1
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Katoch A, Mandal D. Impact of carboxylate ligation on the C-H activation reactivity of a non-heme Fe(IV)O complex: a computational investigation. Dalton Trans 2024; 53:15264-15272. [PMID: 39222036 DOI: 10.1039/d4dt02139h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
A comprehensive DFT investigation has been presented to predict how a carboxylate-rich macrocycle would affect the reactivity of a non-heme Fe(IV)O complex towards C-H activation. The popular non-heme iron oxo complex [FeIV(O)(N4Py)]2+, (N4Py = N,N-(bis(2-pyridyl)methyl)N-bis(2-pyridylmethyl)amine) (1), has been selected here as the primary compound. It is transformed to the compound [FeIV(O)(nBu-P2DA)], where nBu-P2DA = N-(1',1'-bis(2-pyridyl)pentyl)iminodiacetate (2) after the replacement of two pyridine donors of N4Py with carboxylate groups. Two other complexes, namely 3 and 4, have been predicted sequentially substituting nitrogen with the carboxylate groups. Ethylbenzene and dihydrotoluene were chosen as substrates. In terms of C-H activation reactivity, an interesting pattern emerges: as the carboxylate group becomes more equatorially enriched, the reactivity increases, following the trend 1 < 2 < 3 < 4. This also aligns with available experimental reports related to complexes 1 and 2. Fe(IV)O complexes exhibit two-state reactivity (triplet and quintet), whereas the quintet state is more favourable due to the stabilization of the transition states through exchange interactions involving a greater number of unpaired electrons. A detailed analysis of the factors influencing reactivity has been performed, including distortion energy (which decreases for the transition state with the addition of carboxylate groups), the triplet-quintet oxidant energy gap (which consistently decreases as carboxylate group enrichment increases), steric factors, and quantum mechanical tunneling. This investigation provides a detailed explanation of the observed outcomes and predicts the higher reactivity of carboxylate-enriched Fe(IV)O complexes. After potential experimental verification, this could lead to the development of new, optimal catalysts for C-H activation.
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Affiliation(s)
- Akanksha Katoch
- Department of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala-147001, Punjab, India.
| | - Debasish Mandal
- Department of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala-147001, Punjab, India.
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2
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Zhang B, Joyce JP, Wolford NJ, Brennessel WW, DeBeer S, Neidig ML. Unusual S=1 Four-Coordinate Fe(IV) Complexes Supported by Bisamide Ligands: Syntheses, Characterization, and Electronic Structures. Angew Chem Int Ed Engl 2024; 63:e202405113. [PMID: 38864588 DOI: 10.1002/anie.202405113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 06/11/2024] [Accepted: 06/12/2024] [Indexed: 06/13/2024]
Abstract
The catalytic relevance of Fe(IV) species in non-heme iron catalysis has motivated synthetic advances in well-defined five- and six-coordinate Fe(IV) complexes for a better understanding of their fundamental electronic structures and reactivities. Herein, we report the syntheses of FeDipp2 and FeMes2, a pair of unusual four-coordinate non-heme formally Fe(IV) complexes with S=1 ground states supported by strongly donating bisamide ligands. By combining spectroscopic characterization and computational modeling, we found that small variations in ligand aryl substituents resulted in substantial changes in both structures and bonding. This work highlights the strong donor capabilities and modularity of the bisamide ligand set. More broadly, it is a critical contribution to the utilization of ligand design to modulate molecular geometries and electronic structures of low-coordinate, high-valent iron complexes.
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Affiliation(s)
- Bufan Zhang
- Department of Chemistry, University of Rochester, Hutchison Hall, 120 Trustee Road, 14627, Rochester, NY, United States
- Department of Inorganic Spectroscopy, Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470, Mülheim an der Ruhr, Germany
| | - Justin P Joyce
- Department of Inorganic Spectroscopy, Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470, Mülheim an der Ruhr, Germany
| | - Nikki J Wolford
- Department of Chemistry, University of Rochester, Hutchison Hall, 120 Trustee Road, 14627, Rochester, NY, United States
| | - William W Brennessel
- Department of Chemistry, University of Rochester, Hutchison Hall, 120 Trustee Road, 14627, Rochester, NY, United States
| | - Serena DeBeer
- Department of Inorganic Spectroscopy, Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470, Mülheim an der Ruhr, Germany
| | - Michael L Neidig
- Department of Chemistry, University of Oxford, Inorganic Chemistry Laboratory, South Parks Road, OX1 3QR, Oxford, United Kingdom
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3
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Török P, Lakk-Bogáth D, Unjaroen D, Browne WR, Kaizer J. Effect of monodentate heterocycle co-ligands on the μ-1,2-peroxo-diiron(III) mediated aldehyde deformylation reactions. J Inorg Biochem 2024; 258:112620. [PMID: 38824901 DOI: 10.1016/j.jinorgbio.2024.112620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 05/17/2024] [Accepted: 05/25/2024] [Indexed: 06/04/2024]
Abstract
Peroxo-diiron(III) species are present in the active sites of many metalloenzymes that carry out challenging organic transformations. The reactivity of these species is influenced by various factors, such as the structure and topology of the supporting ligands, the identity of the axial and equatorial co-ligands, and the oxidation states of the metal ion(s). In this study, we aim to diversify the importance of equatorial ligands in controlling the reactivity of peroxo-diiron(III) species. As a model compound, we chose the previously published and fully characterized [(PBI)2(CH3CN)FeIII(μ-O2)FeIII(CH3CN)(PBI)2]4+ complex, where the steric effect of the four PBI ligands is minimal, so the labile CH3CN molecules easily can be replaced by different monodentate co-ligands (substituted pyridines and N-donor heterocyclic compounds). Thus, their effect on the electronic and spectral properties of peroxo-divas(III) intermediates could be easily investigated. The relationship between structure and reactivity was also investigated in the stoichiometric deformylation of PPA mediated by peroxo-diiron(III) complexes. It was found that the deformylation rates are influenced by the Lewis acidity and redox properties of the metal centers, and showed a linear correlation with the FeIII/FeII redox potentials (in the range of 197 to 415 mV).
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Affiliation(s)
- Patrik Török
- Research Group of Bioorganic and Biocoordination Chemistry, Universtiy of Pannonia, 8201 Veszprém, Hungary
| | - Dóra Lakk-Bogáth
- Research Group of Bioorganic and Biocoordination Chemistry, Universtiy of Pannonia, 8201 Veszprém, Hungary
| | - Duenpen Unjaroen
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - Wesley R Browne
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands.
| | - József Kaizer
- Research Group of Bioorganic and Biocoordination Chemistry, Universtiy of Pannonia, 8201 Veszprém, Hungary.
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4
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Monika, Kumar M, Somi, Sarkar A, Gupta MK, Ansari A. Theoretical study of the formation of metal-oxo species of the first transition series with the ligand 14-TMC: driving factors of the "Oxo Wall". Dalton Trans 2023; 52:14160-14169. [PMID: 37750348 DOI: 10.1039/d3dt02109b] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
Terminal metal-oxo species of the early transition metal series are well known, whereas those for the late transition series are rare, and this is related to the "Oxo Wall". Here, we have undertaken a theoretical study on the formation of metal-oxo species from the metal hydroperoxo species of the 3d series (Cr, Mn, Fe, Co, Ni, and Cu) with the ligand 14-TMC (1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane) via O⋯O bond cleavage. DFT calculations reveal that the barrier for O⋯O bond cleavage is higher with the late transition metals (Co, Ni, and Cu) than the early transition metals (Cr, Mn, and Fe), and the formed late metal-oxo species are also thermodynamically less stable. The higher barrier may be due to electronic repulsion because of the pairing of d electrons. In the late transition metal series, the electron goes into an antibonding orbital, which decreases the bond order and hence decreases the possibility of metal-oxo formation. Computed structural parameters and spin densities suggest that valence tautomerism occurs in the late transition metal-oxo species which remain as a metal-oxyl. Our findings support the concept of the "Oxo Wall".
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Affiliation(s)
- Monika
- Department of Chemistry, Central University of Haryana, Mahendergarh-123031, Haryana, India.
| | - Manjeet Kumar
- Department of Chemistry, Central University of Haryana, Mahendergarh-123031, Haryana, India.
| | - Somi
- Department of Chemistry, Central University of Haryana, Mahendergarh-123031, Haryana, India.
| | - Arup Sarkar
- Department of Chemistry, The University of Chicago 5735 South Ellis Avenue, Chicago, IL 60637, USA
| | - Manoj Kumar Gupta
- Department of Chemistry, Central University of Haryana, Mahendergarh-123031, Haryana, India.
| | - Azaj Ansari
- Department of Chemistry, Central University of Haryana, Mahendergarh-123031, Haryana, India.
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5
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Siddiqui YH, Shakaib M, Rasheed A, Ali HM, Azeem SMR, Siddique AH, Shafiq M. Enhancement of combustion effect leading to improved performance and exhaust emissions of an SI engine with ferrous oxide and graphite nanoparticles. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023:10.1007/s11356-023-28556-z. [PMID: 37552442 DOI: 10.1007/s11356-023-28556-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 06/28/2023] [Indexed: 08/09/2023]
Abstract
The present study was conducted to investigate the effectiveness of new, less toxic, less harmful, and nonmetallic graphite (G) and metallic iron oxide (Fe2O3) nanofuel additives by analyzing experimentally their consequences on exhaust emissions and performance of an air cooled, single cylinder, 4-stroke gasoline engine. Fe2O3 and graphite nanoparticles at 40, 80, and 120 mg/l of gasoline concentrations were mixed with gasoline by means of a magnetic stirrer. Brake power (BP), brake-specific fuel consumption (BSFC), torque (T), brake thermal efficiency (BTE), nitrogen oxides (NOx), carbon monoxide (CO), hydrocarbons (HC), and carbon dioxide (CO2) emissions were the investigated parameters. Experimental results indicated that G-blends showed a higher rise in brake power, brake thermal efficiency and torque and a greater reduction in the brake-specific fuel consumption as compared to that of Fe2O3 fuel blends. Moreover, the G-blends produced less NOx and CO2 than Fe2O3 blends but produced more emissions of CO and HC than that of Fe2O3 blends. On average, G-blends produced 0.46%, 0.71%, and 1.71% more torque, power, and BTE and 2.43%, 1.87%, and 13.39% less brake-specific fuel consumption (BSFC), NOx, and CO2 than Fe2O3 blends, respectively. So, in terms of the eight parameters, four performance parameters (i.e., T, BP, BSFC, BTE), and four engine emission exhaust indicators (i.e., CO, NOx, HC, CO2), graphite nanoparticles showed more positive results for 6 parameters (T, BP, BSFC, BTE, NOx, CO2), while two parameters HC and CO showed negative results with graphite as compared to that of Fe2O3 nanoparticles. So, overall, we conclude that nanoparticles of graphite are more engine and environment friendly than that of iron oxide fuel additives.
