1
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Palit D, Kundu S, Pain PK, Sarma R, Manna D. A Chemical Model of a TET Enzyme for Selective Oxidation of Hydroxymethyl Cytosine to Formyl Cytosine. Inorg Chem 2023. [PMID: 37339080 DOI: 10.1021/acs.inorgchem.3c00063] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2023]
Abstract
Methylation/demethylation of cytosines in DNA is central to epigenetics, which plays crucial roles in the regulation of about half of all human genes. Although the methylation mechanism, which downregulates gene expression, has been sufficiently decoded; the demethylation pathway, which upregulates gene expression, still holds questions to be answered. Demethylation of 5-methylcytosine by ten-eleven translocation (TET) enzymes yields understudied but epigenetically relevant intermediates, 5-hydroxymethyl (5-hmC), 5-formyl (5-fC), and 5-carboxyl (5-caC) cytosines. Here we report an iron complex, FeIIITAML (TAML = tetraamido macrocyclic ligand), which can facilitate selective oxidation of 5-hmC to its oxidative derivatives by forming a high-valent Fe-oxo intermediate in the presence of H2O2 under physiologically relevant conditions. Detailed HPLC analyses supported by a wide reaction condition optimization for the 5-hmC → 5-fC oxidation provides us with a chemical model of the TET enzyme. This study shines light on future efforts for a better understanding of the roles of 5-hmC and the TET enzyme mechanism and potentially novel therapeutic methods.
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Affiliation(s)
- Dipanwita Palit
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal, MP 462066, India
| | - Shubhankar Kundu
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal, MP 462066, India
| | - Pritam Kumar Pain
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal, MP 462066, India
| | - Rajdeep Sarma
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal, MP 462066, India
| | - Debasish Manna
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal, MP 462066, India
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2
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Xie J, Xie J, Miller CJ, Waite TD. Enhanced Direct Electron Transfer Mediated Contaminant Degradation by Fe(IV) Using a Carbon Black-Supported Fe(III)-TAML Suspension Electrode System. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:2557-2565. [PMID: 36725204 DOI: 10.1021/acs.est.2c08467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Iron complexes of tetra-amido macrocyclic ligands (Fe-TAML) are recognized to be effective catalysts for the degradation of a wide range of organic contaminants in homogeneous conditions with the high valent Fe(IV) and Fe(V) species generated on activation of the Fe-TAML complex by hydrogen peroxide (H2O2) recognized to be powerful oxidants. Electrochemical activation of Fe-TAML would appear an attractive alternative to H2O2 activation, especially if the Fe-TAML complex could be attached to the anode, as this would enable formation of high valent iron species at the anode and, importantly, retention of the valuable Fe-TAML complex within the reaction system. In this work, we affix Fe-TAML to the surface of carbon black particles and apply this "suspension anode" process to oxidize selected target compounds via generation of high valent iron species. We show that the overpotential for Fe(IV) formation is 0.17 V lower than the potential required to generate Fe(IV) electrochemically in homogeneous solution and also show that the stability of the Fe(IV) species is enhanced considerably compared to the homogeneous Fe-TAML case. Application of the carbon black-supported Fe-TAML suspension anode reactor to degradation of oxalate and hydroquinone with an initial pH value of 3 resulted in oxidation rate constants that were up to three times higher than could be achieved by anodic oxidation in the absence of Fe-TAML and at energy consumptions per order of removal substantially lower than could be achieved by alternate technologies.
