemical and biological models reveal that MMOHQ possesses Sloc = 2 iron sites. This experimental determination of the local spin state will help guide future computational and mechanistic studies of sMMO catalysis.
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Affiliation(s)
- George E Cutsail
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany.
- Institute of Inorganic Chemistry, University of Duisburg-Essen, Universitätsstrasse 5-7, 45117, Essen, Germany.
| | - Rahul Banerjee
- Department of Biochemistry Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Derek B Rice
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany
| | - Olivia McCubbin Stepanic
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany
| | - John D Lipscomb
- Department of Biochemistry Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470, Mülheim an der Ruhr, Germany.
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26
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Nandy A, Adamji H, Kastner DW, Vennelakanti V, Nazemi A, Liu M, Kulik HJ. Using Computational Chemistry To Reveal Nature’s Blueprints for Single-Site Catalysis of C–H Activation. ACS Catal 2022. [DOI: 10.1021/acscatal.2c02096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Aditya Nandy
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Husain Adamji
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - David W. Kastner
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Vyshnavi Vennelakanti
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Azadeh Nazemi
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Mingjie Liu
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Heather J. Kulik
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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27
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Dedushko MA, Greiner MB, Downing AN, Coggins M, Kovacs JA. Electronic Structure and Reactivity of Dioxygen-Derived Aliphatic Thiolate-Ligated Fe-Peroxo and Fe(IV) Oxo Compounds. J Am Chem Soc 2022; 144:8515-8528. [PMID: 35522532 DOI: 10.1021/jacs.1c07656] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Herein, we examine the electronic and geometric structural properties of O2-derived aliphatic thiolate-ligated Fe-peroxo, Fe-hydroxo, and Fe(IV) oxo compounds. The latter cleaves strong C-H bonds (96 kcal mol-1) on par with the valine C-H bond cleaved by isopencillin N synthase (IPNS). Stopped-flow kinetics studies indicate that the barrier to O2 binding to [FeII(SMe2N4(tren))]+ (3) is extremely low (Ea = 36(2) kJ mol-1), as theoretically predicted for IPNS. Dioxygen binding to 3 is shown to be reversible, and a superoxo intermediate, [FeIII(SMe2N4(tren))(O2)]+ (6), forms in the first 25 ms of the reaction at -40 °C prior to the rate-determining (Ea = 46(2) kJ mol-1) formation of peroxo-bridged [(SMe2N4(tren))Fe(III)]2(μ-O2)2+ (7). A log(kobs) vs log([Fe]) plot for the formation of 7 is consistent with the second-order dependence on iron, and H2O2 assays are consistent with a 2:1 ratio of Fe/H2O2. Peroxo 7 is shown to convert to ferric-hydroxo [FeIII(SMe2N(tren))(OH)]+ (9, g⊥ = 2.24, g∥ = 1.96), the identity of which was determined via its independent synthesis. Rates of the conversion 7 → 9 are shown to be dependent on the X-H bond strength of the H-atom donor, with a kH/kD = 4 when CD3OD is used in place of CH3OH as a solvent. A crystallographically characterized cis thiolate-ligated high-valent iron oxo, [FeIV(O)(SMe2N4(tren))]+ (11), is shown to form en route to hydroxo 9. Electronic structure calculations were shown to be consistent with 11 being an S = 1 Fe(IV)═O with an unusually high νFe-O stretching frequency at 918 cm-1 in line with the extremely short Fe-O bond (1.603(7) Å).
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Affiliation(s)
- Maksym A Dedushko
- Department of Chemistry, University of Washington, Campus Box 351700, Seattle, Washington 98195-1700, United States
| | - Maria B Greiner
- Department of Chemistry, University of Washington, Campus Box 351700, Seattle, Washington 98195-1700, United States
| | - Alexandra N Downing
- Department of Chemistry, University of Washington, Campus Box 351700, Seattle, Washington 98195-1700, United States
| | - Michael Coggins
- Department of Chemistry, University of Washington, Campus Box 351700, Seattle, Washington 98195-1700, United States
| | - Julie A Kovacs
- Department of Chemistry, University of Washington, Campus Box 351700, Seattle, Washington 98195-1700, United States
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28
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Morimoto Y, Itoh S. Hydroxylation of Aliphatic and Aromatic C-H Bonds Catalyzed by Biomimetic Transition-metal Complexes. J SYN ORG CHEM JPN 2022. [DOI: 10.5059/yukigoseikyokaishi.80.506] [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)
| | - Shinobu Itoh
- Graduate School of Engineering, Osaka University
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29
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Monika, Ansari A. Effect of the ring size of TMC ligands in controlling C-H bond activation by metal-superoxo species. Dalton Trans 2022; 51:5878-5889. [PMID: 35347335 DOI: 10.1039/d2dt00491g] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Metal-superoxo species play a very important role in many metal-mediated catalytic transformation reactions. Their catalytic reactivity is affected by many factors such as the nature of metal ions and ring size of ligands. Herein, for the first time, we report DFT calculations on the electronic structures of a series of metal-superoxo species (M = V, Cr, Mn, Fe, and Co) with two ring size ligands, i.e., 13-TMC/14-TMC, and a detailed mechanistic study on the C-H bond activation of cyclohexa-1,4-diene followed by the effect of the ring size of ligands. Our DFT results showed that the electron density at the distal oxygen plays an important role in C-H bond activation. By computing the energetics of C-H bond activation and mapping the potential energy surface, it was found that the initial hydrogen abstraction is the rate-determining step with both TMC rings and all the studied metal-superoxo species. The significant electron density at the cyclohex-1,4-diene carbon indicates that the reaction proceeds via the proton-coupled electron transfer mechanism. By mapping the potential energy surfaces, we found that the 13-TMC ligated superoxo with the anti-isomer are more reactive than the 14-TMC superoxo species except for the iron-superoxo species where the 14-TMC ligated superoxo species is more reactive i.e. smaller ring size TMC is more reactive towards C-H bond activation. This is also supported by the structural correlation, i.e., the greater contraction in the smaller ring results in the metal being pushed out of plane along the z-axis, which reduces the steric hindrance. Thus, the ring size can help in designing catalysts with better efficiency for catalytic reactions.
