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Pal P, Schafer MC, Hendrich MP, Ryabov AD, Collins TJ. The Mechanism of Formation of Active Fe-TAMLs Using HClO Enlightens Design for Maximizing Catalytic Activity at Environmentally Optimal, Circumneutral pH. Inorg Chem 2023; 62:5586-5592. [PMID: 36967523 PMCID: PMC10091481 DOI: 10.1021/acs.inorgchem.3c00104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2023]
Abstract
Fe-TAML/peroxide catalysis provides simple, powerful, ultradilute approaches for removing micropollutants from water. The typically rate-determining interactions of H2O2 with Fe-TAMLs (rate constant kI) are sharply pH-sensitive with rate maxima in the pH 9-10 window. Fe-TAML design or process design that shifts the maximum rates to the pH 6-8 window of most wastewaters would make micropollutant eliminations even more powerful. Here, we show how the different pH dependencies of the interactions of Fe-TAMLs with peroxide or hypochlorite to form active Fe-TAMLs (kI step) illuminate why moving from H2O2 (pKa, ca. 11.6) to hypochlorite (pKa, 7.5) shifts the pH of the fastest catalysis to as low as 8.2. At pH 7, hypochlorite catalysis is 100-1000 times faster than H2O2 catalysis. The pH of maximum catalytic activity is also moderated by the pKa's of the Fe-TAML axial water ligands, 8.8, 9.3, and 10.3, respectively, for [Fe{4-NO2C6H3-1,2-(NCOCMe2NSO2)2CHMe}(H2O)n]- (2) [n = 1-2], [Fe{4-NO2C6H3-1,2-(NCOCMe2NCO)2CF2}(H2O)n]- (1b), and [Fe{C6H4-1,2-(NCOCMe2NCO)2CMe2}(H2O)n]- (1a). The new bis(sulfonamido)-bis(carbonamido)-ligated 2 exhibits the lowest pKa and delivers the largest hypochlorite over peroxide catalytic rate advantage. The fast Fe-TAML/hypochlorite catalysis is accompanied by slow noncatalytic oxidations of Orange II.
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2
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Li XX, Lu X, Park JW, Cho KB, Nam W. Nonheme Iron Imido Complexes Bearing a Non-Innocent Ligand: A Synthetic Chameleon Species in Oxidation Reactions. Chemistry 2021; 27:17495-17503. [PMID: 34590742 DOI: 10.1002/chem.202103295] [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: 09/10/2021] [Indexed: 11/07/2022]
Abstract
High-valent iron-imido complexes can perform C-H activation and sulfimidation reactions, but are far less studied than the more ubiquitous iron-oxo species. As case studies, we have looked at a recently published iron(V)-imido ligand π-cation radical complex, which is formally an iron(VI)-imido complex [FeV (NTs)(TAML+. )] (1; NTs=tosylimido), and an iron(V)-imido complex [FeV (NTs)(TAML)]- (2). Using a theoretical approach, we found that they have multiple energetically close-lying electromers, sometimes even without changing spin states, reminiscent of the so-called Compound I in Cytochrome P450. When studying their reactivity theoretically, it is indeed found that their electronic structures may change to perform efficient oxidations, emulating the multi-spin state reactivity in FeIV O systems. This is actually in contrast to the known [FeV (O)(TAML)]- species (3), where the reactions occur only on the ground spin state. We also looked into the whole reaction pathway for the C-H bond activation of 1,4-cyclohexadiene by these intermediates to reproduce the experimentally observed products, including steps that usually attract no interest (neither theoretically nor experimentally) due to their non-rate-limiting status and fast reactivity. A new "clustering non-rebound mechanism" is presented for this C-H activation reaction.