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Affiliation(s)
- Jiangzhou Xie
- UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW2052, Australia
- UNSW Centre for Transformational Environmental Technologies, Yixing, Jiangsu Province, 214206, P.R. China
| | - Jieli Xie
- UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW2052, Australia
| | - Christopher J Miller
- UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW2052, Australia
| | - T David Waite
- UNSW Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW2052, Australia
- UNSW Centre for Transformational Environmental Technologies, Yixing, Jiangsu Province, 214206, P.R. China
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3
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Frame HC, Shen LQ, Ryabov AD, Collins TJ. On TAML Catalyst Resting State Lifetimes: Kinetic, Mechanistic, and Theoretical Insight into Phosphate-Induced Demetalation of an Iron(III) Bis(sulfonamido)bis(amido)-TAML Catalyst. Inorg Chem 2023; 62:639-647. [PMID: 36599101 DOI: 10.1021/acs.inorgchem.2c03854] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
At ambient temperatures, neutral pH and ultralow concentrations (low nM), the bis(sulfonamido)bis(amido) oxidation catalyst [Fe{4-NO2C6H3-1,2-(NCOCMe2NSO2)2CHMe}(OH2)]- (1) has been shown to catalyze the addition of an oxygen atom to microcystin-LR. This persistent bacterial toxin can contaminate surface waters and render drinking water sources unusable when nutrient concentrations favor cyanobacterial blooms. In mechanistic studies of this oxidation, while the pH was controlled with phosphate buffers, it became apparent that iron ejection from 1 becomes increasingly problematic with increasing [phosphate] (0.3-1.0 M); 1 is not noticeably impacted at low concentrations (0.01 M). At pH < 6.5 and [phosphate] ≥ 1.0 M, 1 decays quickly, losing iron from the macrocycle. Iron ejection is surprisingly mechanistically complex; the pseudo-first-order rate constant kobs has an unusual dependence on the total phosphate concentration ([Pt]), kobs = k1[Pt] + k2[Pt]2, indicating two parallel pathways that are first and second order in [phosphate], respectively. The pH profiles in the 5.5-8.3 range for k1 and k2 are different: bell-shaped with a maximum of around pH 7 for k1 and sigmoidal for k2 with higher values at lower pH. Mechanistic proposals for the k1 and k2 pathways are detailed based on both the kinetic data and density functional theory analysis. The major difference between k1 and k2 is the involvement of different phosphate species, i.e., HPO42- (k1) and H2PO4- (k2); HPO42- is less acidic but more nucleophilic, which favors intramolecular rate-limiting Fe-N bond cleavage. Instead, H2PO4- acts intermolecularly, where the kinetics suggest that [H4P2O8]2- drives degradation.
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Affiliation(s)
- Hannah C Frame
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania15213, United States
| | - Longzhu Q Shen
- Faculty of Geoinformation Science and Earth Observation, University of Twente, Hengelosestraat 99, Enschede, 7514AE, The Netherlands
| | - Alexander D Ryabov
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania15213, United States
| | - Terrence J Collins
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania15213, United States
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4
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Zhou A, Fu Z, Cao X, Zhao Y, Wang Y. A mechanistic switch in C−H bond activation by elusive Fe V(O)(TAML) reaction intermediate: A theoretical study. CHINESE J CHEM PHYS 2022. [DOI: 10.1063/1674-0068/cjcp2111230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The divergent behavior of C−H bond oxidations of aliphatic substrates compared to those of aromatic substrates shown in Gupta's experiment was mechanistically studied herein by means of density functional theory calculations. Our calculations reveal that such difference is caused by different reaction mechanisms between two kinds of substrates (the aliphatic cyclohexane, 2,3-dimethylbutane and the aromatic toluene, ethylbenzene and cumene). For the aliphatic substrates, C−H oxidation by the oxidant FeV(O)(TAML) is a hydrogen atom transfer process; whereas for the aromatic substrates, C−H oxidation is a proton-coupled electron transfer (PCET) process with a proton transfer character on the transition state, that is, a proton-coupled electron transfer process holding a proton transfer-like transition state (PCET(PT)). This difference is caused by the strong π− π interactions between the tetra-anionic TAML ring and the phenyl ring of the aromatic substrates, which has a “pull” effect to make the electron transfer from substrates to the Fe=O moiety inefficient.