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Affiliation(s)
- Monika
- Department of Chemistry, Central University of Haryana, India, 123031.
| | - Azaj Ansari
- Department of Chemistry, Central University of Haryana, India, 123031.
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30
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Tao Y, Li Z, Zhang Y, Sun K, Liu Z. Determining the inherent selectivity for carbon radical hydroxylation versus halogenation with high-spin oxoiron(iv)-halide complexes: a concerted rebound step. RSC Adv 2022; 12:9891-9897. [PMID: 35424943 PMCID: PMC8963258 DOI: 10.1039/d2ra01384c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 03/22/2022] [Indexed: 11/23/2022] Open
Abstract
A synthetic iron model can process both halogenation and hydroxylation with vague selectivity, which is different from halogenase even though these structures are used for the simulation of halogenase. The key factor of the synthetic oxo-iron model mediated hydroxylation or the halogenation is still under debate. Herein density functional theory calculation is used to investigate the hydroxylation versus halogenation of propylene by the complex [FeIV(O)(TQA)(X)]+ (X = F, Cl, Br). Our results suggest that a concerted rebound mechanism (between the -X and the hydroxyl ligands after the hydrogen abstraction) leads to the formation of two different kinds of products. DFT calculation for the hydroxylation versus halogenation of propylene by [FeIV(O)(TQA)X]+ (X = F, Cl and Br) reveals that after hydrogen abstraction, halogen and oxygen rebound reactions are a synergistic process.![]()
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Affiliation(s)
- Yaping Tao
- College of Physics and Electronic Information & Henan Key Laboratory of Electromagnetic Transformation and Detection, Luoyang Normal University Luoyang 471934 China
| | - Zixian Li
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology Beijing 100029 China
| | - Yiman Zhang
- College of Physics and Electronic Information & Henan Key Laboratory of Electromagnetic Transformation and Detection, Luoyang Normal University Luoyang 471934 China
| | - Kexi Sun
- College of Physics and Electronic Information & Henan Key Laboratory of Electromagnetic Transformation and Detection, Luoyang Normal University Luoyang 471934 China
| | - Zhaojun Liu
- College of Physics and Electronic Information & Henan Key Laboratory of Electromagnetic Transformation and Detection, Luoyang Normal University Luoyang 471934 China
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31
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Munshi S, Sinha A, Yiga S, Banerjee S, Singh R, Hossain MK, Haukka M, Valiati AF, Huelsmann RD, Martendal E, Peralta R, Xavier F, Wendt OF, Paine TK, Nordlander E. Hydrogen-atom and oxygen-atom transfer reactivities of iron(IV)-oxo complexes of quinoline-substituted pentadentate ligands. Dalton Trans 2022; 51:870-884. [PMID: 34994361 DOI: 10.1039/d1dt03381f] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A series of iron(II) complexes with the general formula [FeII(L2-Qn)(L)]n+ (n = 1, L = F-, Cl-; n = 2, L = NCMe, H2O) have been isolated and characterized. The X-ray crystallographic data reveals that metal-ligand bond distances vary with varying ligand field strengths of the sixth ligand. While the complexes with fluoride, chloride and water as axial ligand are high spin, the acetonitrile-coordinated complex is in a mixed spin state. The steric bulk of the quinoline moieties forces the axial ligands to deviate from the Fe-Naxial axis. A higher deviation/tilt is noted for the high spin complexes, while the acetonitrile coordinated complex displays least deviation. This deviation from linearity is slightly less in the analogous low-spin iron(II) complex [FeII(L1-Qn)(NCMe)]2+ of the related asymmetric ligand L1-Qn due to the presence of only one sterically demanding quinoline moiety. The two iron(II)-acetonitrile complexes [FeII(L2-Qn)(NCMe)]2+ and [FeII(L1-Qn)(NCMe)]2+ generate the corresponding iron(IV)-oxo species with higher thermal stability of the species supported by the L1-Qn ligand. The crystallographic and spectroscopic data for [FeIV(O)(L1-Qn)](ClO4)2 bear resemblance to other crystallographically characterized S = 1 iron(IV)-oxo complexes. The hydrogen atom transfer (HAT) and oxygen atom transfer (OAT) reactivities of both the iron(IV)-oxo complexes were investigated, and a Box-Behnken multivariate optimization of the parameters for catalytic oxidation of cyclohexane by [FeII(L2-Qn)(NCMe)]2+ using hydrogen peroxide as the terminal oxidant is presented. An increase in the average Fe-N bond length in [FeII(L1-Qn)(NCMe)]2+ is also manifested in higher HAT and OAT rates relative to the other reported complexes of ligands based on the N4Py framework. The results reported here confirm that the steric influence of the ligand environment is of critical importance for the reactivity of iron(IV)-oxo complexes, but additional electronic factors must influence the reactivity of iron-oxo complexes of N4Py derivatives.