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Affiliation(s)
- Xiao-Xi Li
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul, 03760, Korea
| | - Xiaoyan Lu
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul, 03760, Korea
| | - Jae Woo Park
- Department of Chemistry, Chungbuk National University, Cheongju, 28644, Korea
| | - Kyung-Bin Cho
- Department of Chemistry, Jeonbuk National University, Jeonju, 54896, Korea
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul, 03760, Korea
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3
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Sharma N, Lee Y, Nam W, Fukuzumi S. Photoinduced Generation of Superoxidants for the Oxidation of Substrates with High C−H Bond Dissociation Energies. CHEMPHOTOCHEM 2019. [DOI: 10.1002/cptc.201900219] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Namita Sharma
- Department of Chemistry and Nano ScienceEwha Womans University Seoul 03760 Korea
| | - Yong‐Min Lee
- Department of Chemistry and Nano ScienceEwha Womans University Seoul 03760 Korea
| | - Wonwoo Nam
- Department of Chemistry and Nano ScienceEwha Womans University Seoul 03760 Korea
| | - Shunichi Fukuzumi
- Department of Chemistry and Nano ScienceEwha Womans University Seoul 03760 Korea
- Graduate School of Science and EngineeringMeijo University, Nagoya Aichi 468-8502 Japan
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4
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Somasundar Y, Shen LQ, Hoane AG, Tang LL, Mills MR, Burton AE, Ryabov AD, Collins TJ. Structural, Mechanistic, and Ultradilute Catalysis Portrayal of Substrate Inhibition in the TAML–Hydrogen Peroxide Catalytic Oxidation of the Persistent Drug and Micropollutant, Propranolol. J Am Chem Soc 2018; 140:12280-12289. [DOI: 10.1021/jacs.8b08108] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Yogesh Somasundar
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Longzhu Q. Shen
- Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, U.K
| | - Alexis G. Hoane
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Liang L. Tang
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Matthew R. Mills
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Abigail E. Burton
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Alexander D. Ryabov
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Terrence J. Collins
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
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5
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Sharma N, Jung J, Ohkubo K, Lee YM, El-Khouly ME, Nam W, Fukuzumi S. Long-Lived Photoexcited State of a Mn(IV)-Oxo Complex Binding Scandium Ions That is Capable of Hydroxylating Benzene. J Am Chem Soc 2018; 140:8405-8409. [PMID: 29906116 DOI: 10.1021/jacs.8b04904] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Photoexcitation of a MnIV-oxo complex binding scandium ions ([(Bn-TPEN)MnIV(O)]2+-(Sc(OTf)3)2) in a solvent mixture of trifluoroethanol and acetonitrile (v/v = 1:1) resulted in formation of the long-lived photoexcited state, which can hydroxylate benzene to phenol. The photohydroxylation of benzene by [(Bn-TPEN)MnIV(O)]2+-(Sc(OTf)3)2 was made possible by electron transfer from benzene to the long-lived 2 E excited state of [(Bn-TPEN)MnIV(O)]2+-(Sc(OTf)3)2 to produce a benzene radical cation, which reacted with water as revealed by laser-induced transient absorption measurements.
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Affiliation(s)
- Namita Sharma
- Department of Chemistry and Nano Science , Ewha Womans University , Seoul 03760 , Korea
| | - Jieun Jung
- Department of Chemistry and Nano Science , Ewha Womans University , Seoul 03760 , Korea.,Department of Chemistry, Graduate School of Science , Nagoya University , Chikusa , Nagoya 464-8602 , Japan
| | - Kei Ohkubo
- Department of Chemistry and Nano Science , Ewha Womans University , Seoul 03760 , Korea.,Institute for Advanced Co-Creation Studies , Osaka University , Suita , Osaka 565-0871 , Japan.,Open and Transdisciplinary Research Initiatives , Osaka University , Suita , Osaka 565-0871 , Japan
| | - Yong-Min Lee
- Department of Chemistry and Nano Science , Ewha Womans University , Seoul 03760 , Korea
| | - Mohamed E El-Khouly
- Department of Chemistry and Nano Science , Ewha Womans University , Seoul 03760 , Korea.,Department of Chemistry, Faculty of Science , Kafrelsheikh University , Kafrelsheikh 33516 , Egypt
| | - Wonwoo Nam
- Department of Chemistry and Nano Science , Ewha Womans University , Seoul 03760 , Korea.,School of Chemistry and Chemical Engineering , Shaanxi Normal University , Xi'an 710119 , People's Republic of China
| | - Shunichi Fukuzumi
- Department of Chemistry and Nano Science , Ewha Womans University , Seoul 03760 , Korea.,Faculty of Science and Engineering , Meijo University, SENTAN, Japan Science and Technology Agency (JST) , Nagoya , Aichi 468-0073 , Japan
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6