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Affiliation(s)
- Yasir Hussain Siddiqui
- Institute of Mechanical & Manufacturing Engineering, Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan, 64200, Pakistan
- Department of Mechanical Engineering, NED University of Engineering and Technology, Karachi, 75270, Pakistan
| | - Muhammad Shakaib
- Department of Mechanical Engineering, NED University of Engineering and Technology, Karachi, 75270, Pakistan
| | - Adnan Rasheed
- Institute of Mechanical & Manufacturing Engineering, Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan, 64200, Pakistan
| | - Hafiz Muhammad Ali
- Mechanical Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia.
- Interdisciplinary Research Center for Renewable Energy and Power Systems (IRC-REPS), King Fahd University of Petroleum and Minerals, Dhahran, 31261, Saudi Arabia.
| | - Syed Mohammad Rizwan Azeem
- Department of Mechanical Engineering, NED University of Engineering and Technology, Karachi, 75270, Pakistan
| | - Athar Husain Siddique
- Institute of Mechanical & Manufacturing Engineering, Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan, 64200, Pakistan
| | - Muhammad Shafiq
- Department of Mechanical Engineering, University of Engineering and Technology, Lahore, 54890, Pakistan
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Bio-Inspired Iron Pentadentate Complexes as Dioxygen Activators in the Oxidation of Cyclohexene and Limonene. Molecules 2023; 28:molecules28052240. [PMID: 36903486 PMCID: PMC10004738 DOI: 10.3390/molecules28052240] [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: 02/03/2023] [Revised: 02/24/2023] [Accepted: 02/25/2023] [Indexed: 03/04/2023] Open
Abstract
The use of dioxygen as an oxidant in fine chemicals production is an emerging problem in chemistry for environmental and economical reasons. In acetonitrile, the [(N4Py)FeII]2+ complex, [N4Py-N,N-bis(2-pyridylmethyl)-N-(bis-2-pyridylmethyl)amine] in the presence of the substrate activates dioxygen for the oxygenation of cyclohexene and limonene. Cyclohexane is oxidized mainly to 2-cyclohexen-1-one, and 2-cyclohexen-1-ol, cyclohexene oxide is formed in much smaller amounts. Limonene gives as the main products limonene oxide, carvone, and carveol. Perillaldehyde and perillyl alcohol are also present in the products but to a lesser extent. The investigated system is twice as efficient as the [(bpy)2FeII]2+/O2/cyclohexene system and comparable to the [(bpy)2MnII]2+/O2/limonene system. Using cyclic voltammetry, it has been shown that, when the catalyst, dioxgen, and substrate are present simultaneously in the reaction mixture, the iron(IV) oxo adduct [(N4Py)FeIV=O]2+ is formed, which is the oxidative species. This observation is supported by DFT calculations.
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7
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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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8
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Kaur L, Mandal D. Role of "S" Substitution on C-H Activation Reactivity of Iron(IV)-Oxo Cyclam Complexes: a Computational Investigation. Inorg Chem 2022; 61:14582-14590. [PMID: 36069431 DOI: 10.1021/acs.inorgchem.2c01504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A comprehensive density functional theory (DFT) investigation has been presented in this article to address the role of equatorial sulfur ligation in C-H activation. A non-heme iron-oxo compound with four nitrogen atoms constituting the equatorially connected macrocyclic framework (represented as N4) [Fe(IV)═O(THC)(CH3CN)]2+(THC = 1,4,8,11-tetrahydro1,4,8,11-tetraazacyclotetradecane) has been considered as the base compound. Other complexes have been anticipated by the sequential replacement of this nitrogen by sulfur, that is, N4, N3S1, N2S2, N1S3, and S4. Counterions, as always, have been considered to avoid the self-interaction error in DFT. Generally, the anti-conformers (with respect to equatorial N-H and Fe═O) turned out to be the most stable. It was found that with the enrichment of the equatorial sulfur atom, reactivity increases successively, that is, we get the trend N4 < N3S1 < N2S2 < N1S3 < S4. Our investigations have also verified the available experimental results where it has been reported that N2S2 is more reactive than N4 in their mixed conformation. In search of insights into this typical pattern of reactivity, the interplay of several factors has been recognized, such as the distortion energy which decreases for the transition states with the addition of sulfur; the spin density on the oxygen atom which increases implying that the radical character of abstractor increases on sulfur ligation; the energy of the electron acceptor orbital (the lowest unoccupied molecular orbital (σz2*)) which decreases continuously with the sulfur substitution; and the triplet-quintet oxidant energy gap which decreases consistently with S enrichment in the equatorial position. The computational predictions reported here, if further validated by experiments, will definitely encourage the synthesis of sulfur-ligated bio-inspired complexes instead of the ones constituting nitrogen exclusively.
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Affiliation(s)
- Lovleen Kaur
- School of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala 147004, Punjab, India
| | - Debasish Mandal
- School of Chemistry and Biochemistry, Thapar Institute of Engineering and Technology, Patiala 147004, Punjab, India
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9
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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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10
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‘Oxygen-Consuming Complexes’–Catalytic Effects of Iron–Salen Complexes with Dioxygen. Catalysts 2021. [DOI: 10.3390/catal11121462] [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
[(salen)FeIII]+MeCN complex is a useful catalyst for cyclohexene oxidation with dioxygen. As the main products, ketone and alcohol are formed. In acetonitrile, [(salen)FeII]MeCN is rapidly oxidized by dioxygen, forming iron(III) species. Voltammetric electroreduction of the [(salen)FeIII]+MeCN complex in the presence of dioxygen causes the increase in current observed, which indicates the existence of a catalytic effect. Further transformations of the oxygen-activated iron(III) salen complex generate an effective catalyst. Based on the catalytic and electrochemical results, as well as DFT calculations, possible forms of active species in c-C6H10 oxidation have been proposed.
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11
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Barman SK, Yang MY, Parsell TH, Green MT, Borovik AS. Semiempirical method for examining asynchronicity in metal-oxido-mediated C-H bond activation. Proc Natl Acad Sci U S A 2021; 118:e2108648118. [PMID: 34465626 PMCID: PMC8433561 DOI: 10.1073/pnas.2108648118] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The oxidation of substrates via the cleavage of thermodynamically strong C-H bonds is an essential part of mammalian metabolism. These reactions are predominantly carried out by enzymes that produce high-valent metal-oxido species, which are directly responsible for cleaving the C-H bonds. While much is known about the identity of these transient intermediates, the mechanistic factors that enable metal-oxido species to accomplish such difficult reactions are still incomplete. For synthetic metal-oxido species, C-H bond cleavage is often mechanistically described as synchronous, proton-coupled electron transfer (PCET). However, data have emerged that suggest that the basicity of the M-oxido unit is the key determinant in achieving enzymatic function, thus requiring alternative mechanisms whereby proton transfer (PT) has a more dominant role than electron transfer (ET). To bridge this knowledge gap, the reactivity of a monomeric MnIV-oxido complex with a series of external substrates was studied, resulting in a spread of over 104 in their second-order rate constants that tracked with the acidity of the C-H bonds. Mechanisms that included either synchronous PCET or rate-limiting PT, followed by ET, did not explain our results, which led to a proposed PCET mechanism with asynchronous transition states that are dominated by PT. To support this premise, we report a semiempirical free energy analysis that can predict the relative contributions of PT and ET for a given set of substrates. These findings underscore why the basicity of M-oxido units needs to be considered in C-H functionalization.