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Affiliation(s)
- Sandip Munshi
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata, India.
| | - Arup Sinha
- Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-221 00 Lund, Sweden. .,Department of Chemistry, School of Advanced Science, Vellore Institute of Technology, Vellore, India
| | - Solomon Yiga
- Center for Analysis and Synthesis, Department of Chemistry, Lund University, Box 124, SE-221 00 Lund, Sweden. .,Department of Chemistry, Makerere University, P. O. Box 7062, Kampala, Uganda
| | - Sridhar Banerjee
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata, India.
| | - Reena Singh
- Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-221 00 Lund, Sweden.
| | - Md Kamal Hossain
- Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-221 00 Lund, Sweden.
| | - Matti Haukka
- Department of Chemistry, University of Jyväskylä, Box 35, FI-400 14, Jyväskylä, Finland
| | - Andrei Felipe Valiati
- Department of Chemistry, LABINC, Universidade Federal de Santa Catarina (UFSC), 88040-900 Florianopolis, Santa Catarina, Brazil
| | - Ricardo Dagnoni Huelsmann
- Department of Chemistry, Center for Technological Sciences, Universidade do Estado de Santa Catarina (UDESC), 89219-710 Joinville, Santa Catarina, Brazil
| | - Edmar Martendal
- Department of Chemistry, Center for Technological Sciences, Universidade do Estado de Santa Catarina (UDESC), 89219-710 Joinville, Santa Catarina, Brazil
| | - Rosely Peralta
- Department of Chemistry, LABINC, Universidade Federal de Santa Catarina (UFSC), 88040-900 Florianopolis, Santa Catarina, Brazil
| | - Fernando Xavier
- Department of Chemistry, Center for Technological Sciences, Universidade do Estado de Santa Catarina (UDESC), 89219-710 Joinville, Santa Catarina, Brazil
| | - Ola F Wendt
- Center for Analysis and Synthesis, Department of Chemistry, Lund University, Box 124, SE-221 00 Lund, Sweden.
| | - Tapan K Paine
- School of Chemical Sciences, Indian Association for the Cultivation of Science, Kolkata, India.
| | - Ebbe Nordlander
- Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-221 00 Lund, Sweden.
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32
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Gupta R, Li XX, Lee Y, Seo MS, Lee YM, Yanagisawa S, Kubo M, Sarangi R, Cho KB, Fukuzumi S, Nam W. Heme compound II models in chemoselectivity and disproportionation reactions. Chem Sci 2022; 13:5707-5717. [PMID: 35694346 PMCID: PMC9116367 DOI: 10.1039/d2sc01232d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 04/11/2022] [Indexed: 11/23/2022] Open
Abstract
Heme compound II models bearing electron-deficient and -rich porphyrins, [FeIV(O)(TPFPP)(Cl)]− (1a) and [FeIV(O)(TMP)(Cl)]− (2a), respectively, are synthesized, spectroscopically characterized, and investigated in chemoselectivity and disproportionation reactions using cyclohexene as a mechanistic probe. Interestingly, cyclohexene oxidation by 1a occurs at the allylic C–H bonds with a high kinetic isotope effect (KIE) of 41, yielding 2-cyclohexen-1-ol product; this chemoselectivity is the same as that of nonheme iron(iv)-oxo intermediates. In contrast, as observed in heme compound I models, 2a yields cyclohexene oxide product with a KIE of 1, demonstrating a preference for C
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C epoxidation. The latter result is interpreted as 2a disproportionating to form [FeIV(O)(TMP+˙)]+ (2b) and FeIII(OH)(TMP), and 2b becoming the active oxidant to conduct the cyclohexene epoxidation. In contrast to 2a, 1a does not disproportionate under the present reaction conditions. DFT calculations confirm that compound II models prefer C–H bond hydroxylation and that disproportionation of compound II models is controlled thermodynamically by the porphyrin ligands. Other aspects, such as acid and base effects on the disproportionation of compound II models, have been discussed as well. Disproportionation of Cpd II models depends on the electron-richness of the porphyrin ligand; Cpd II with an electron-deficient ligand is difficult to disproportionate, whereas Cpd II with an electron-rich ligand readily disproportionates to form Cpd I as a true oxidant.![]()
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Affiliation(s)
- Ranjana Gupta
- 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
| | - Youngseob Lee
- Department of Chemistry, Jeonbuk National University Jeonju 54896 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
| | - Sachiko Yanagisawa
- Graduate School of Life Science, University of Hyogo Hyogo 678-1297 Japan
| | - Minoru Kubo
- Graduate School of Life Science, University of Hyogo Hyogo 678-1297 Japan
| | - Ritimukta Sarangi
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University California 94023 USA
| | - 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
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University Seoul 03760 Korea
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33
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Mandal D, Katoch A. Effect of Substituent on C-H Activation Catalysed by a nonheme Fe(IV)O Complex: A Computational Investigation of Reactivity and Hydrogen Tunneling. Dalton Trans 2022; 51:11641-11649. [DOI: 10.1039/d2dt01529c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A density functional theory investigation has been presented here to address the C-H activation reactivity and the influence of quantum mechanical tunneling catalyzed by a non-heme iron(IV)-Oxo complex viz. [FeIVOdpaq-X]+...