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Mills MR, Shen LQ, Zhang DZ, Ryabov AD, Collins TJ. Iron(III) Ejection from a “Beheaded” TAML Activator: Catalytically Relevant Mechanistic Insight into the Deceleration of Electrophilic Processes by Electron Donors. Inorg Chem 2017; 56:10226-10234. [DOI: 10.1021/acs.inorgchem.7b00921] [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)
- Matthew R. Mills
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Longzhu Q. Shen
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - David Z. Zhang
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Alexander D. Ryabov
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Terrence J. Collins
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
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7
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Collins TJ, Ryabov AD. Targeting of High-Valent Iron-TAML Activators at Hydrocarbons and Beyond. Chem Rev 2017; 117:9140-9162. [PMID: 28488444 DOI: 10.1021/acs.chemrev.7b00034] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
TAML activators of peroxides are iron(III) complexes. The ligation by four deprotonated amide nitrogens in macrocyclic motifs is the signature of TAMLs where the macrocyclic structures vary considerably. TAML activators are exceptional functional replicas of the peroxidases and cytochrome P450 oxidizing enzymes. In water, they catalyze peroxide oxidation of a broad spectrum of compounds, many of which are micropollutants, compounds that produce undesired effects at low concentrations-as with the enzymes, peroxide is typically activated with near-quantitative efficiency. In nonaqueous solvents such as organic nitriles, the prototype TAML activator gave the structurally authenticated reactive iron(V)oxo units (FeVO), wherein the iron atom is two oxidation equivalents above the FeIII resting state. The iron(V) state can be achieved through the intermediacy of iron(IV) species, which are usually μ-oxo-bridged dimers (FeIVFeIV), and this allows for the reactivity of this potent reactive intermediate to be studied in stoichiometric processes. The present review is primarily focused at the mechanistic features of the oxidation by FeVO of hydrocarbons including cyclohexane. The main topic is preceded by a description of mechanisms of oxidation of thioanisoles by FeVO, because the associated studies provide valuable insight into the ability of FeVO to oxidize organic molecules. The review is opened by a summary of the interconversions between FeIII, FeIVFeIV, and FeVO species, since this information is crucial for interpreting the kinetic data. The highest reactivity in both reaction classes described belongs to FeVO. The resting state FeIII is unreactive oxidatively. Intermediate reactivity is typically found for FeIVFeIV; therefore, kinetic features for these species in interchange and oxidation processes are also reviewed. Examples of using TAML activators for C-H bond cleavage applied to fine organic synthesis conclude the review.
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Affiliation(s)
- Terrence J Collins
- Department of Chemistry, Carnegie Mellon University , 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Alexander D Ryabov
- Department of Chemistry, Carnegie Mellon University , 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
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8
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Gupta R, Li XX, Cho KB, Guo M, Lee YM, Wang Y, Fukuzumi S, Nam W. Tunneling Effect That Changes the Reaction Pathway from Epoxidation to Hydroxylation in the Oxidation of Cyclohexene by a Compound I Model of Cytochrome P450. J Phys Chem Lett 2017; 8:1557-1561. [PMID: 28301931 DOI: 10.1021/acs.jpclett.7b00461] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The rate constants of the C═C epoxidation and the C-H hydroxylation (i.e., allylic C-H bond activation) in the oxidation of cyclohexene by a high-valent iron(IV)-oxo porphyrin π-cation radical complex, [(TMP•+)FeIV(O)(Cl)] (1, TMP = meso-tetramesitylporphyrin dianion), were determined at various temperatures by analyzing the overall rate constants and the products obtained in the cyclohexene oxidation by 1, leading us to conclude that reaction pathway changes from the C═C epoxidation to C-H hydroxylation by decreasing reaction temperature. When cyclohexene was replaced by deuterated cyclohexene (cyclohexene-d10), the epoxidation pathway dominated irrespective of the reaction temperature. The temperature dependence of the rate constant of the C-H hydroxylation pathway in the reactions of cyclohexene and cyclohexene-d10 by 1 suggests that there is a significant tunneling effect on the hydrogen atom abstraction of allylic C-H bonds of cyclohexene by 1, leading us to propose that the tunneling effect is a determining factor for the switchover of the reaction pathway from the C═C epoxidation pathway to the C-H hydroxylation pathway by decreasing reaction temperature. By performing density functional theory (DFT) calculations, the reaction energy barriers of the C═C epoxidation and C-H bond activation reactions by 1 were found to be similar, supporting the notion that small environmental changes, such as the reaction temperature, can flip the preference for one reaction to another.