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Affiliation(s)
- Suman K Barman
- Department of Chemistry, University of California Irvine, CA 92697;
| | - Meng-Yin Yang
- Department of Chemistry, University of California Irvine, CA 92697
| | | | - Michael T Green
- Department of Chemistry, University of California Irvine, CA 92697;
- Department of Molecular Biosciences and Biochemistry, University of California Irvine, CA 92697
| | - A S Borovik
- Department of Chemistry, University of California Irvine, CA 92697;
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12
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Brewer SM, Schwartz TM, Mekhail MA, Turan LS, Prior TJ, Hubin TJ, Janesko BG, Green KN. Mechanistic Insights into Iron-Catalyzed C–H Bond Activation and C–C Coupling. Organometallics 2021; 40:2467-2477. [DOI: 10.1021/acs.organomet.1c00211] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Samantha M. Brewer
- Department of Chemistry and Biochemistry, Texas Christian University, 2950 S. Bowie, Fort Worth, Texas 76129, United States
| | - Timothy M. Schwartz
- Department of Chemistry and Biochemistry, Texas Christian University, 2950 S. Bowie, Fort Worth, Texas 76129, United States
| | - Magy A. Mekhail
- Department of Chemistry and Biochemistry, Texas Christian University, 2950 S. Bowie, Fort Worth, Texas 76129, United States
| | - Lara S. Turan
- Department of Chemistry and Biochemistry, Texas Christian University, 2950 S. Bowie, Fort Worth, Texas 76129, United States
| | - Timothy J. Prior
- Department of Chemistry and Biochemistry, University of Hull, Hull HU6 7RX, U.K
| | - Timothy J. Hubin
- Department of Chemistry and Physics, Southwestern Oklahoma State University, 100 Campus Drive, Weatherford, Oklahoma 73096, United States
| | - Benjamin G. Janesko
- Department of Chemistry and Biochemistry, Texas Christian University, 2950 S. Bowie, Fort Worth, Texas 76129, United States
| | - Kayla N. Green
- Department of Chemistry and Biochemistry, Texas Christian University, 2950 S. Bowie, Fort Worth, Texas 76129, United States
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13
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Xia Y, Li N, Lu W, Wang W, Yao Y, Zhu Z, Xu T, Gu Y, Chen W. High-valent iron-oxo species on pyridine-containing MWCNTs generated in a solar-induced H 2O 2 activation system for the removal of antimicrobials. CHEMOSPHERE 2021; 273:129545. [PMID: 33497981 DOI: 10.1016/j.chemosphere.2021.129545] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 12/18/2020] [Accepted: 01/02/2021] [Indexed: 06/12/2023]
Abstract
The overuse of antimicrobials has resulted in serious damage to the ecosystem and human health. Therefore, the development of an efficient, stable, and reusable catalyst to eliminate antimicrobials under mild conditions is highly desired. Drawing inspiration from the metabolism of drugs by the enzymes in the human body, such as heme catalase, we developed a simulated enzyme catalyst, perchloride iron phthalocyanine (FePcCl16), immobilized on pyridine-modified multiwalled carbon nanotubes (FePcCl16-Py-MWCNTs). In the catalyst, FePcCl16 worked as the active site, and the axial fifth ligand, 4-aminopyridine, was introduced to cleave H2O2 heterolytically. Inspired by the reaction mechanism of heme catalase and H2O2, the catalytic system was designed based on FePcCl16-Py-MWCNTs for oxidizing 4-chloro-3,5-dimethylphenol (PCMX) by H2O2 activation. The results showed that the catalytic activity of the system was significantly increased under simulated solar light irradiation, which can promote electron transfer for heterolytic cleavage of H2O2. The enzyme-like catalyst achieved much higher catalytic activity than the Fenton reaction when the pH was close to neutral. It turned out that the main active species was high-valent iron-oxo (Fe(Ⅳ) = O) rather than hydroxyl radial (•OH) or superoxide radical (•O2-), different from most mechanisms. Ultraperformance liquid chromatography-high-definition mass spectrometry showed that the substrate was degraded to small molecule acids by Fe(Ⅳ) = O active species and further mineralization indicated by total organic carbon. The catalytic system exhibited highly efficient, stable, recyclable catalytic performance under mild conditions and did not cause secondary pollution to the environment. This study of a simulated enzyme catalytic system offers important insight into sewage treatment.
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Affiliation(s)
- Yun Xia
- National Engineering Lab for Textile Fiber Materials & Processing Technology (Zhejiang), Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Nan Li
- National Engineering Lab for Textile Fiber Materials & Processing Technology (Zhejiang), Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Wangyang Lu
- National Engineering Lab for Textile Fiber Materials & Processing Technology (Zhejiang), Zhejiang Sci-Tech University, Hangzhou, 310018, China.
| | - Wentao Wang
- National Engineering Lab for Textile Fiber Materials & Processing Technology (Zhejiang), Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Yuyuan Yao
- National Engineering Lab for Textile Fiber Materials & Processing Technology (Zhejiang), Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Zhexin Zhu
- National Engineering Lab for Textile Fiber Materials & Processing Technology (Zhejiang), Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Tiefeng Xu
- National Engineering Lab for Textile Fiber Materials & Processing Technology (Zhejiang), Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Yan Gu
- National Engineering Lab for Textile Fiber Materials & Processing Technology (Zhejiang), Zhejiang Sci-Tech University, Hangzhou, 310018, China
| | - Wenxing Chen
- National Engineering Lab for Textile Fiber Materials & Processing Technology (Zhejiang), Zhejiang Sci-Tech University, Hangzhou, 310018, China.
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14
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Yamada Y, Kura J, Toyoda Y, Tanaka K. High catalytic methane oxidation activity of monocationic μ-nitrido-bridged iron phthalocyanine dimer with sixteen methyl groups. Dalton Trans 2021; 50:6718-6724. [PMID: 33908999 DOI: 10.1039/d1dt00941a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Herein, we report the highly potent catalytic methane oxidation activity of a monocationic μ-nitrido-bridged iron phthalocyanine dimer with 16 peripheral methyl groups. It was confirmed that this complex oxidized methane stably into MeOH, HCHO, and HCOOH in a catalytic manner in an acidic aqueous solution containing excess H2O2 at 60 °C. The total turnover number of the reaction reached 135 after 12 h, which is almost seven times higher than that of a monocatinoic μ-nitrido-bridged iron phthalocyanine dimer with no peripheral substituents. This suggests that the increased number of peripheral electron-donating substituents could have facilitated the generation of a reactive high-valent iron-oxo species as well as hydrogen abstraction from methane by the reactive iron-oxo species.
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Affiliation(s)
- Yasuyuki Yamada
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan. and Research Center for Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan and JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Jyunichi Kura
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.
| | - Yuka Toyoda
- Research Center for Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Kentaro Tanaka
- Department of Chemistry, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan.
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15
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Wegeberg C, Skavenborg ML, Liberato A, McPherson JN, Browne WR, Hedegård ED, McKenzie CJ. Engineering the Oxidative Potency of Non-Heme Iron(IV) Oxo Complexes in Water for C-H Oxidation by a cis Donor and Variation of the Second Coordination Sphere. Inorg Chem 2021; 60:1975-1984. [PMID: 33470794 DOI: 10.1021/acs.inorgchem.0c03441] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A series of iron(IV) oxo complexes, which differ in the donor (CH2py or CH2COO-) cis to the oxo group, three with hemilabile pendant donor/second coordination sphere base/acid arms (pyH/py or ROH), have been prepared in water at pH 2 and 7. The νFe═O values of 832 ± 2 cm-1 indicate similar FeIV═O bond strengths; however, different reactivities toward C-H substrates in water are observed. HAT occurs at rates that differ by 1 order of magnitude with nonclassical KIEs (kH/kD = 30-66) consistent with hydrogen atom tunneling. Higher KIEs correlate with faster reaction rates as well as a greater thermodynamic stability of the iron(III) resting states. A doubling in rate from pH 7 to pH 2 for substrate C-H oxidation by the most potent complex, that with a cis-carboxylate donor, [FeIVO(Htpena)]2+, is observed. Supramolecular assistance by the first and second coordination spheres in activating the substrate is proposed. The lifetime of this complex in the absence of a C-H substrate is the shortest (at pH 2, 3 h vs up to 1.3 days for the most stable complex), implying that slow water oxidation is a competing background reaction. The iron(IV)═O complex bearing an alcohol moiety in the second coordination sphere displays significantly shorter lifetimes due to a competing selective intramolecular oxidation of the ligand.
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Affiliation(s)
- Christina Wegeberg
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.,Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Mathias L Skavenborg
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.,Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, New South Wales, Australia
| | - Andrea Liberato
- Universidad de Cádiz, Facultad de Ciencias, Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Puerto Real, Cádiz 11510, Spain
| | - James N McPherson
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | - Wesley R Browne
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Erik D Hedegård
- Division of Theoretical Chemistry, Lund University, Naturvetarvägen 14, 221 00 Lund, Sweden
| | - Christine J McKenzie
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
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16
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Nasibipour M, Safaei E, Wojtczak A, Jagličić Z, Galindo A, Masoumpour MS. A biradical oxo-molybdenum complex containing semiquinone and o-aminophenol benzoxazole-based ligands. RSC Adv 2020; 10:40853-40866. [PMID: 35519205 PMCID: PMC9059147 DOI: 10.1039/d0ra06351g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 10/16/2020] [Indexed: 12/27/2022] Open
Abstract
We report a new mononuclear molybdenum(iv) complex, MoOLBISLSQ, in which LSQ (2,4-di-tert-butyl o-semibenzoquinone ligand) has been prepared from the reaction of the o-iminosemibenzoquinone form of a tridentate non-innocent benzoxazole ligand, LBIS, and MoO2(acac)2. The complex was characterized by X-ray crystallography, elemental analysis, IR and UV-vis spectroscopy and magnetic susceptibility measurements. The crystal structure of MoOLBISLSQ revealed a distorted octahedral geometry around the metal centre, surrounded by one O and two N atoms of LBIS and two O atoms of LSQ. The effective magnetic moment (μ eff) of MoOLBISLSQ decreased from 2.36 to 0.2 μB in the temperature range of 290 to 2 K, indicating a singlet ground state caused by antiferromagnetic coupling between the metal and ligand centred unpaired electrons. Also, the latter led to the EPR silence of the complex. Cyclic voltammetry (CV) studies indicate both ligand and metal-centered redox processes. MoOLBISLSQ was applied as a catalyst for the oxidative cleavage of cyclohexene to adipic acid and selective oxidation of sulfides to sulfones with aqueous hydrogen peroxide.
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Affiliation(s)
- Mina Nasibipour
- Department of Chemistry, College of Sciences, Shiraz University 71454 Shiraz Iran
| | - Elham Safaei
- Department of Chemistry, College of Sciences, Shiraz University 71454 Shiraz Iran
| | - Andrzej Wojtczak
- Nicolaus Copernicus University, Faculty of Chemistry 87-100 Torun Poland
| | - Zvonko Jagličić
- Institute of Mathematics, Physics and Mechanics & Faculty of Civil and Geodetic Engineering, University of Ljubljana Jadranska 19 Ljubljana Slovenia
| | - Agustín Galindo
- Departamento de Química Inorgánica, Facultad de Química, Universidad de Sevilla Aptdo. 1203 41071 Sevilla Spain
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17
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Kannan N, Patil AR, Sinha A. Direct C-H bond halogenation and pseudohalogenation of hydrocarbons mediated by high-valent 3d metal-oxo species. Dalton Trans 2020; 49:14344-14360. [PMID: 33057538 DOI: 10.1039/d0dt02533j] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Late-stage direct functionalization of the C-H bond is synthetically desirable. Metalloenzymes having metal-oxo active sites are well known to selectively catalyze hydroxylation and halogenation reactions with high efficiency. This review highlights the recent developments in the field of direct C-H halogenation and pseudohalogenation reactions catalyzed by the functional models of metalloenzymes.