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34
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Gordon JB, Albert T, Dey A, Sabuncu S, Siegler MA, Bill E, Moënne-Loccoz P, Goldberg DP. A Reactive, Photogenerated High-Spin ( S = 2) Fe IV(O) Complex via O 2 Activation. J Am Chem Soc 2021; 143:21637-21647. [PMID: 34913683 PMCID: PMC9109941 DOI: 10.1021/jacs.1c10051] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Addition of dioxygen at low temperature to the non-heme ferrous complex FeII(Me3TACN)((OSiPh2)2O) (1) in 2-MeTHF produces a peroxo-bridged diferric complex Fe2III(μ-O2)(Me3TACN)2((OSiPh2)2O)2 (2), which was characterized by UV-vis, resonance Raman, and variable field Mössbauer spectroscopies. Illumination of a frozen solution of 2 in THF with white light leads to homolytic O-O bond cleavage and generation of a FeIV(O) complex 4 (ν(Fe=O) = 818 cm-1; δ = 0.22 mm s-1, ΔEQ = 0.23 mm s-1). Variable field Mössbauer spectroscopy measurements show that 4 is a rare example of a high-spin S = 2 FeIV(O) complex and the first synthetic example to be generated directly from O2. Complex 4 is highly reactive, as expected for a high-spin ferryl, and decays rapidly in fluid solution at cryogenic temperatures. This decay process in 2-MeTHF involves C-H cleavage of the solvent. However, the controlled photolysis of 2 in situ with visible light and excess phenol substrate leads to competitive phenol oxidation, via the proposed transient generation of 4 as the active oxidant.
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Affiliation(s)
- Jesse B. Gordon
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
| | - Therese Albert
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Aniruddha Dey
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
| | - Sinan Sabuncu
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Maxime A. Siegler
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA
| | - Eckhard Bill
- Department of Inorganic Spectroscopy / Joint Workspace, Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34−36, 45470 Mülheim-an-der-Ruhr, Germany,Corresponding Author: , ,
| | - Pierre Moënne-Loccoz
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, Oregon 97239, USA,Corresponding Author: , ,
| | - David P. Goldberg
- Department of Chemistry, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218, USA,Corresponding Author: , ,
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35
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Kumar R, Sundararajan M, Rajaraman G. A six-coordinate high-spin Fe IVO species of cucurbit[5]uril: a highly potent catalyst for C-H hydroxylation of methane, if synthesised. Chem Commun (Camb) 2021; 57:13760-13763. [PMID: 34854853 DOI: 10.1039/d1cc06391j] [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
DFT and ab initio DLPNO-CCSD(T) calculations predict a stable S = 2 six-coordinate FeIVO species with cucurbit[5]uril (CB[5]) as a ligand ([(CB[5])FeIVO(H2O)]2+(1)). The strong oxidising capability of 1 far exceeds even that of metalloenzymes such as sMMOs in activating inert substrates such as methane, setting the stage for a new generation of biomimetic catalysts.
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Affiliation(s)
- Ravi Kumar
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
| | - Mahesh Sundararajan
- Theoretical Chemistry Section, Chemistry Division, Bhabha Atomic Research Centre, Mumbai-400085, India.
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
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36
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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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37
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Guo M, Zhang J, Zhang L, Lee YM, Fukuzumi S, Nam W. Enthalpy-Entropy Compensation Effect in Oxidation Reactions by Manganese(IV)-Oxo Porphyrins and Nonheme Iron(IV)-Oxo Models. J Am Chem Soc 2021; 143:18559-18570. [PMID: 34723505 DOI: 10.1021/jacs.1c08198] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
"Enthalpy-Entropy Compensation Effect" (EECE) is ubiquitous in chemical reactions; however, such an EECE has been rarely explored in biomimetic oxidation reactions. In this study, six manganese(IV)-oxo complexes bearing electron-rich and -deficient porphyrins are synthesized and investigated in various oxidation reactions, such as hydrogen atom transfer (HAT), oxygen atom transfer (OAT), and electron-transfer (ET) reactions. First, all of the six Mn(IV)-oxo porphyrins are highly reactive in the HAT, OAT, and ET reactions. Interestingly, we have observed a reversed reactivity in the HAT and OAT reactions by the electron-rich and -deficient Mn(IV)-oxo porphyrins, depending on reaction temperatures, but not in the ET reactions; the electron-rich Mn(IV)-oxo porphyrins are more reactive than the electron-deficient Mn(IV)-oxo porphyrins at high temperature (e.g., 0 °C), whereas at low temperature (e.g., -60 °C), the electron-deficient Mn(IV)-oxo porphyrins are more reactive than the electron-rich Mn(IV)-oxo porphyrins. Such a reversed reactivity between the electron-rich and -deficient Mn(IV)-oxo porphyrins depending on reaction temperatures is rationalized with EECE; that is, the lower is the activation enthalpy, the more negative is the activation entropy, and vice versa. Interestingly, a unified linear correlation between the activation enthalpies and the activation entropies is observed in the HAT and OAT reactions of the Mn(IV)-oxo porphyrins. Moreover, from the previously reported HAT reactions of nonheme Fe(IV)-oxo complexes, a linear correlation between the activation enthalpies and the activation entropies is also observed. To the best of our knowledge, we report the first detailed mechanistic study of EECE in the oxidation reactions by synthetic high-valent metal-oxo complexes.