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Affiliation(s)
- Ranjana Gupta
- Department of Chemistry and Nano Science, Ewha Womans University , Seoul 03760, Korea
| | - Xiao-Xi Li
- Department of Chemistry and Nano Science, Ewha Womans University , Seoul 03760, Korea
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Suzhou Research Institute of LICP, Lanzhou Institute of Chemical Physics (LICP), Chinese Academy of Sciences , Lanzhou 730000, China
| | - Kyung-Bin Cho
- Department of Chemistry and Nano Science, Ewha Womans University , Seoul 03760, Korea
| | - Mian Guo
- Department of Chemistry and Nano Science, Ewha Womans University , Seoul 03760, Korea
| | - Yong-Min Lee
- Department of Chemistry and Nano Science, Ewha Womans University , Seoul 03760, Korea
| | - Yong Wang
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Suzhou Research Institute of LICP, Lanzhou Institute of Chemical Physics (LICP), Chinese Academy of Sciences , Lanzhou 730000, China
| | - Shunichi Fukuzumi
- Department of Chemistry and Nano Science, Ewha Womans University , Seoul 03760, Korea
- Faculty of Science and Engineering, Meijo University, SENTAN, Japan Science and Technology Agency (JST) , Nagoya, Aichi 468-8502, Japan
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University , Seoul 03760, Korea
- State Key Laboratory for Oxo Synthesis and Selective Oxidation, Suzhou Research Institute of LICP, Lanzhou Institute of Chemical Physics (LICP), Chinese Academy of Sciences , Lanzhou 730000, China
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9
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High-valent metal-oxo complexes generated in catalytic oxidation reactions using water as an oxygen source. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2016.09.018] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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10
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Leto DF, Massie AA, Rice DB, Jackson TA. Spectroscopic and Computational Investigations of a Mononuclear Manganese(IV)-Oxo Complex Reveal Electronic Structure Contributions to Reactivity. J Am Chem Soc 2016; 138:15413-15424. [PMID: 27802057 DOI: 10.1021/jacs.6b08661] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The mononuclear Mn(IV)-oxo complex [MnIV(O)(N4py)]2+, where N4py is the pentadentate ligand N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine, has been proposed to attack C-H bonds by an excited-state reactivity pattern [ Cho, K.-B.; Shaik, S.; Nam, W. J. Phys. Chem. Lett. 2012 , 3 , 2851 - 2856 (DOI: 10.1021/jz301241z )]. In this model, a 4E excited state is utilized to provide a lower-energy barrier for hydrogen-atom transfer. This proposal is intriguing, as it offers both a rationale for the relatively high hydrogen-atom-transfer reactivity of [MnIV(O)(N4py)]2+ and a guideline for creating more reactive complexes through ligand modification. Here we employ a combination of electronic absorption and variable-temperature magnetic circular dichroism (MCD) spectroscopy to experimentally evaluate this excited-state reactivity model. Using these spectroscopic methods, in conjunction with time-dependent density functional theory (TD-DFT) and complete-active space self-consistent-field calculations (CASSCF), we define the ligand-field and charge-transfer excited states of [MnIV(O)(N4py)]2+. Through a graphical analysis of the signs of the experimental C-term MCD signals, we unambiguously assign a low-energy MCD feature of [MnIV(O)(N4py)]2+ as the 4E excited state predicted to be involved in hydrogen-atom-transfer reactivity. The CASSCF calculations predict enhanced MnIII-oxyl character on the excited-state 4E surface, consistent with previous DFT calculations. Potential-energy surfaces, developed using the CASSCF methods, are used to determine how the energies and wave functions of the ground and excited states evolved as a function of Mn═O distance. The unique insights into ground- and excited-state electronic structure offered by these spectroscopic and computational studies are harmonized with a thermodynamic model of hydrogen-atom-transfer reactivity, which predicts a correlation between transition-state barriers and driving force.