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Affiliation(s)
- Neppoliyan Kannan
- Department of Chemistry, School of Advanced Science, Vellore Institute of Technology, Vellore-632014, Tamil Nadu, India.
| | - Akshay R Patil
- Department of Chemistry, School of Advanced Science, Vellore Institute of Technology, Vellore-632014, Tamil Nadu, India.
| | - Arup Sinha
- Department of Chemistry, School of Advanced Science, Vellore Institute of Technology, Vellore-632014, Tamil Nadu, India.
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18
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Shteinman AA. Bioinspired Oxidation of Methane: From Academic Models of Methane Monooxygenases to Direct Conversion of Methane to Methanol. KINETICS AND CATALYSIS 2020. [DOI: 10.1134/s0023158420030180] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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19
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Rios N, Radi R, Kalyanaraman B, Zielonka J. Tracking isotopically labeled oxidants using boronate-based redox probes. J Biol Chem 2020; 295:6665-6676. [PMID: 32217693 DOI: 10.1074/jbc.ra120.013402] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 03/26/2020] [Indexed: 01/01/2023] Open
Abstract
Reactive oxygen and nitrogen species have been implicated in many biological processes and diseases, including immune responses, cardiovascular dysfunction, neurodegeneration, and cancer. These chemical species are short-lived in biological settings, and detecting them in these conditions and diseases requires the use of molecular probes that form stable, easily detectable, products. The chemical mechanisms and limitations of many of the currently used probes are not well-understood, hampering their effective applications. Boronates have emerged as a class of probes for the detection of nucleophilic two-electron oxidants. Here, we report the results of an oxygen-18-labeling MS study to identify the origin of oxygen atoms in the oxidation products of phenylboronate targeted to mitochondria. We demonstrate that boronate oxidation by hydrogen peroxide, peroxymonocarbonate, hypochlorite, or peroxynitrite involves the incorporation of oxygen atoms from these oxidants. We therefore conclude that boronates can be used as probes to track isotopically labeled oxidants. This suggests that the detection of specific products formed from these redox probes could enable precise identification of oxidants formed in biological systems. We discuss the implications of these results for understanding the mechanism of conversion of the boronate-based redox probes to oxidant-specific products.
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Affiliation(s)
- Natalia Rios
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, 11800 Montevideo, Uruguay.,Centro de Investigaciones Biomédicas (CEINBIO), Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Rafael Radi
- Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, 11800 Montevideo, Uruguay.,Centro de Investigaciones Biomédicas (CEINBIO), Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | | | - Jacek Zielonka
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
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20
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Park H, Lee D. Ligand Taxonomy for Bioinorganic Modeling of Dioxygen-Activating Non-Heme Iron Enzymes. Chemistry 2020; 26:5916-5926. [PMID: 31909506 DOI: 10.1002/chem.201904975] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/04/2020] [Indexed: 12/15/2022]
Abstract
Novel functions emerge from novel structures. To develop efficient catalytic systems for challenging chemical transformations, chemists often seek inspirations from enzymatic catalysis. A large number of iron complexes supported by nitrogen-rich multidentate ligands have thus been developed to mimic oxo-transfer reactivity of dioxygen-activating metalloenzymes. Such efforts have significantly advanced our understanding of the reaction mechanisms by trapping key intermediates and elucidating their geometric and electronic properties. Critical to the success of this biomimetic approach is the design and synthesis of elaborate ligand systems to balance the thermodynamic stability, structural adaptability, and chemical reactivity. In this Concept article, representative design strategies for biomimetic atom-transfer chemistry are discussed from the perspectives of "ligand builders". Emphasis is placed on how the primary coordination sphere is constructed, and how it can be elaborated further by rational design for desired functions.
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Affiliation(s)
- Hyunchang Park
- Department of Chemistry, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Korea
| | - Dongwhan Lee
- Department of Chemistry, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Korea
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21
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Krzystek J, Schnegg A, Aliabadi A, Holldack K, Stoian SA, Ozarowski A, Hicks SD, Abu-Omar MM, Thomas KE, Ghosh A, Caulfield KP, Tonzetich ZJ, Telser J. Advanced Paramagnetic Resonance Studies on Manganese and Iron Corroles with a Formal d 4 Electron Count. Inorg Chem 2020; 59:1075-1090. [PMID: 31909979 DOI: 10.1021/acs.inorgchem.9b02635] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Metallocorroles wherein the metal ion is MnIII and formally FeIV are studied here using field- and frequency-domain electron paramagnetic resonance techniques. The MnIII corrole, Mn(tpfc) (tpfc = 5,10,15-tris(pentafluorophenyl)corrole trianion), exhibits the following S = 2 zero-field splitting (zfs) parameters: D = -2.67(1) cm-1, |E| = 0.023(5) cm-1. This result and those for other MnIII tetrapyrroles indicate that when D ≈ - 2.5 ± 0.5 cm-1 for 4- or 5-coordinate and D ≈ - 3.5 ± 0.5 cm-1 for 6-coordinate complexes, the ground state description is [MnIII(Cor3-)]0 or [MnIII(P2-)]+ (Cor = corrole, P = porphyrin). The situation for formally FeIV corroles is more complicated, and it has been shown that for Fe(Cor)X, when X = Ph (phenyl), the ground state is a spin triplet best described by [FeIV(Cor3-)]+, but when X = halide, the ground state corresponds to [FeIII(Cor•2-)]+, wherein an intermediate spin (S = 3/2) FeIII is antiferromagnetically coupled to a corrole radical dianion (S = 1/2) to also give an S = 1 ground state. These two valence isomers can be distinguished by their zfs parameters, as determined here for Fe(tpc)X, X = Ph, Cl (tpc = 5,10,15-triphenylcorrole trianion). The complex with axial phenyl gives D = 21.1(2) cm-1, while that with axial chloride gives D = 14.6(1) cm-1. The D value for Fe(tpc)Ph is in rough agreement with the range of values reported for other FeIV complexes. In contrast, the D value for Fe(tpc)Cl is inconsistent with an FeIV description and represents a different type of iron center. Computational studies corroborate the zfs for the two types of iron corrole complexes. Thus, the zfs of metallocorroles can be diagnostic as to the electronic structure of a formally high oxidation state metallocorrole, and by extension to metalloporphyrins, although such studies have yet to be performed.
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Affiliation(s)
- J Krzystek
- National High Magnetic Field Laboratory , Florida State University , Tallahassee , Florida 32310 , United States
| | - Alexander Schnegg
- EPR Research Group , Max Planck Institute for Chemical Energy Conversion , Stiftstraße 34-36 , D-45470 Mülheim Ruhr , Germany.,Berlin Joint EPR Laboratory , Helmholtz-Zentrum Berlin , Kekulestraße 5 , D-12489 Berlin , Germany
| | - Azar Aliabadi
- Berlin Joint EPR Laboratory , Helmholtz-Zentrum Berlin , Kekulestraße 5 , D-12489 Berlin , Germany
| | - Karsten Holldack
- Institut für Methoden und Instrumentierung der Forschung mit Synchrotronstrahlung am Elektronenspeicherring BESSY II , Albert-Einstein-Straße 15 , D-12489 Berlin , Germany
| | - Sebastian A Stoian
- Department of Chemistry , University of Idaho , Moscow , Idaho 83844 , United States
| | - Andrew Ozarowski
- National High Magnetic Field Laboratory , Florida State University , Tallahassee , Florida 32310 , United States
| | - Scott D Hicks
- Department of Chemistry , Purdue University , West Lafayette , Indiana 47907 , United States
| | - Mahdi M Abu-Omar
- Departments of Chemistry and Biochemistry , University of California , Santa Barbara , California 93106-9510 , United States
| | - Kolle E Thomas
- Department of Chemistry , UiT-The Arctic University of Norway , N-9037 Tromsø , Norway
| | - Abhik Ghosh
- Department of Chemistry , UiT-The Arctic University of Norway , N-9037 Tromsø , Norway
| | - Kenneth P Caulfield
- Department of Chemistry , University of Texas at San Antonio (UTSA) , One UTSA Circle , San Antonio , Texas 78249 , United States
| | - Zachary J Tonzetich
- Department of Chemistry , University of Texas at San Antonio (UTSA) , One UTSA Circle , San Antonio , Texas 78249 , United States
| | - Joshua Telser
- Department of Biological, Physical, and Health Sciences , Roosevelt University , Chicago , Illinois 60605 , United States
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22
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Wang Y, Li Z, Li C, Qi Y, Li Q, Zhang P. [FeIV(O )(TMC)(Lax)]n+ for O-transfer reaction: Insight into the steric hindrance effect of the equatorial ligand. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2019.136858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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23
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Liu Y, You T, Wang HX, Tang Z, Zhou CY, Che CM. Iron- and cobalt-catalyzed C(sp3)–H bond functionalization reactions and their application in organic synthesis. Chem Soc Rev 2020; 49:5310-5358. [DOI: 10.1039/d0cs00340a] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This review highlights the developments in iron and cobalt catalyzed C(sp3)–H bond functionalization reactions with emphasis on their applications in organic synthesis, i.e. natural products and pharmaceuticals synthesis and/or modification.