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Affiliation(s)
- Mian Guo
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea.,College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China
| | - Jisheng Zhang
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea
| | - Lina Zhang
- 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
| | - 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
| | - 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, PR China
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38
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Heim P, Twamley B, O'Brien J, McDonald AR. Unexpected Intramolecular Phosphite‐Mediated Amide Coupling To Yield 3,5‐Dioxo‐1‐Piperazines. ChemistrySelect 2021. [DOI: 10.1002/slct.202102576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Philipp Heim
- School of Chemistry and CRANN/AMBER Nanoscience Institute Trinity College Dublin The University of Dublin College Green Dublin 2 Ireland
| | - Brendan Twamley
- School of Chemistry and CRANN/AMBER Nanoscience Institute Trinity College Dublin The University of Dublin College Green Dublin 2 Ireland
| | - John O'Brien
- School of Chemistry and CRANN/AMBER Nanoscience Institute Trinity College Dublin The University of Dublin College Green Dublin 2 Ireland
| | - 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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39
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Opalade AA, Hessefort L, Day VW, Jackson TA. Controlling the Reactivity of a Metal-Hydroxo Adduct with a Hydrogen Bond. J Am Chem Soc 2021; 143:15159-15175. [PMID: 34494835 DOI: 10.1021/jacs.1c06199] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The enzymes manganese lipoxygenase (MnLOX) and manganese superoxide dismutase (MnSOD) utilize mononuclear Mn centers to effect their catalytic reactions. In the oxidized MnIII state, the active site of each enzyme contains a hydroxo ligand, and X-ray crystal structures imply a hydrogen bond between this hydroxo ligand and a cis carboxylate ligand. While hydrogen bonding is a common feature of enzyme active sites, the importance of this particular hydroxo-carboxylate interaction is relatively unexplored. In this present study, we examined a pair of MnIII-hydroxo complexes that differ by a single functional group. One of these complexes, [MnIII(OH)(PaPy2N)]+, contains a naphthyridinyl moiety capable of forming an intramolecular hydrogen bond with the hydroxo ligand. The second complex, [MnIII(OH)(PaPy2Q)]+, contains a quinolinyl moiety that does not permit any intramolecular hydrogen bonding. Spectroscopic characterization of these complexes supports a common structure, but with perturbations to [MnIII(OH)(PaPy2N)]+, consistent with a hydrogen bond. Kinetic studies using a variety of substrates with activated O-H bonds, revealed that [MnIII(OH)(PaPy2N)]+ is far more reactive than [MnIII(OH)(PaPy2Q)]+, with rate enhancements of 15-100-fold. A detailed analysis of the thermodynamic contributions to these reactions using DFT computations reveals that the former complex is significantly more basic. This increased basicity counteracts the more negative reduction potential of this complex, leading to a stronger O-H BDFE in the [MnII(OH2)(PaPy2N)]+ product. Thus, the differences in reactivity between [MnIII(OH)(PaPy2Q)]+ and [MnIII(OH)(PaPy2N)]+ can be understood on the basis of thermodynamic considerations, which are strongly influenced by the ability of the latter complex to form an intramolecular hydrogen bond.
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Affiliation(s)
- Adedamola A Opalade
- The University of Kansas, Department of Chemistry and Center for Environmentally Beneficial Catalysis, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Logan Hessefort
- The University of Kansas, Department of Chemistry and Center for Environmentally Beneficial Catalysis, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Victor W Day
- The University of Kansas, Department of Chemistry and Center for Environmentally Beneficial Catalysis, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
| | - Timothy A Jackson
- The University of Kansas, Department of Chemistry and Center for Environmentally Beneficial Catalysis, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States
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40
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Lee JL, Ross DL, Barman SK, Ziller JW, Borovik AS. C-H Bond Cleavage by Bioinspired Nonheme Metal Complexes. Inorg Chem 2021; 60:13759-13783. [PMID: 34491738 DOI: 10.1021/acs.inorgchem.1c01754] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The functionalization of C-H bonds is one of the most challenging transformations in synthetic chemistry. In biology, these processes are well-known and are achieved with a variety of metalloenzymes, many of which contain a single metal center within their active sites. The most well studied are those with Fe centers, and the emerging experimental data show that high-valent iron oxido species are the intermediates responsible for cleaving the C-H bond. This Forum Article describes the state of this field with an emphasis on nonheme Fe enzymes and current experimental results that provide insights into the properties that make these species capable of C-H bond cleavage. These parameters are also briefly considered in regard to manganese oxido complexes and Cu-containing metalloenzymes. Synthetic iron oxido complexes are discussed to highlight their utility as spectroscopic and mechanistic probes and reagents for C-H bond functionalization. Avenues for future research are also examined.