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Affiliation(s)
- Anran Zhou
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, China
- Qian Xuesen Collaborative Research Center of Astrochemistry and Space Life Sciences, Ningbo University, Ningbo 315211, China
| | - Zhiqiang Fu
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
| | - Xuanyu Cao
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, China
- Qian Xuesen Collaborative Research Center of Astrochemistry and Space Life Sciences, Ningbo University, Ningbo 315211, China
| | - Yufen Zhao
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, China
- Qian Xuesen Collaborative Research Center of Astrochemistry and Space Life Sciences, Ningbo University, Ningbo 315211, China
| | - Yong Wang
- Institute of Drug Discovery Technology, Ningbo University, Ningbo 315211, China
- Qian Xuesen Collaborative Research Center of Astrochemistry and Space Life Sciences, Ningbo University, Ningbo 315211, China
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5
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Ren C, Liu J. Bioinspired Catalytic Reduction of Aqueous Perchlorate by One Single-Metal Site with High Stability against Oxidative Deactivation. ACS Catal 2021. [DOI: 10.1021/acscatal.0c05276] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Changxu Ren
- Department of Chemical and Environmental Engineering, University of California, Riverside, California 92521, United States
| | - Jinyong Liu
- Department of Chemical and Environmental Engineering, University of California, Riverside, California 92521, United States
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6
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Jin Q, Chen Z, Chen Q, Yan P, Zhao S, Shen J, Li L, Guo F, Kang J. Structure activity relationship study of N-doped ligand modified Fe(III)/H 2O 2 for degrading organic pollutants. JOURNAL OF HAZARDOUS MATERIALS 2021; 404:124142. [PMID: 33059248 DOI: 10.1016/j.jhazmat.2020.124142] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 09/24/2020] [Accepted: 09/28/2020] [Indexed: 06/11/2023]
Abstract
The performance of Fe(III)/H2O2 was extremely enhanced by a novel N-doped ligand dipicolinamide (Dpa) for removing various organic pollutants. This dramatic enhancement of contaminants degradation in Fe(III)-Dpa/H2O2 system under pH≥ 7 was ascribed to the coordinating capacity of Dpa to form the dissolved Fe(III)-Dpa/Fe(II)-Dpa, and the reductive capacity of Dpa to maintain the concentration of Fe(II), which made Dpa improve the catalytic performance of Fe(III) nearly twice as much as Fe(II). Dpa has a strong complexing ability than Cit, NTA, and EDTA to maintain the catalytic activity of Fe(III) without light. The single crystal of Fe-Dpa was obtained to reveal its structure activity relationship. Fe-Dpa was composed of four bonds of Fe-N and two bonds of Fe-Cl. The Fe-Cl bonds were labile sites, which was easily experienced ligand exchange with H2O2, resulting Fe-H2O2 bonds to initiate degradation reaction. The remaining Fe-N bonds were effectively planar, which had a large delocalized π electrons flow domain, enhancing the production of multiple reactive species, including iron(IV/V)-oxo species, HO· and O2-·. An empirical kinetic model of Fe(III)-Dpa/H2O2 system was established. In addition, the evaluation results of the toxicity of Fe-Dpa to larval zebrafish and chinese cabbage displayed that Fe-Dpa possesses low toxicity.
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Affiliation(s)
- Qianqian Jin
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Zhonglin Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Qian Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China; Key Laboratory of State Forestry and Grassland Administration on Highly-Efficient Utilization of Forestry Biomass Resources in Southwest China, School of Chemical Engineering, Southwest Forestry University, Kunming 650224, China.
| | - Pengwei Yan
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Shengxin Zhao
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Jimin Shen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Li Li
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150080, China
| | - Fang Guo
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150080, China
| | - Jing Kang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
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7
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McNeice P, Reid A, Imam HT, McDonagh C, Walby JD, Collins TJ, Marr AC, Marr PC. Designing Materials for Aqueous Catalysis: Ionic Liquid Gel and Silica Sphere Entrapped Iron-TAML Catalysts for Oxidative Degradation of Dyes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:14026-14035. [PMID: 33103422 DOI: 10.1021/acs.est.0c04279] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Materials have been developed that encapsulate a homogeneous catalyst and enable it to operate as a heterogeneous catalyst in water. A hydrophobic ionic liquid within the material was used to dissolve Fe-TAML and keep it from leaching into the aqueous phase. One-pot processes were used to entrap Fe-TAML in basic ionic liquid gels, and ionic liquid gel spheres structured via a modified Stöber synthesis forming SiO2 particles of uniform size. Catalytic activity was demonstrated via the oxidative degradation of dyes. Fe-TAML entrapped in a basic ionic liquid gel exhibited consistent activity in five recycles. This discovery of heterogenized H2O2 activators prepared by sol-gel and Stöber processes opens new possibilities for the creation of engineered catalytic materials for water purification.