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Affiliation(s)
- Yungen Liu
- Department of Chemistry
- Southern University of Science and Technology
- Shenzhen
- P. R. China
| | - Tingjie You
- Department of Chemistry
- State Key Laboratory of Synthetic Chemistry
- The University of Hong Kong
- Hong Kong
- P. R. China
| | - Hai-Xu Wang
- Department of Chemistry
- State Key Laboratory of Synthetic Chemistry
- The University of Hong Kong
- Hong Kong
- P. R. China
| | - Zhou Tang
- Department of Chemistry
- State Key Laboratory of Synthetic Chemistry
- The University of Hong Kong
- Hong Kong
- P. R. China
| | - Cong-Ying Zhou
- Department of Chemistry
- State Key Laboratory of Synthetic Chemistry
- The University of Hong Kong
- Hong Kong
- P. R. China
| | - Chi-Ming Che
- Department of Chemistry
- Southern University of Science and Technology
- Shenzhen
- P. R. China
- Department of Chemistry
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24
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Sabenya G, Gamba I, Gómez L, Clémancey M, Frisch JR, Klinker EJ, Blondin G, Torelli S, Que L, Martin-Diaconescu V, Latour JM, Lloret-Fillol J, Costas M. Octahedral iron(iv)-tosylimido complexes exhibiting single electron-oxidation reactivity. Chem Sci 2019; 10:9513-9529. [PMID: 32055323 PMCID: PMC6979323 DOI: 10.1039/c9sc02526j] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 08/17/2019] [Indexed: 11/28/2022] Open
Abstract
High valent iron species are very reactive molecules involved in oxidation reactions of relevance to biology and chemical synthesis. Herein we describe iron(iv)-tosylimido complexes [FeIV(NTs)(MePy2tacn)](OTf)2 (1(IV)[double bond, length as m-dash]NTs) and [FeIV(NTs)(Me2(CHPy2)tacn)](OTf)2 (2(IV)[double bond, length as m-dash]NTs), (MePy2tacn = N-methyl-N,N-bis(2-picolyl)-1,4,7-triazacyclononane, and Me2(CHPy2)tacn = 1-(di(2-pyridyl)methyl)-4,7-dimethyl-1,4,7-triazacyclononane, Ts = Tosyl). 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs are rare examples of octahedral iron(iv)-imido complexes and are isoelectronic analogues of the recently described iron(iv)-oxo complexes [FeIV(O)(L)]2+ (L = MePy2tacn and Me2(CHPy2)tacn, respectively). 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs are metastable and have been spectroscopically characterized by HR-MS, UV-vis, 1H-NMR, resonance Raman, Mössbauer, and X-ray absorption (XAS) spectroscopy as well as by DFT computational methods. Ferric complexes [FeIII(HNTs)(L)]2+, 1(III)-NHTs (L = MePy2tacn) and 2(III)-NHTs (L = Me2(CHPy2)tacn) have been isolated after the decay of 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs in solution, spectroscopically characterized, and the molecular structure of [FeIII(HNTs)(MePy2tacn)](SbF6)2 determined by single crystal X-ray diffraction. Reaction of 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs with different p-substituted thioanisoles results in the transfer of the tosylimido moiety to the sulphur atom producing sulfilimine products. In these reactions, 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs behave as single electron oxidants and Hammett analyses of reaction rates evidence that tosylimido transfer is more sensitive than oxo transfer to charge effects. In addition, reaction of 1(IV)[double bond, length as m-dash]NTs and 2(IV)[double bond, length as m-dash]NTs with hydrocarbons containing weak C-H bonds results in the formation of 1(III)-NHTs and 2(III)-NHTs respectively, along with the oxidized substrate. Kinetic analyses indicate that reactions proceed via a mechanistically unusual HAT reaction, where an association complex precedes hydrogen abstraction.
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Affiliation(s)
- Gerard Sabenya
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
| | - Ilaria Gamba
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
| | - Laura Gómez
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
| | - Martin Clémancey
- Univ. Grenoble-Alpes , CNRS , CEA , IRIG , DIESE , CBM , Grenoble 38000 , France
| | - Jonathan R Frisch
- Department of Chemistry , University of Minnesota , Pleasant Str 207 , Minneapolis , Minnesota , USA
| | - Eric J Klinker
- Department of Chemistry , University of Minnesota , Pleasant Str 207 , Minneapolis , Minnesota , USA
| | - Geneviève Blondin
- Univ. Grenoble-Alpes , CNRS , CEA , IRIG , DIESE , CBM , Grenoble 38000 , France
| | - Stéphane Torelli
- Univ. Grenoble-Alpes , CNRS , CEA , IRIG , DIESE , CBM , Grenoble 38000 , France
| | - Lawrence Que
- Department of Chemistry , University of Minnesota , Pleasant Str 207 , Minneapolis , Minnesota , USA
| | - Vlad Martin-Diaconescu
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
- Institute of Chemical Research of Catalonia (ICIQ) , The Barcelona Institute of Science and Technology , Avinguda Països Catalans 16 , 43007 Tarragona , Spain .
| | - Jean-Marc Latour
- Univ. Grenoble-Alpes , CNRS , CEA , IRIG , DIESE , CBM , Grenoble 38000 , France
| | - Julio Lloret-Fillol
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
- Institute of Chemical Research of Catalonia (ICIQ) , The Barcelona Institute of Science and Technology , Avinguda Països Catalans 16 , 43007 Tarragona , Spain .
- Catalan Institution for Research and Advanced Studies (ICREA) , Passeig Lluïs Companys, 23 , 08010 , Barcelona , Spain
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC) , Departament de Química , Universitat de Girona , Campus Montilivi , E17071 Girona , Spain .
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25
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Das A, Nutting JE, Stahl SS. Electrochemical C-H oxygenation and alcohol dehydrogenation involving Fe-oxo species using water as the oxygen source. Chem Sci 2019; 10:7542-7548. [PMID: 31588305 PMCID: PMC6761876 DOI: 10.1039/c9sc02609f] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 06/25/2019] [Indexed: 11/30/2022] Open
Abstract
High-valent iron-oxo complexes are key intermediates in C-H functionalization reactions. Herein, we report the generation of a (TAML)Fe-oxo species (TAML = tetraamido macrocyclic ligand) via electrochemical proton-coupled oxidation of the corresponding (TAML)FeIII-OH2 complex. Cyclic voltammetry (CV) and spectroelectrochemical studies are used to elucidate the relevant (TAML)Fe redox processes and determine the predominant (TAML)Fe species present in solution during bulk electrolysis. Evidence for iron(iv) and iron(v) species is presented, and these species are used in the electrochemical oxygenation of benzylic C-H bonds and dehydrogenation of alcohols to ketones.
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Affiliation(s)
- Amit Das
- Department of Chemistry , University of Wisconsin-Madison , 1101 University Avenue , Madison , Wisconsin 53706 , USA .
| | - Jordan E Nutting
- Department of Chemistry , University of Wisconsin-Madison , 1101 University Avenue , Madison , Wisconsin 53706 , USA .
| | - Shannon S Stahl
- Department of Chemistry , University of Wisconsin-Madison , 1101 University Avenue , Madison , Wisconsin 53706 , USA .
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26
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Barman SK, Jones JR, Sun C, Hill EA, Ziller JW, Borovik AS. Regulating the Basicity of Metal-Oxido Complexes with a Single Hydrogen Bond and Its Effect on C-H Bond Cleavage. J Am Chem Soc 2019; 141:11142-11150. [PMID: 31274298 DOI: 10.1021/jacs.9b03688] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The functionalization of C-H bonds is an essential reaction in biology and chemistry. Metalloenzymes that often exhibit this type of reactivity contain metal-oxido intermediates that are directly involved in the initial cleavage of the C-H bonds. Regulation of the cleavage process is achieved, in part, by hydrogen bonds that are proximal to the metal-oxido units, yet our understanding of their exact role(s) is still emerging. To gain further information into the role of H-bonds on C-H bond activation, a hybrid set of urea-containing tripodal ligands has been developed in which a single H-bond can be adjusted through changes in the properties of one ureayl N-H bond. This modularity is achieved by appending a phenyl ring with different para-substituents from one ureayl NH group. The ligands have been used to prepare a series of MnIII-oxido complexes, and a Hammett correlation was found between the pKa values of the complexes and the substituents on the phenyl ring that was explained within the context of changes to the H-bonds involving the MnIII-oxido unit. The complexes were tested for their reactivity toward 9,10-dihydroanthracene (DHA), and a Hammett correlation was found between the second-order rate constants for the reactions and the pKa values. Studies to determine activation parameters and the kinetic isotope effects are consistent with a mechanism in which rate-limiting proton transfer is an important contributor. However, additional reactivity studies with xanthene found a significant increase in the rate constant compared to DHA, even though the substrates have the same pKa(C-H) values. These results do not support a discrete proton-transfer/electron-transfer process, but rather an asynchronous mechanism in which the proton and electron are transferred unequally at the transition state.
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Affiliation(s)
- Suman K Barman
- Department of Chemistry , University of California-Irvine , 1102 Natural Sciences II , Irvine , California 92697 , United States
| | - Jason R Jones
- Department of Chemistry , University of California-Irvine , 1102 Natural Sciences II , Irvine , California 92697 , United States
| | - Chen Sun
- Department of Chemistry , University of California-Irvine , 1102 Natural Sciences II , Irvine , California 92697 , United States
| | - Ethan A Hill
- 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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27
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Mukherjee M, Dey A. Electron Transfer Control of Reductase versus Monooxygenase: Catalytic C-H Bond Hydroxylation and Alkene Epoxidation by Molecular Oxygen. ACS CENTRAL SCIENCE 2019; 5:671-682. [PMID: 31041387 PMCID: PMC6487540 DOI: 10.1021/acscentsci.9b00046] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Indexed: 05/11/2023]
Abstract
Catalytic oxidation of organic substrates, using a green oxidant like O2, has been a long-term goal of the scientific community. In nature, these oxidations are performed by metalloenzymes that generate highly oxidizing species from O2, which, in turn, can oxidize very stable organic substrates, e.g., mono-/dioxygenases. The same oxidants are produced during O2 reduction/respiration in the mitochondria but are reduced by electron transfer, i.e., reductases. Iron porphyrin mimics of the active site of cytochrome P450 (Cyt P450) are created atop a self-assembled monolayer covered electrode. The rate of electron transfer from the electrode to the iron porphyrin site is attenuated to derive monooxygenase reactivity from these constructs that otherwise show O2 reductase activity. Catalytic hydroxylation of strong C-H bonds to alcohol and epoxidation of alkenes, using molecular O2 (with 18O2 incorporation), is demonstrated with turnover numbers >104. Uniquely, one of the two iron porphyrin catalysts used shows preferential oxidation of 2° C-H bonds of cycloalkanes to alcohols over 3° C-H bonds without overoxidation to ketones. Mechanistic investigations with labeled substrates indicate that a compound I (FeIV=O bound to a porphyrin cation radical) analogue, formed during O2 reduction, is the primary oxidant. The selectivity is determined by the shape of the distal pocket of the catalyst, which, in turn, is determined by the substituents on the periphery of the porphyrin macrocycle.
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Affiliation(s)
| | - Abhishek Dey
- Address:
Department of Inorganic
Chemistry, Indian Association for the Cultivation of Science, 2A&2B
Raja SC Mullick Road, Jadavpur, Kolkata, West Bengal, India 700032.