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Affiliation(s)
- Justin L Lee
- Department of Chemistry, University of California-Irvine, 1102 Natural Sciences II, Irvine, California 92697, United States
| | - Dolores L Ross
- Department of Chemistry, University of California-Irvine, 1102 Natural Sciences II, Irvine, California 92697, United States
| | - Suman K Barman
- Department of Chemistry, University of California-Irvine, 1102 Natural Sciences II, Irvine, California 92697, United States
| | - Joseph W Ziller
- Department of Chemistry, University of California-Irvine, 1102 Natural Sciences II, Irvine, California 92697, United States
| | - A S Borovik
- Department of Chemistry, University of California-Irvine, 1102 Natural Sciences II, Irvine, California 92697, United States
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41
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Chandra A, Ansari M, Monte‐Pérez I, Kundu S, Rajaraman G, Ray K. Ligand‐Constraint‐Induced Peroxide Activation for Electrophilic Reactivity. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202100438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Anirban Chandra
- Department of Chemistry Humboldt-Universität zu Berlin Brook-Taylor-Strasse 2 12489 Berlin Germany
| | - Mursaleem Ansari
- Department of Chemistry Indian Institute of Technology Bombay, Powai Mumbai Maharashtra 400 076 India
| | - Inés Monte‐Pérez
- Department of Chemistry Humboldt-Universität zu Berlin Brook-Taylor-Strasse 2 12489 Berlin Germany
| | - Subrata Kundu
- Department of Chemistry Humboldt-Universität zu Berlin Brook-Taylor-Strasse 2 12489 Berlin Germany
| | - Gopalan Rajaraman
- Department of Chemistry Indian Institute of Technology Bombay, Powai Mumbai Maharashtra 400 076 India
| | - Kallol Ray
- Department of Chemistry Humboldt-Universität zu Berlin Brook-Taylor-Strasse 2 12489 Berlin Germany
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42
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Chandra A, Ansari M, Monte-Pérez I, Kundu S, Rajaraman G, Ray K. Ligand-Constraint-Induced Peroxide Activation for Electrophilic Reactivity. Angew Chem Int Ed Engl 2021; 60:14954-14959. [PMID: 33843113 PMCID: PMC8252416 DOI: 10.1002/anie.202100438] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 03/26/2021] [Indexed: 12/16/2022]
Abstract
μ‐1,2‐peroxo‐bridged diiron(III) intermediates P are proposed as reactive intermediates in various biological oxidation reactions. In sMMO, P acts as an electrophile, and performs hydrogen atom and oxygen atom transfers to electron‐rich substrates. In cyanobacterial ADO, however, P is postulated to react by nucleophilic attack on electrophilic carbon atoms. In biomimetic studies, the ability of μ‐1,2‐peroxo‐bridged dimetal complexes of Fe, Co, Ni and Cu to act as nucleophiles that effect deformylation of aldehydes is documented. By performing reactivity and theoretical studies on an end‐on μ‐1,2‐peroxodicobalt(III) complex 1 involving a non‐heme ligand system, L1, supported on a Sn6O6 stannoxane core, we now show that a peroxo‐bridged dimetal complex can also be a reactive electrophile. The observed electrophilic chemistry, which is induced by the constraints provided by the Sn6O6 core, represents a new domain for metal−peroxide reactivity.
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Affiliation(s)
- Anirban Chandra
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Strasse 2, 12489, Berlin, Germany
| | - Mursaleem Ansari
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, 400 076, India
| | - Inés Monte-Pérez
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Strasse 2, 12489, Berlin, Germany
| | - Subrata Kundu
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Strasse 2, 12489, Berlin, Germany
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, 400 076, India
| | - Kallol Ray
- Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Strasse 2, 12489, Berlin, Germany
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43
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Biswas JP, Ansari M, Paik A, Sasmal S, Paul S, Rana S, Rajaraman G, Maiti D. Effect of the Ligand Backbone on the Reactivity and Mechanistic Paradigm of Non‐Heme Iron(IV)‐Oxo during Olefin Epoxidation. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202102484] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Jyoti Prasad Biswas
- Department of Chemistry Indian Institute of Technology Bombay Powai Mumbai 400076 India
| | - Mursaleem Ansari
- Department of Chemistry Indian Institute of Technology Bombay Powai Mumbai 400076 India
| | - Aniruddha Paik
- Department of Chemistry University of North Bengal Raja Rammohunpur Darjeeling West Bengal, Pin 734013 India
| | - Sheuli Sasmal
- Department of Chemistry Indian Institute of Technology Bombay Powai Mumbai 400076 India
| | - Sabarni Paul
- Department of Chemistry University of North Bengal Raja Rammohunpur Darjeeling West Bengal, Pin 734013 India
| | - Sujoy Rana
- Department of Chemistry University of North Bengal Raja Rammohunpur Darjeeling West Bengal, Pin 734013 India
| | - Gopalan Rajaraman
- Department of Chemistry Indian Institute of Technology Bombay Powai Mumbai 400076 India
| | - Debabrata Maiti
- Department of Chemistry Indian Institute of Technology Bombay Powai Mumbai 400076 India
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44
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Zhang H, Su X, Xie F, Liao R, Zhang M. Iron‐Catalyzed Water Oxidation: O–O Bond Formation via Intramolecular Oxo–Oxo Interaction. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202100060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Hong‐Tao Zhang
- Center of Basic Molecular Science (CBMS) Department of Chemistry Tsinghua University Beijing 100084 China
| | - Xiao‐Jun Su
- Center of Basic Molecular Science (CBMS) Department of Chemistry Tsinghua University Beijing 100084 China