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Affiliation(s)
- Domenick F Leto
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas , Lawrence, Kansas 66045, United States
| | - Allyssa A Massie
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas , Lawrence, Kansas 66045, United States
| | - Derek B Rice
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas , Lawrence, Kansas 66045, United States
| | - Timothy A Jackson
- Department of Chemistry and Center for Environmentally Beneficial Catalysis, University of Kansas , Lawrence, Kansas 66045, United States
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11
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Yang T, Quesne MG, Neu HM, Cantú Reinhard FG, Goldberg DP, de Visser SP. Singlet versus Triplet Reactivity in an Mn(V)-Oxo Species: Testing Theoretical Predictions Against Experimental Evidence. J Am Chem Soc 2016; 138:12375-86. [PMID: 27545752 PMCID: PMC5228574 DOI: 10.1021/jacs.6b05027] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Discerning the factors that control the reactivity of high-valent metal-oxo species is critical to both an understanding of metalloenzyme reactivity and related transition metal catalysts. Computational studies have suggested that an excited higher spin state in a number of metal-oxo species can provide a lower energy barrier for oxidation reactions, leading to the conclusion that this unobserved higher spin state complex should be considered as the active oxidant. However, testing these computational predictions by experiment is difficult and has rarely been accomplished. Herein, we describe a detailed computational study on the role of spin state in the reactivity of a high-valent manganese(V)-oxo complex with para-Z-substituted thioanisoles and utilize experimental evidence to distinguish between the theoretical results. The calculations show an unusual change in mechanism occurs for the dominant singlet spin state that correlates with the electron-donating property of the para-Z substituent, while this change is not observed on the triplet spin state. Minimum energy crossing point calculations predict small spin-orbit coupling constants making the spin state change from low spin to high spin unlikely. The trends in reactivity for the para-Z-substituted thioanisole derivatives provide an experimental measure for the spin state reactivity in manganese-oxo corrolazine complexes. Hence, the calculations show that the V-shaped Hammett plot is reproduced by the singlet surface but not by the triplet state trend. The substituent effect is explained with valence bond models, which confirm a change from an electrophilic to a nucleophilic mechanism through a change of substituent.
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Affiliation(s)
- Tzuhsiung Yang
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Matthew G. Quesne
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Heather M. Neu
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Fabián G. Cantú Reinhard
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - David P. Goldberg
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Sam P. de Visser
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
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Fukuzumi S, Nam W. Thermal and photoinduced electron-transfer catalysis of high-valent metal-oxo porphyrins in oxidation of substrates. J PORPHYR PHTHALOCYA 2016. [DOI: 10.1142/s1088424616300032] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this manuscript, we have overviewed thermal and photoinduced electron transfer catalysis of high-valent metal-oxo porphyrins in oxidation of various substrates. The high-valent iron-oxo porphyrin in cytochrome P450 (P450) is produced by photoinduced electron transfer from electron donors, such as triethanolamine (TEOA), to the excited state of a photosensitizer such as eosin Y, followed by the reduction of the heme domain of P450 by the resulting radical anion of the photosensitizer and the subsequent reaction of the reduced heme with dioxygen (O[Formula: see text]. Various substrates were oxidized by O2 in this visible light-driven electron-transfer catalytic reaction with several P450s from bacteria and humans. A manganese(V)-oxo corrorazine was produced by photoinduced electron transfer from the excited state of manganese(III) corrorazine to O2, followed by hydrogen abstraction from toluene derivatives, catalyzing the oxidation of toluene derivatives with O2 in the presence of an acid via photoinduced electron transfer catalysis. High-valent manganese-oxo porphyrins are also produced by photoinduced electron transfer from the excited state of [Ru(bpy)3][Formula: see text] (bpy = 2,2′-bipyridine) to electron acceptors, followed by electron transfer oxidation of manganese(III) porphyrins with [Ru(bpy)3][Formula: see text], catalyzing oxidation of various substrates with O2. Finally photoinduced electron-transfer catalysis of cobalt porphyrins is discussed for the photocatalytic water oxidation with persulfate.