E-mail:
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28
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Stoyanovsky DA, Tyurina YY, Shrivastava I, Bahar I, Tyurin VA, Protchenko O, Jadhav S, Bolevich SB, Kozlov AV, Vladimirov YA, Shvedova AA, Philpott CC, Bayir H, Kagan VE. Iron catalysis of lipid peroxidation in ferroptosis: Regulated enzymatic or random free radical reaction? Free Radic Biol Med 2019; 133:153-161. [PMID: 30217775 PMCID: PMC6555767 DOI: 10.1016/j.freeradbiomed.2018.09.008] [Citation(s) in RCA: 205] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 09/06/2018] [Accepted: 09/09/2018] [Indexed: 12/14/2022]
Abstract
Duality of iron as an essential cofactor of many enzymatic metabolic processes and as a catalyst of poorly controlled redox-cycling reactions defines its possible biological beneficial and hazardous role in the body. In this review, we discuss these two "faces" of iron in a newly conceptualized program of regulated cell death, ferroptosis. Ferroptosis is a genetically programmed iron-dependent form of regulated cell death driven by enhanced lipid peroxidation and insufficient capacity of thiol-dependent mechanisms (glutathione peroxidase 4, GPX4) to eliminate hydroperoxy-lipids. We present arguments favoring the enzymatic mechanisms of ferroptotically engaged non-heme iron of 15-lipoxygenases (15-LOX) in complexes with phosphatidylethanolamine binding protein 1 (PEBP1) as a catalyst of highly selective and specific oxidation reactions of arachidonoyl- (AA) and adrenoyl-phosphatidylethanolamines (PE). We discuss possible role of iron chaperons as control mechanisms for guided iron delivery directly to their "protein clients" thus limiting non-enzymatic redox-cycling reactions. We also consider opportunities of loosely-bound iron to contribute to the production of pro-ferroptotic lipid oxidation products. Finally, we propose a two-stage iron-dependent mechanism for iron in ferroptosis by combining its catalytic role in the 15-LOX-driven production of 15-hydroperoxy-AA-PE (HOO-AA-PE) as well as possible involvement of loosely-bound iron in oxidative cleavage of HOO-AA-PE to oxidatively truncated electrophiles capable of attacking nucleophilic targets in yet to be identified proteins leading to cell demise.
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Affiliation(s)
- D A Stoyanovsky
- Center for Free Radical and Antioxidant Heath, Department of Environmental Health, University of Pittsburgh, USA
| | - Y Y Tyurina
- Center for Free Radical and Antioxidant Heath, Department of Environmental Health, University of Pittsburgh, USA
| | - I Shrivastava
- Center for Free Radical and Antioxidant Heath, Department of Environmental Health, University of Pittsburgh, USA; Department of Computational and Systems Biology, University of Pittsburgh, USA
| | - I Bahar
- Department of Computational and Systems Biology, University of Pittsburgh, USA
| | - V A Tyurin
- Center for Free Radical and Antioxidant Heath, Department of Environmental Health, University of Pittsburgh, USA
| | - O Protchenko
- Genetics and Metabolism Section, Liver Diseases Branch, NIDDK, NIH, Bethesda, USA
| | - S Jadhav
- Genetics and Metabolism Section, Liver Diseases Branch, NIDDK, NIH, Bethesda, USA
| | - S B Bolevich
- Laboratory of Navigational Redox Lipidomics and Department of Human Pathology, IM Sechenov Moscow State Medical University, Russian Federation
| | - A V Kozlov
- L Boltzmann Institute for Experimental and Clinical Traumatology in AUVA Research Center, Vienna, Austria; Laboratory of Navigational Redox Lipidomics and Department of Human Pathology, IM Sechenov Moscow State Medical University, Russian Federation
| | - Y A Vladimirov
- Laboratory of Navigational Redox Lipidomics and Department of Human Pathology, IM Sechenov Moscow State Medical University, Russian Federation
| | - A A Shvedova
- Exposure Assessment Branch, NIOSH/CDC, Morgantown, WV, USA
| | - C C Philpott
- Genetics and Metabolism Section, Liver Diseases Branch, NIDDK, NIH, Bethesda, USA
| | - H Bayir
- Center for Free Radical and Antioxidant Heath, Department of Environmental Health, University of Pittsburgh, USA; Departments of Critical Care Medicine, University of Pittsburgh, USA
| | - V E Kagan
- Center for Free Radical and Antioxidant Heath, Department of Environmental Health, University of Pittsburgh, USA; Laboratory of Navigational Redox Lipidomics and Department of Human Pathology, IM Sechenov Moscow State Medical University, Russian Federation; Departments of Chemistry, University of Pittsburgh, USA; Departments of Pharmacology and Chemical Biology, University of Pittsburgh, USA; Departments of Radiation Oncology, University of Pittsburgh, USA.
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29
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Syiemlieh I, Asthana M, Asthana SK, Kurbah SD, Koch A, Lal RA. Water soluble new bimetallic catalyst [CuZn(bz)3(bpy)2]PF6 in hydrogen peroxide mediated oxidation of alcohols to aldehydes/ketones and C-N functional groups. J Organomet Chem 2018. [DOI: 10.1016/j.jorganchem.2018.10.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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30
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Lu HF, Chen HF, Kao CL, Chao I, Chen HY. A computational study of the Fenton reaction in different pH ranges. Phys Chem Chem Phys 2018; 20:22890-22901. [DOI: 10.1039/c8cp04381g] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The mechanism of the Fenton reaction is pH dependent and four distinct reactive species have been identified and found to display quite different oxidation reactivities.
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Affiliation(s)
- Hsiu-Feng Lu
- Institute of Chemistry
- Academia Sinica
- Taipei 11529
- Taiwan
| | - Hui-Fen Chen
- Department of Medicinal and Applied Chemistry
- Kaohsiung Medical University
- Kaohsiung 80708
- Taiwan
| | - Chai-Lin Kao
- Department of Medicinal and Applied Chemistry
- Kaohsiung Medical University
- Kaohsiung 80708
- Taiwan
| | - Ito Chao
- Institute of Chemistry
- Academia Sinica
- Taipei 11529
- Taiwan
| | - Hsing-Yin Chen
- Department of Medicinal and Applied Chemistry
- Kaohsiung Medical University
- Kaohsiung 80708
- Taiwan
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31
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Castillo RG, Banerjee R, Allpress CJ, Rohde GT, Bill E, Que L, Lipscomb JD, DeBeer S. High-Energy-Resolution Fluorescence-Detected X-ray Absorption of the Q Intermediate of Soluble Methane Monooxygenase. J Am Chem Soc 2017; 139:18024-18033. [PMID: 29136468 PMCID: PMC5729100 DOI: 10.1021/jacs.7b09560] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Kα high-energy-resolution fluorescence detected X-ray absorption spectroscopy (HERFD XAS) provides a powerful tool for overcoming the limitations of conventional XAS to identify the electronic structure and coordination environment of metalloprotein active sites. Herein, Fe Kα HERFD XAS is applied to the diiron active site of soluble methane monooxygenase (sMMO) and to a series of high-valent diiron model complexes, including diamond-core [FeIV2(μ-O)2(L)2](ClO4)4] (3) and open-core [(O═FeIV-O-FeIV(OH)(L)2](ClO4)3 (4) models (where, L = tris(3,5-dimethyl-4-methoxypyridyl-2-methyl)amine) (TPA*)). Pronounced differences in the HERFD XAS pre-edge energies and intensities are observed for the open versus closed Fe2O2 cores in the model compounds. These differences are reproduced by time-dependent density functional theory (TDDFT) calculations and allow for the pre-edge energies and intensity to be directly correlated with the local active site geometric and electronic structure. A comparison of the model complex HERFD XAS data to that of MMOHQ (the key intermediate in methane oxidation) is supportive of an open-core structure. Specifically, the large pre-edge area observed for MMOHQ may be rationalized by invoking an open-core structure with a terminal FeIV═O motif, though further modulations of the core structure due to the protein environment cannot be ruled out. The present study thus motivates the need for additional experimental and theoretical studies to unambiguously assess the active site conformation of MMOHQ.