| | - Fei Xie
- Center of Basic Molecular Science (CBMS) Department of Chemistry Tsinghua University Beijing 100084 China
| | - Rong‐Zhen Liao
- Key Laboratory for Large-Format Battery Materials and System School of Chemistry and Chemical Engineering Huazhong University of Science and Technology Wuhan 430074 China
| | - Ming‐Tian Zhang
- Center of Basic Molecular Science (CBMS) Department of Chemistry Tsinghua University Beijing 100084 China
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45
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Zhang HT, Su XJ, Xie F, Liao RZ, Zhang MT. Iron-Catalyzed Water Oxidation: O-O Bond Formation via Intramolecular Oxo-Oxo Interaction. Angew Chem Int Ed Engl 2021; 60:12467-12474. [PMID: 33769654 DOI: 10.1002/anie.202100060] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Indexed: 12/30/2022]
Abstract
Herein, we report the importance of structure regulation on the O-O bond formation process in binuclear iron catalysts. Three complexes, [Fe2 (μ-O)(OH2 )2 (TPA)2 ]4+ (1), [Fe2 (μ-O)(OH2 )2 (6-HPA)]4+ (2) and [Fe2 (μ-O)(OH2 )2 (BPMAN)]4+ (3), have been designed as electrocatalysts for water oxidation in 0.1 M NaHCO3 solution (pH 8.4). We found that 1 and 2 are molecular catalysts and that O-O bond formation proceeds via oxo-oxo coupling rather than by the water nucleophilic attack (WNA) pathway. In contrast, complex 3 displays negligible catalytic activity. DFT calculations suggested that the anti to syn isomerization of the two high-valent Fe=O moieties in these catalysts takes place via the axial rotation of one Fe=O unit around the Fe-O-Fe center. This is followed by the O-O bond formation via an oxo-oxo coupling pathway at the FeIV FeIV state or via oxo-oxyl coupling pathway at the FeIV FeV state. Importantly, the rigid BPMAN ligand in complex 3 limits the anti to syn isomerization and axial rotation of the Fe=O moiety, which accounts for the negligible catalytic activity.
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Affiliation(s)
- Hong-Tao Zhang
- Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Xiao-Jun Su
- Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Fei Xie
- Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University, Beijing, 100084, China
| | - Rong-Zhen Liao
- Key Laboratory for Large-Format Battery Materials and System, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Ming-Tian Zhang
- Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University, Beijing, 100084, China
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46
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Biswas JP, Ansari M, Paik A, Sasmal S, Paul S, Rana S, Rajaraman G, Maiti D. Effect of the Ligand Backbone on the Reactivity and Mechanistic Paradigm of Non-Heme Iron(IV)-Oxo during Olefin Epoxidation. Angew Chem Int Ed Engl 2021; 60:14030-14039. [PMID: 33836110 DOI: 10.1002/anie.202102484] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Indexed: 01/08/2023]
Abstract
The oxygen atom transfer (OAT) reactivity of the non-heme [FeIV (2PyN2Q)(O)]2+ (2) containing the sterically bulky quinoline-pyridine pentadentate ligand (2PyN2Q) has been thoroughly studied with different olefins. The ferryl-oxo complex 2 shows excellent OAT reactivity during epoxidations. The steric encumbrance and electronic effect of the ligand influence the mechanistic shuttle between OAT pathway I and isomerization pathway II (during the reaction stereo pure olefins), resulting in a mixture of cis-trans epoxide products. In contrast, the sterically less hindered and electronically different [FeIV (N4Py)(O)]2+ (1) provides only cis-stilbene epoxide. A Hammett study suggests the role of dominant inductive electronic along with minor resonance effect during electron transfer from olefin to 2 in the rate-limiting step. Additionally, a computational study supports the involvement of stepwise pathways during olefin epoxidation. The ferryl bend due to the bulkier ligand incorporation leads to destabilization of both d z 2 and d x 2 - y 2 orbitals, leading to a very small quintet-triplet gap and enhanced reactivity for 2 compared to 1. Thus, the present study unveils the role of steric and electronic effects of the ligand towards mechanistic modification during olefin epoxidation.
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Affiliation(s)
- Jyoti Prasad Biswas
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Mursaleem Ansari
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Aniruddha Paik
- Department of Chemistry, University of North Bengal, Raja Rammohunpur, Darjeeling, West Bengal, Pin, 734013, India
| | - Sheuli Sasmal
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Sabarni Paul
- Department of Chemistry, University of North Bengal, Raja Rammohunpur, Darjeeling, West Bengal, Pin, 734013, India
| | - Sujoy Rana
- Department of Chemistry, University of North Bengal, Raja Rammohunpur, Darjeeling, West Bengal, Pin, 734013, India
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Debabrata Maiti
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
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47
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Kulmaczewski R, Howard MJ, Halcrow MA. Influence of ligand substituent conformation on the spin state of an iron(II)/di(pyrazol-1-yl)pyridine complex. Dalton Trans 2021; 50:3464-3467. [PMID: 33660725 DOI: 10.1039/d1dt00590a] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The temperature of the solution-phase spin-crossover equilibrium in iron(ii) complexes of 4-alkylsulfanyl-2,6-di{pyrazol-1-yl}pyridine (bppSR) complexes depends strongly on the alkylsulfanyl substituent. DFT calculations imply this reflects the conformation of the alkylsulfanyl groups, which lie perpendicular to the heterocyclic ligand donors in [Fe(bppStBu)2]2+ but are oriented co-planar with the ligand core for smaller SR substituents.