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Affiliation(s)
- Shunichi Fukuzumi
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Korea
- Faculty of Science and Engineering, ALCA and SENTAN, Japan Science and Technology Agency (JST), Meijo University, Nagoya, Aichi 468-0073, Japan
| | - Wonwoo Nam
- Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Korea
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13
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Peters KC, Comi TJ, Perry RH. Multistage Reactive Transmission-Mode Desorption Electrospray Ionization Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2015; 26:1494-1501. [PMID: 26091888 DOI: 10.1007/s13361-015-1171-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 04/16/2015] [Accepted: 04/18/2015] [Indexed: 06/04/2023]
Abstract
Elucidating reaction mechanisms is important for advancing many areas of science such as catalyst development. It is often difficult to probe fast reactions at ambient conditions with high temporal resolution. In addition, systems involving reagents that cross-react require analytical methods that can minimize interaction time and specify their order of introduction into the reacting system. Here, we explore the utility of transmission mode desorption electrospray ionization (TM-DESI) for reaction monitoring by directing a microdroplet spray towards a series of meshes with micrometer-sized openings coated with reagents, an approach we call multistage reactive TM-DESI (TM (n) -DESI, where n refers to the number of meshes; n = 2 in this report). Various stages of the reaction are initiated at each mesh surface, generating intermediates and products in microdroplet reaction vessels traveling towards the mass spectrometer. Using this method, we investigated the reactivity of iron porphyrin catalytic hydroxylation of propranolol and other substrates. Our experimental results indicate that TM (n) -DESI provides the ability to spatially separate reagents and control their order of introduction into the reacting system, thereby minimizing unwanted reactions that lead to catalyst deactivation and degradation products. In addition, comparison with DESI-MS analyses (the Zare and Latour laboratories published results suggesting accessible reaction times <1 ms) of the reduction of dichlorophenolindophenol by L-ascorbic acid suggest that TM (1) -DESI can access reaction times less than 1 ms. Multiple meshes allow sequential stages of desorption/ionization per MS scan, increasing the number of analytes and reactions that can be characterized in a single experiment.
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Affiliation(s)
- Kevin C Peters
- Department of Chemistry, University of Illinois, Urbana, IL, 61801, USA
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14
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Karamzadeh B, Singh D, Nam W, Kumar D, de Visser SP. Properties and reactivities of nonheme iron(IV)-oxo versus iron(V)-oxo: long-range electron transfer versus hydrogen atom abstraction. Phys Chem Chem Phys 2015; 16:22611-22. [PMID: 25231726 DOI: 10.1039/c4cp03053b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Recent work of Nam and co-workers [J. Yoon, S. A. Wilson, Y. K. Jang, M. S. Seo, K. Nehru, B. Hedman, K. O. Hodgson, E. Bill, E. I. Solomon and W. Nam, Angew. Chem., Int. Ed., 2009, 48, 1257] on a biomimetic iron complex implicated a mixture of iron(IV)-oxo and iron(V)-oxo intermediates but the latter could not be spectroscopically characterized, hence its involvement was postulated. To gain insight into the relative activity of these iron(IV)-oxo versus iron(V)-oxo intermediates, we have performed an extensive density functional theory (DFT) study on the chemical properties of the chemical system of Nam et al., namely [Fe(O)(BQEN)(NCCH3)](2+/3+) with BQEN = N,N'-dimethyl-N,N'-bis(8-quinolyl)ethane-1,2-diamine and their reactivity in hydrogen atom abstraction from ethylbenzene. We show that the perceived iron(V)-oxo species actually is an iron(IV)-oxo ligand cation radical, similar to cytochrome P450 compound I. Moreover, this intermediate has an extremely large electron affinity and therefore can abstract electrons from substrates readily. In our particular system, this means that prior to the hydrogen atom abstraction, an electron is abstracted to form an iron(IV)-oxo species, which subsequently abstracts a hydrogen atom from the substrate. Thus, our calculations show for the first time how some nonheme iron complexes react by long-range electron transfer and others directly via hydrogen atom abstraction. We have rationalized our results with detailed thermochemical cycles that explain the observed reactivity patterns.