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Affiliation(s)
- Peter McNeice
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
- Queen's University Ionic Liquids Laboratories, David Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
| | - Andrew Reid
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
| | - Hasan T Imam
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
- Queen's University Ionic Liquids Laboratories, David Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
| | - Carol McDonagh
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
| | - Joel D Walby
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
| | - Terrence J Collins
- Institute for Green Science, Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Andrew C Marr
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
- Queen's University Ionic Liquids Laboratories, David Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
| | - Patricia C Marr
- School of Chemistry and Chemical Engineering, Queen's University Belfast, David Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
- Queen's University Ionic Liquids Laboratories, David Keir Building, Stranmillis Road, Belfast BT9 5AG, United Kingdom
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8
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Wang C, Xian Z, Ding Y, Jin X, Gu C. Self-assembly of Fe III-TAML-based microstructures for rapid degradation of bisphenols. CHEMOSPHERE 2020; 256:127104. [PMID: 32470734 DOI: 10.1016/j.chemosphere.2020.127104] [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: 01/13/2020] [Revised: 05/14/2020] [Accepted: 05/15/2020] [Indexed: 06/11/2023]
Abstract
Iron(III)-tetraamidomacrocyclic ligand (FeIII-TAML) activators have drawn great attentions due to the high reactivity to degrade organic pollutants. However, previous studies showed that the reactivity and stability of FeIII-TAML were both strongly pH-dependent, which dramatically decrease at lower pH levels. Herein, FeIII-TAML/DODMA (dimethyldioctadecylammonium chloride) microspheres with diameters ranging from 100 to 2000 nm were synthesized via a surfactant-assisted self-assembly technique. The newly synthesized FeIII-TAML/DODMA composite exhibits superior reactivity compared to free FeIII-TAML as indicated by the degradation of bisphenols (i.e., bisphenol A and its analogues) over a wide pH range (i.e., pH 4.5-10.0). Based on the adsorption results and quantitative structure-activity relationship (QSAR) models, the enhanced reactivity of FeIII-TAML/DODMA is mainly ascribed to the hydrophobic sorption of bisphenols. Moreover, the enhanced ionization of the axial water molecule associated with FeIII-TAML could further enhance the reactivity of synthesized microcomposites, which was confirmed by the results of infrared and Raman spectra. Furthermore, FeIII-TAML/DODMA shows distinct acid-resistance as explained by the protection of the hydrophobic alkyl chains of DODMA. This novel method would provide a simple and effective strategy to expand the application of FeIII-TAML in a wide pH range and render FeIII-TAML/DODMA microstructure as a potential catalyst for treatment of bisphenol compounds.
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Affiliation(s)
- Chao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - Zeyu Xian
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - Yunhao Ding
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China
| | - Xin Jin
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China; Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, PR China
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China.