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Affiliation(s)
- Rafal Kulmaczewski
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, UK LS2 9JT.
| | - Mark J Howard
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, UK LS2 9JT.
| | - Malcolm A Halcrow
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, UK LS2 9JT.
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48
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Warm K, Paskin A, Kuhlmann U, Bill E, Swart M, Haumann M, Dau H, Hildebrandt P, Ray K. A Pseudotetrahedral Terminal Oxoiron(IV) Complex: Mechanistic Promiscuity in C-H Bond Oxidation Reactions. Angew Chem Int Ed Engl 2021; 60:6752-6756. [PMID: 33348460 PMCID: PMC7985879 DOI: 10.1002/anie.202015896] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Indexed: 11/12/2022]
Abstract
S=2 oxoiron(IV) species act as reactive intermediates in the catalytic cycle of nonheme iron oxygenases. The few available synthetic S=2 FeIV =O complexes known to date are often limited to trigonal bipyramidal and very rarely to octahedral geometries. Herein we describe the generation and characterization of an S=2 pseudotetrahedral FeIV =O complex 2 supported by the sterically demanding 1,4,7-tri-tert-butyl-1,4,7-triazacyclononane ligand. Complex 2 is a very potent oxidant in hydrogen atom abstraction (HAA) reactions with large non-classical deuterium kinetic isotope effects, suggesting hydrogen tunneling contributions. For sterically encumbered substrates, direct HAA is impeded and an alternative oxidative asynchronous proton-coupled electron transfer mechanism prevails, which is unique within the nonheme oxoiron community. The high reactivity and the similar spectroscopic parameters make 2 one of the best electronic and functional models for a biological oxoiron(IV) intermediate of taurine dioxygenase (TauD-J).
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Affiliation(s)
- Katrin Warm
- Institut für ChemieHumboldt-Universität zu BerlinBrook-Taylor-Str. 212489BerlinGermany
| | - Alice Paskin
- Institut für ChemieHumboldt-Universität zu BerlinBrook-Taylor-Str. 212489BerlinGermany
| | - Uwe Kuhlmann
- Institut für ChemieTechnische Universität Berlin, Fakultät IIStraße des 17. Juni 13510623BerlinGermany
| | - Eckhard Bill
- Max-Planck-Institut für Chemische Energiekonversion (CEC)Stiftstraße 34–3645470MülheimGermany
| | - Marcel Swart
- Institut de Química Computacional i CatàlisiUniversitat de GironaCampus Montilivi (Ciències)Maria Aurèlia Capmany i Farnés, 6917003GironaSpain
- ICREAPg. Lluís Companys 2308010BarcelonaSpain
| | - Michael Haumann
- Institut für PhysikFreie Universität BerlinArnimallee 1414195BerlinGermany
| | - Holger Dau
- Institut für PhysikFreie Universität BerlinArnimallee 1414195BerlinGermany
| | - Peter Hildebrandt
- Institut für ChemieTechnische Universität Berlin, Fakultät IIStraße des 17. Juni 13510623BerlinGermany
| | - Kallol Ray
- Institut für ChemieHumboldt-Universität zu BerlinBrook-Taylor-Str. 212489BerlinGermany
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49
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Warm K, Paskin A, Kuhlmann U, Bill E, Swart M, Haumann M, Dau H, Hildebrandt P, Ray K. A Pseudotetrahedral Terminal Oxoiron(IV) Complex: Mechanistic Promiscuity in C−H Bond Oxidation Reactions. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202015896] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Katrin Warm
- Institut für Chemie Humboldt-Universität zu Berlin Brook-Taylor-Str. 2 12489 Berlin Germany
| | - Alice Paskin
- Institut für Chemie Humboldt-Universität zu Berlin Brook-Taylor-Str. 2 12489 Berlin Germany
| | - Uwe Kuhlmann
- Institut für Chemie Technische Universität Berlin, Fakultät II Straße des 17. Juni 135 10623 Berlin Germany
| | - Eckhard Bill
- Max-Planck-Institut für Chemische Energiekonversion (CEC) Stiftstraße 34–36 45470 Mülheim Germany
| | - Marcel Swart
- Institut de Química Computacional i Catàlisi Universitat de Girona Campus Montilivi (Ciències) Maria Aurèlia Capmany i Farnés, 69 17003 Girona Spain
- ICREA Pg. Lluís Companys 23 08010 Barcelona Spain
| | - Michael Haumann
- Institut für Physik Freie Universität Berlin Arnimallee 14 14195 Berlin Germany
| | - Holger Dau
- Institut für Physik Freie Universität Berlin Arnimallee 14 14195 Berlin Germany
| | - Peter Hildebrandt
- Institut für Chemie Technische Universität Berlin, Fakultät II Straße des 17. Juni 135 10623 Berlin Germany
| | - Kallol Ray
- Institut für Chemie Humboldt-Universität zu Berlin Brook-Taylor-Str. 2 12489 Berlin Germany
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50
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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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