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Affiliation(s)
- Baharan Karamzadeh
- Manchester Institute of Biotechnology and School of Chemical Engineering and Analytical Science, the University of Manchester, 131 Princess Street, Manchester M1 7DN, UK.
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15
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Warner GR, Mills MR, Enslin C, Pattanayak S, Panda C, Panda TK, Gupta SS, Ryabov AD, Collins TJ. Reactivity and Operational Stability ofN-Tailed TAMLs through Kinetic Studies of the Catalyzed Oxidation of Orange II by H2O2: Synthesis and X-ray Structure of anN-Phenyl TAML. Chemistry 2015; 21:6226-33. [DOI: 10.1002/chem.201406061] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Indexed: 11/08/2022]
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16
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Demiyanova AS, Sakharov IY. High chemiluminescence activity of an FeIII–TAML activator in aqueous–organic media and its use in the determination of organic peroxides. Analyst 2015; 140:2964-8. [DOI: 10.1039/c4an01943a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Using FeIII–TAML, highly active peroxidase mimic, the sensitive chemiluminescence assays for the determination of benzoyl peroxide and tert-butyl hydroperoxide in the presence of organic solvents were developed.
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Affiliation(s)
| | - Ivan Yu. Sakharov
- Department of Chemistry
- Lomonosov Moscow State University
- Moscow 119991
- Russia
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17
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Kundu S, Thompson JVK, Shen LQ, Mills MR, Bominaar EL, Ryabov AD, Collins TJ. Activation parameters as mechanistic probes in the TAML iron(V)-oxo oxidations of hydrocarbons. Chemistry 2014; 21:1803-10. [PMID: 25410933 DOI: 10.1002/chem.201405024] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Indexed: 11/11/2022]
Abstract
The results of low-temperature investigations of the oxidations of 9,10-dihydroanthracene, cumene, ethylbenzene, [D10]ethylbenzene, cyclooctane, and cyclohexane by an iron(V)-oxo TAML complex (2; see Figure 1) are presented, including product identification and determination of the second-order rate constants k2 in the range 233-243 K and the activation parameters (ΔH(≠) and ΔS(≠)). Statistically normalized k2 values (log k2') correlate linearly with the C-H bond dissociation energies DC-H, but ΔH(≠) does not. The point for 9,10-dihydroanthracene for the ΔH(≠) vs. DC-H correlation lies markedly off a common straight line of best fit for all other hydrocarbons, suggesting it proceeds via an alternate mechanism than the rate-limiting C-H bond homolysis promoted by 2. Contribution from an electron-transfer pathway may be substantial for 9,10-dihydroanthracene. Low-temperature kinetic measurements with ethylbenzene and [D10]ethylbenzene reveal a kinetic isotope effect of 26, indicating tunneling. The tunnel effect is drastically reduced at 0 °C and above, although it is an important feature of the reactivity of TAML activators at lower temperatures. The diiron(IV) μ-oxo dimer that is often a common component of the reaction medium involving 2 also oxidizes 9,10-dihydroanthracene, although its reactivity is three orders of magnitude lower than that of 2.
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Affiliation(s)
- Soumen Kundu
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA, 15213 (USA)
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18
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Vdovenko MM, Demiyanova AS, Kopylov KE, Sakharov IY. FeIII–TAML activator: A potent peroxidase mimic for chemiluminescent determination of hydrogen peroxide. Talanta 2014; 125:361-5. [DOI: 10.1016/j.talanta.2014.03.040] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 03/11/2014] [Accepted: 03/17/2014] [Indexed: 10/25/2022]
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