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9
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Kundu S, Shen LQ, Somasundar Y, Annavajhala M, Ryabov AD, Collins TJ. TAML- and Buffer-Catalyzed Oxidation of Picric Acid by H 2O 2: Products, Kinetics, DFT, and the Mechanism of Dual Catalysis. Inorg Chem 2020; 59:13223-13232. [DOI: 10.1021/acs.inorgchem.0c01581] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Soumen Kundu
- Institute for Green Science, 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, United Kingdom
| | - Yogesh Somasundar
- Institute for Green Science, Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Medini Annavajhala
- Institute for Green Science, Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Alexander D. Ryabov
- Institute for Green Science, Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Terrence J. Collins
- Institute for Green Science, Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
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10
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Farinelli G, Minella M, Sordello F, Vione D, Tiraferri A. Metabisulfite as an Unconventional Reagent for Green Oxidation of Emerging Contaminants Using an Iron-Based Catalyst. ACS OMEGA 2019; 4:20732-20741. [PMID: 31858059 PMCID: PMC6906940 DOI: 10.1021/acsomega.9b03088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 11/13/2019] [Indexed: 06/10/2023]
Abstract
In this work, contaminants of emerging concern were catalytically degraded in the homogeneous phase with the use of unconventional green reagents. Three reagents, namely, sulfite, metabisulfite, and persulfate, were tested and compared with conventional hydrogen peroxide in the degradation process activated by Fe-TAML. The latter is a biodegradable, homogeneous tetra-amido macrocyclic ligand catalyst containing iron(III). Metabisulfite showed the highest efficiency among the three tested reagents, and its reactivity was similar to that of H2O2. However, metabisulfite is a safer and cleaner reagent compared to H2O2. A comprehensive study of the activity of metabisulfite with Fe-TAML was carried out toward the oxidative degradation of eight contaminants of emerging concern. The catalytic process was tested at different pH values (7, 9, and 11). Metabisulfite showed the highest activity at pH 11, completely degrading some of the tested micropollutants, but in several cases, the system was active at pH 9 as well. In particular, metabisulfite showed the best efficiency toward phenolic compounds. A preliminary study on the reaction mechanism and the nature of the active species in the Fe-TAML/metabisulfite system was also conducted, highlighting that a high-valent iron-oxo species might be involved in the degradation pathways.
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Affiliation(s)
- Giulio Farinelli
- Department
of Environment, Land and Infrastructure Engineering (DIATI), Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
| | - Marco Minella
- Department
of Chemistry, University of Turin, Via Pietro Giuria 5, 10125 Turin, Italy
| | - Fabrizio Sordello
- Department
of Chemistry, University of Turin, Via Pietro Giuria 5, 10125 Turin, Italy
| | - Davide Vione
- Department
of Chemistry, University of Turin, Via Pietro Giuria 5, 10125 Turin, Italy
| | - Alberto Tiraferri
- Department
of Environment, Land and Infrastructure Engineering (DIATI), Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy
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11
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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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12
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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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13
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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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14
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Wang C, Gao J, Gu C. Rapid Destruction of Tetrabromobisphenol A by Iron(III)-Tetraamidomacrocyclic Ligand/Layered Double Hydroxide Composite/H 2O 2 System. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:488-496. [PMID: 27977161 DOI: 10.1021/acs.est.6b04294] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Iron(III)-tetraamidomacrocyclic ligand (Fe(III)-TAML) activators have received widespread attentions for their abilities to activate hydrogen peroxide to oxidize many organic pollutants. In this study, Fe(III)-TAML/layered double hydroxide (LDH) composite was developed by intercalating Fe(III)-TAML into the interlayer of LDH. Electrostatic interaction and hydrogen bonding might account for the adsorption of Fe(III)-TAML on LDH. The newly synthesized Fe(III)-TAML/LDH composite showed superior reactivity as indicated by efficient decomposition of tetrabromobisphenol A (TBBPA) in the presence of hydrogen peroxide, which can be fully degraded within 20 s and the degradation rate increased up to 8 times compared to free Fe(III)-TAML. In addition, the toxicity of the system was significantly reduced after the reaction. The higher reactivity of Fe(III)-TAML/LDH system is attributed to the enhanced adsorption of TBBPA on LDH, which could increase the contact possibility between Fe(III)-TAML and TBBPA. On the basis of the analysis of reaction intermediates, β-scission at the middle carbon atom and C-Br bond cleavage in phenyl ring of TBBPA were involved in the degradation process. Furthermore, our results demonstrated that the Fe(III)-TAML/LDH composite can be reused several times, which could lower the overall cost for environmental implication and render Fe(III)-TAML/LDH as the potential environmentally friendly catalyst for future wastewater treatment under mild reaction conditions.
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Affiliation(s)
- Chao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing 210023, P.R. China
| | - Juan Gao
- Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences , Nanjing, Jiangsu 210008, P. R. China
| | - Cheng Gu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University , Nanjing 210023, P.R. China
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15
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Li J, Güttinger R, Moré R, Song F, Wan W, Patzke GR. Frontiers of water oxidation: the quest for true catalysts. Chem Soc Rev 2017; 46:6124-6147. [DOI: 10.1039/c7cs00306d] [Citation(s) in RCA: 178] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Development of advanced analytical techniques is essential for the identification of water oxidation catalysts together with mechanistic studies.