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Affiliation(s)
- Rebeca G. Castillo
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34, D-45470 Mülheim an der Ruhr, Germany
| | - Rahul Banerjee
- Department of Biochemistry, Molecular Biology and Biophysics, 321 Church St. SE, Minneapolis, MN 55455
| | - Caleb J. Allpress
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455
| | - Gregory T. Rohde
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455
| | - Eckhard Bill
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34, D-45470 Mülheim an der Ruhr, Germany
| | - Lawrence Que
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, MN 55455
| | - John D. Lipscomb
- Department of Biochemistry, Molecular Biology and Biophysics, 321 Church St. SE, Minneapolis, MN 55455
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34, D-45470 Mülheim an der Ruhr, Germany
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32
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Bernasconi L, Kazaryan A, Belanzoni P, Baerends EJ. Catalytic Oxidation of Water with High-Spin Iron(IV)–Oxo Species: Role of the Water Solvent. ACS Catal 2017. [DOI: 10.1021/acscatal.7b00568] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Leonardo Bernasconi
- STFC
Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX, United Kingdom
| | - Andranik Kazaryan
- Theoretical
Chemistry Section, Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands
| | - Paola Belanzoni
- Department
of Chemistry, Biology and Biotechnology, University of Perugia and Institute of Molecular Science and Technologies (ISTM-CNR), Via Elce
di Sotto 8, I-06123 Perugia, Italy
| | - Evert Jan Baerends
- Theoretical
Chemistry Section, Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands
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33
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Shen LQ, Kundu S, Collins TJ, Bominaar EL. Analysis of Hydrogen Atom Abstraction from Ethylbenzene by an FeVO(TAML) Complex. Inorg Chem 2017; 56:4347-4356. [DOI: 10.1021/acs.inorgchem.6b02796] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Longzhu Q. Shen
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Soumen Kundu
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Terrence J. Collins
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Emile L. Bominaar
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
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34
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Zhu Y, Ksibe AZ, Schäfer H, Blindauer CA, Bugg TDH, Chen Y. O2-independent demethylation of trimethylamineN-oxide by Tdm ofMethylocella silvestris. FEBS J 2016; 283:3979-3993. [DOI: 10.1111/febs.13902] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 09/09/2016] [Accepted: 09/15/2016] [Indexed: 12/11/2022]
Affiliation(s)
- Yijun Zhu
- School of Life Sciences; University of Warwick; Coventry UK
| | - Amira Z. Ksibe
- Department of Chemistry; University of Warwick; Coventry UK
| | | | | | | | - Yin Chen
- School of Life Sciences; University of Warwick; Coventry UK
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35
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A growing family of O2 activating dinuclear iron enzymes with key catalytic diiron(III)-peroxo intermediates: Biological systems and chemical models. Coord Chem Rev 2016. [DOI: 10.1016/j.ccr.2016.05.014] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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36
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Dutta AK, Samanta S, Dutta S, Lucas CR, Dawe LN, Biswas P, Adhikary B. Iron(III) complexes of 2-(1H-benzo[d]imidazol-2-yl)phenol and acetate or nitrate as catalysts for epoxidation of olefins with hydrogen peroxide. J Mol Struct 2016. [DOI: 10.1016/j.molstruc.2016.02.101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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37
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Srinivas BTV, Rawat VS, Sreedhar B. Iron-Catalyzed Dioxygenation of Alkenes and Terminal Alkynes by using (Diacetoxyiodo)benzene as Oxidant. Adv Synth Catal 2015. [DOI: 10.1002/adsc.201500681] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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38
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Liu S, Jung J, Ohkubo K, Hicks SD, Bougher CJ, Abu-Omar MM, Fukuzumi S. Activationless Electron Self-Exchange of High-Valent Oxo and Imido Complexes of Chromium Corroles. Inorg Chem 2015; 54:9223-8. [DOI: 10.1021/acs.inorgchem.5b01777] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Shuo Liu
- Brown Laboratory and Department of Chemistry, Purdue University, 560
Oval Drive, West Lafayette, Indiana 47907, United States
| | - Jieun Jung
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Korea
| | - Kei Ohkubo
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Korea
- Department of Material and Life Science, Graduate School
of Engineering, Osaka University, ALCA and SENTAN, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871, Japan
| | - Scott D. Hicks
- Brown Laboratory and Department of Chemistry, Purdue University, 560
Oval Drive, West Lafayette, Indiana 47907, United States
| | - Curt J. Bougher
- Brown Laboratory and Department of Chemistry, Purdue University, 560
Oval Drive, West Lafayette, Indiana 47907, United States
| | - Mahdi M. Abu-Omar
- Brown Laboratory and Department of Chemistry, Purdue University, 560
Oval Drive, West Lafayette, Indiana 47907, United States
| | - Shunichi Fukuzumi
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Korea
- Department of Material and Life Science, Graduate School
of Engineering, Osaka University, ALCA and SENTAN, Japan Science and Technology Agency (JST), Suita, Osaka 565-0871, Japan
- Faculty of Science and Engineering, Meijo University, ALCA and SENTAN, Japan Science and Technology Agency (JST), Nagoya, Aichi 468-0073, Japan
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39
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Rana S, Dey A, Maiti D. Mechanistic elucidation of C-H oxidation by electron rich non-heme iron(IV)-oxo at room temperature. Chem Commun (Camb) 2015; 51:14469-72. [PMID: 26277913 DOI: 10.1039/c5cc04803f] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Non-heme iron(IV)-oxo species form iron(III) intermediates during hydrogen atom abstraction (HAA) from the C-H bond. While synthesizing a room temperature stable, electron rich, non-heme iron(IV)-oxo compound, we obtained iron(III)-hydroxide, iron(III)-alkoxide and hydroxylated-substrate-bound iron(II) as the detectable intermediates. The present study revealed that a radical rebound pathway was operative for benzylic C-H oxidation of ethylbenzene and cumene. A dissociative pathway for cyclohexane oxidation was established based on UV-vis and radical trap experiments. Interestingly, experimental evidence including O-18 labeling and mechanistic study suggested an electron transfer mechanism to be operative during C-H oxidation of alcohols (e.g. benzyl alcohol and cyclobutanol). The present report, therefore, unveils non-heme iron(IV)-oxo promoted substrate-dependent C-H oxidation pathways which are of synthetic as well as biological significance.
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Affiliation(s)
- Sujoy Rana
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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40
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Mitra M, Nimir H, Demeshko S, Bhat SS, Malinkin SO, Haukka M, Lloret-Fillol J, Lisensky GC, Meyer F, Shteinman AA, Browne WR, Hrovat DA, Richmond MG, Costas M, Nordlander E. Nonheme Fe(IV) Oxo Complexes of Two New Pentadentate Ligands and Their Hydrogen-Atom and Oxygen-Atom Transfer Reactions. Inorg Chem 2015. [PMID: 26198840 DOI: 10.1021/ic5029564] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Two new pentadentate {N5} donor ligands based on the N4Py (N4Py = N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine) framework have been synthesized, viz. [N-(1-methyl-2-benzimidazolyl)methyl-N-(2-pyridyl)methyl-N-(bis-2-pyridyl methyl)amine] (L(1)) and [N-bis(1-methyl-2-benzimidazolyl)methyl-N-(bis-2-pyridylmethyl)amine] (L(2)), where one or two pyridyl arms of N4Py have been replaced by corresponding (N-methyl)benzimidazolyl-containing arms. The complexes [Fe(II)(CH3CN)(L)](2+) (L = L(1) (1); L(2) (2)) were synthesized, and reaction of these ferrous complexes with iodosylbenzene led to the formation of the ferryl complexes [Fe(IV)(O)(L)](2+) (L = L(1) (3); L(2) (4)), which were characterized by UV-vis spectroscopy, high resolution mass spectrometry, and Mössbauer spectroscopy. Complexes 3 and 4 are relatively stable with half-lives at room temperature of 40 h (L = L(1)) and 2.5 h (L = L(2)). The redox potentials of 1 and 2, as well as the visible spectra of 3 and 4, indicate that the ligand field weakens as ligand pyridyl substituents are progressively substituted by (N-methyl)benzimidazolyl moieties. The reactivities of 3 and 4 in hydrogen-atom transfer (HAT) and oxygen-atom transfer (OAT) reactions show that both complexes exhibit enhanced reactivities when compared to the analogous N4Py complex ([Fe(IV)(O)(N4Py)](2+)), and that the normalized HAT rates increase by approximately 1 order of magnitude for each replacement of a pyridyl moiety; i.e., [Fe(IV)(O)(L(2))](2+) exhibits the highest rates. The second-order HAT rate constants can be directly related to the substrate C-H bond dissociation energies. Computational modeling of the HAT reactions indicates that the reaction proceeds via a high spin transition state.
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Affiliation(s)
- Mainak Mitra
- †Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-221 00, Lund, Sweden
| | - Hassan Nimir
- ‡Department of Chemistry and Earth Sciences, College of Arts and Sciences, Qatar University, P.O. Box 2713, Doha, State of Qatar
| | - Serhiy Demeshko
- §Institute of Inorganic Chemistry, Georg-August-University Göttingen, Tammanstrasse 4, D-37077 Göttingen, Germany
| | - Satish S Bhat
- †Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-221 00, Lund, Sweden
| | - Sergey O Malinkin
- †Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-221 00, Lund, Sweden
| | - Matti Haukka
- ⊥Department of Chemistry, University of Jyväskylä, P.O. Box-35, Jyväskylä, FI-40014, Finland
| | - Julio Lloret-Fillol
- ¶QBIS, Department of Chemistry, University de Girona, Campus Montilivi, E-17071 Girona, Spain
| | - George C Lisensky
- ∥Department of Chemistry, Beloit College, 700 College Street, Beloit, Wisconsin 53511, United States
| | - Franc Meyer
- §Institute of Inorganic Chemistry, Georg-August-University Göttingen, Tammanstrasse 4, D-37077 Göttingen, Germany
| | - Albert A Shteinman
- #Institute of Problems of Chemical Physics, Chernogolovka, Moscow District, 142432, Russian Federation
| | - Wesley R Browne
- ∇Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - David A Hrovat
- ○Center for Advanced Scientific Computing and Modeling, University of North Texas, Denton, Texas 76203, United States.,◆Department of Chemistry, University of North Texas, Denton, Texas 76203, United States
| | - Michael G Richmond
- ◆Department of Chemistry, University of North Texas, Denton, Texas 76203, United States
| | - Miquel Costas
- ¶QBIS, Department of Chemistry, University de Girona, Campus Montilivi, E-17071 Girona, Spain
| | - Ebbe Nordlander
- †Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-221 00, Lund, Sweden
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41
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Ansari A, Rajaraman G. ortho-Hydroxylation of aromatic acids by a non-heme Fe(V)=O species: how important is the ligand design? Phys Chem Chem Phys 2015; 16:14601-13. [PMID: 24812659 DOI: 10.1039/c3cp55430a] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
There is a growing interest in probing the mechanism of catalytic transformations effected by non-heme iron-oxo complexes as these reactions set a platform for understanding the relevant enzymatic reactions. The ortho-hydroxylation of aromatic compounds is one such reaction catalysed by iron-oxo complexes. Experimentally [Fe(II)(BPMEN)(CH3CN)2](2+) (1) and [Fe(II)(TPA)(CH3CN)2](2+) (2) (where TPA = tris(2-pyridylmethyl)amine and BPMEN = N,N′-dimethyl-N,N′-bis(2-pyridylmethyl)ethane-1,2-diamine) complexes containing amino pyridine ligands along with H2O2 are employed to carry out these transformations where complex 1 is found to be more reactive than complex 2. Herein, using density functional methods employing B3LYP and dispersion corrected B3LYP (B3LYP-D) functionals, we have explored the mechanism of this reaction to reason out the importance of ligand design in fine-tuning the reactivity of such catalytic transformations. Dispersion corrected B3LYP is found to be superior to B3LYP in predicting the correct ground state of these species and also yields lower barrier heights than the B3LYP functional. Starting the reaction from the Fe(III)–OOH species, both homolytic and heterolytic cleavage of the O···O bond is explored leading to the formation of the transient Fe(IV)=O and Fe(V)=O species. For both the ligand systems, heterolytic cleavage was energetically preferable and our calculations suggest that both the reactions are catalyzed by an elusive high-valent Fe(V)=O species. The Fe(V)=O species undergoes the reaction via an electrophilic attack of the benzene ring to effect the ortho-hydroxylation reaction. The reactivity pattern observed for 1 and 2 are reflected in the computed barrier heights for the ortho-hydroxylation reaction. Electronic structure analysis reveals that the difference in reactivity between the ligand architectures described in complex 1 and 2 arise due to orientation of the pyridine ring(s) parallel or perpendicular to the Fe(V)=O bond. The parallel orientation of the pyridine ring is found to mix with the (πFe(dyz)–O(py))* orbital of the Fe-oxo bond leading to a reduction in the electrophilicity of the ferryl oxygen atom. Our calculations highlight the importance of ligand design in this chemistry and suggest that this concept can be used to (i) stabilize high-valent intermediates which can be trapped and thoroughly characterized (ii) enhance the reactivity and efficiency of the oxidants by increasing the electrophilicity of the ferryl oxygen containing FeVO species. Our computed results are in general agreement with the experimental results.
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Affiliation(s)
- Azaj Ansari
- Department of Chemistry, Indian Institute of Technology-Bombay, Powai, Mumbai, India.
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Mandal D, Ramanan R, Usharani D, Janardanan D, Wang B, Shaik S. How does tunneling contribute to counterintuitive H-abstraction reactivity of nonheme Fe(IV)O oxidants with alkanes? J Am Chem Soc 2015; 137:722-33. [PMID: 25513834 DOI: 10.1021/ja509465w] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
This article addresses the intriguing hydrogen-abstraction (H-abstraction) and oxygen-transfer (O-transfer) reactivity of a series of nonheme [Fe(IV)(O)(TMC)(Lax)](z+) complexes, with a tetramethyl cyclam ligand and a variable axial ligand (Lax), toward three substrates: 1,4-cyclohexadiene, 9,10-dihydroanthracene, and triphenyl phosphine. Experimentally, O-transfer-reactivity follows the relative electrophilicity of the complexes, whereas the corresponding H-abstraction-reactivity generally increases as the axial ligand becomes a better electron donor, hence exhibiting an antielectrophilic trend. Our theoretical results show that the antielectrophilic trend in H-abstraction is affected by tunneling contributions. Room-temperature tunneling increases with increase of the electron donation power of the axial-ligand, and this reverses the natural electrophilic trend, as revealed through calculations without tunneling, and leads to the observed antielectrophilic trend. By contrast, O-transfer-reactivity, not being subject to tunneling, retains an electrophilic-dependent reactivity trend, as revealed experimentally and computationally. Tunneling-corrected kinetic-isotope effect (KIE) calculations matched the experimental KIE values only if all of the H-abstraction reactions proceeded on the quintet state (S = 2) surface. As such, the present results corroborate the initially predicted two-state reactivity (TSR) scenario for these reactions. The increase of tunneling with the electron-releasing power of the axial ligand, and the reversal of the "natural" reactivity pattern, support the "tunneling control" hypothesis (Schreiner et al., ref 19). Should these predictions be corroborated, the entire field of C-H bond activation in bioinorganic chemistry would lay open to reinvestigation.
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Affiliation(s)
- Debasish Mandal
- Institute of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, The Hebrew University of Jerusalem , 91904 Jerusalem, Israel
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Ansari M, Vyas N, Ansari A, Rajaraman G. Oxidation of methane by an N-bridged high-valent diiron–oxo species: electronic structure implications on the reactivity. Dalton Trans 2015; 44:15232-43. [DOI: 10.1039/c5dt01060h] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Methane activation by dinuclear high-valent iron–oxo species: do we need two metals to activate such inert bonds? Our theoretical study using DFT methods where electronic structure details and mechanistic aspects are established answers this intriguing question.
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Affiliation(s)
- Mursaleem Ansari
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai-400076
- India
| | - Nidhi Vyas
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai-400076
- India
| | - Azaj 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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Dai W, Lv Y, Wang L, Shang S, Chen B, Li G, Gao S. Highly efficient oxidation of alcohols catalyzed by a porphyrin-inspired manganese complex. Chem Commun (Camb) 2015; 51:11268-71. [DOI: 10.1039/c5cc03657g] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A novel strategy for catalytic oxidation of a variety of benzylic, allylic, propargylic, and aliphatic alcohols to the corresponding aldehydes or ketones has been successfully developed.
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Affiliation(s)
- Wen Dai
- Dalian Institute of Chemical Physics
- The Chinese Academy of Sciences and Dalian National Laboratory for Clean Energy
- Dalian 116023
- China
| | - Ying Lv
- Dalian Institute of Chemical Physics
- The Chinese Academy of Sciences and Dalian National Laboratory for Clean Energy
- Dalian 116023
- China
| | - Lianyue Wang
- Dalian Institute of Chemical Physics
- The Chinese Academy of Sciences and Dalian National Laboratory for Clean Energy
- Dalian 116023
- China
| | - Sensen Shang
- Dalian Institute of Chemical Physics
- The Chinese Academy of Sciences and Dalian National Laboratory for Clean Energy
- Dalian 116023
- China
| | - Bo Chen
- Dalian Institute of Chemical Physics
- The Chinese Academy of Sciences and Dalian National Laboratory for Clean Energy
- Dalian 116023
- China
| | - Guosong Li
- Dalian Institute of Chemical Physics
- The Chinese Academy of Sciences and Dalian National Laboratory for Clean Energy
- Dalian 116023
- China
| | - Shuang Gao
- Dalian Institute of Chemical Physics
- The Chinese Academy of Sciences and Dalian National Laboratory for Clean Energy
- Dalian 116023
- China
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Marsh BM, Zhou J, Garand E. Charge transfer in MOH(H2O)+ (M = Mn, Fe, Co, Ni, Cu, Zn) complexes revealed by vibrational spectroscopy of mass-selected ions. Phys Chem Chem Phys 2015; 17:25786-92. [DOI: 10.1039/c5cp01522g] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The hydroxide frequency in MOH(H2O)+ is a sensitive probe of charge transfer.
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Affiliation(s)
- Brett M. Marsh
- Department of Chemistry
- University of Wisconsin-Madison
- Madison
- USA
| | - Jia Zhou
- Department of Chemistry
- University of Wisconsin-Madison
- Madison
- USA
| | - Etienne Garand
- Department of Chemistry
- University of Wisconsin-Madison
- Madison
- USA
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Stuart D, Tecmer P, Ayers PW, Boguslawski K. The effect of nitrido, azide, and nitrosyl ligands on magnetization densities and magnetic properties of iridium PNP pincer-type complexes. RSC Adv 2015. [DOI: 10.1039/c5ra17507k] [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] Open
Abstract
The magnetisation density of different iridium PNP pincer-type complexes depends on the chosen quantum chemistry method.
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Affiliation(s)
- Daniel Stuart
- Department of Chemistry and Chemical Biology
- McMaster University
- Hamilton
- Canada
- Department of Chemistry and Biochemistry
| | - Paweł Tecmer
- Department of Chemistry and Chemical Biology
- McMaster University
- Hamilton
- Canada
- Institute of Physics, Faculty of Physics, Astronomy and Informatics
| | - Paul W. Ayers
- Department of Chemistry and Chemical Biology
- McMaster University
- Hamilton
- Canada
| | - Katharina Boguslawski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics
- Nicolaus Copernicus University
- 87-100 Toruń
- Poland
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Shen D, Miao C, Xu D, Xia C, Sun W. Highly Efficient Oxidation of Secondary Alcohols to Ketones Catalyzed by Manganese Complexes of N4 Ligands with H2O2. Org Lett 2014; 17:54-7. [DOI: 10.1021/ol5032156] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Duyi Shen
- State Key
Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute
of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Chengxia Miao
- State Key
Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute
of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, P. R. China
| | - Daqian Xu
- State Key
Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute
of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, P. R. China
| | - Chungu Xia
- State Key
Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute
of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, P. R. China
| | - Wei Sun
- State Key
Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute
of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, P. R. China
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Geng C, Ye S, Neese F. Does a higher metal oxidation state necessarily imply higher reactivity toward H-atom transfer? A computational study of C-H bond oxidation by high-valent iron-oxo and -nitrido complexes. Dalton Trans 2014; 43:6079-86. [PMID: 24492533 DOI: 10.1039/c3dt53051e] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In this work, the reactions of C-H bond activation by two series of iron-oxo ( (Fe(IV)), (Fe(V)), (Fe(VI))) and -nitrido model complexes ( (Fe(IV)), (Fe(V)), (Fe(VI))) with a nearly identical coordination geometry but varying iron oxidation states ranging from iv to vi were comprehensively investigated using density functional theory. We found that in a distorted octahedral coordination environment, the iron-oxo species and their isoelectronic nitrido analogues feature totally different intrinsic reactivities toward C-H bond cleavage. In the case of the iron-oxo complexes, the reaction barrier monotonically decreases as the iron oxidation state increases, consistent with the gradually enhanced electrophilicity across the series. The iron-nitrido complex is less reactive than its isoelectronic iron-oxo species, and more interestingly, a counterintuitive reactivity pattern was observed, i.e. the activation barriers essentially remain constant independent of the iron oxidation states. The detailed analysis using the Polanyi principle demonstrates that the different reactivities between these two series originate from the distinct thermodynamic driving forces, more specifically, the bond dissociation energies (BDEE-Hs, E = O, N) of the nascent E-H bonds in the FeE-H products. Further decomposition of the BDEE-Hs into the electron and proton affinity components shed light on how the oxidation states modulate the BDEE-Hs of the two series.
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Affiliation(s)
- Caiyun Geng
- Max-Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, D-45470 Mülheim an der Ruhr, Germany.
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Torres-Alacan J, Vöhringer P. Generating high-valent iron with light: photochemical dynamics from femtoseconds to seconds. INT REV PHYS CHEM 2014. [DOI: 10.1080/0144235x.2014.973197] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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