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Affiliation(s)
- J. Li
- University of Zurich
- Department of Chemistry
- CH-8057 Zurich
- Switzerland
| | - R. Güttinger
- University of Zurich
- Department of Chemistry
- CH-8057 Zurich
- Switzerland
| | - R. Moré
- University of Zurich
- Department of Chemistry
- CH-8057 Zurich
- Switzerland
| | - F. Song
- University of Zurich
- Department of Chemistry
- CH-8057 Zurich
- Switzerland
| | - W. Wan
- University of Zurich
- Department of Chemistry
- CH-8057 Zurich
- Switzerland
| | - G. R. Patzke
- University of Zurich
- Department of Chemistry
- CH-8057 Zurich
- Switzerland
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16
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Mills MR, Burton AE, Mori DI, Ryabov AD, Collins TJ. Iron(IV) or iron(V)? Heterolytic or free radical? Oxidation pathways of a TAML activator in acetonitrile at −40 °C. J COORD CHEM 2015. [DOI: 10.1080/00958972.2015.1073270] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Matthew R. Mills
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Abigail E. Burton
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Dylan I. Mori
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA, USA
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17
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Crabtree RH. Deactivation in Homogeneous Transition Metal Catalysis: Causes, Avoidance, and Cure. Chem Rev 2014; 115:127-50. [DOI: 10.1021/cr5004375] [Citation(s) in RCA: 251] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Robert H. Crabtree
- Department
of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, United States
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18
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Panda C, Debgupta J, Díaz Díaz D, Singh KK, Sen Gupta S, Dhar BB. Homogeneous photochemical water oxidation by biuret-modified Fe-TAML: evidence of Fe(V)(O) intermediate. J Am Chem Soc 2014; 136:12273-82. [PMID: 25119524 DOI: 10.1021/ja503753k] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Water splitting, leading to hydrogen and oxygen in a process that mimics natural photosynthesis, is extremely important for devising a sustainable solar energy conversion system. Development of earth-abundant, transition metal-based catalysts that mimic the oxygen-evolving complex of photosystem II, which is involved in oxidation of water to O2 during natural photosynthesis, represents a major challenge. Further, understanding the exact mechanism, including elucidation of the role of active metal-oxo intermediates during water oxidation (WO), is critical to the development of more efficient catalysts. Herein, we report Fe(III) complexes of biuret-modified tetra-amidomacrocyclic ligands (Fe-TAML; 1a and 1b) that catalyze fast, homogeneous, photochemical WO to give O2, with moderate efficiency (maximum TON = 220, TOF = 0.76 s(-1)). Previous studies on photochemical WO using iron complexes resulted in demetalation of the iron complexes with concomitant formation of iron oxide nanoparticles (NPs) that were responsible for WO. Herein, we show for the first time that a high valent Fe(V)(O) intermediate species is photochemically generated as the active intermediate for the oxidation of water to O2. To the best of our knowledge, this represents the first example of a molecular iron complex catalyzing photochemical WO through a Fe(V)(O) intermediate.
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Affiliation(s)
- Chakadola Panda
- Chemical Engineering and Process Development Division, CSIR-National Chemical Laboratory , Dr. Homi Bhabha Road, Pune 411008, India
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19
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McGrail BT, Pianowski LS, Burns PC. Photochemical Water Oxidation and Origin of Nonaqueous Uranyl Peroxide Complexes. J Am Chem Soc 2014; 136:4797-800. [DOI: 10.1021/ja502425t] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Brendan T. McGrail
- Department of Civil & Environmental Engineering & Earth Sciences and ‡Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Laura S. Pianowski
- Department of Civil & Environmental Engineering & Earth Sciences and ‡Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Peter C. Burns
- Department of Civil & Environmental Engineering & Earth Sciences and ‡Department of Chemistry & Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
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20
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Napoly F, Jean-Gérard L, Goux-Henry C, Draye M, Andrioletti B. Fe(TAML)Li/(diacetoxyiodo)benzene-Mediated Oxidation of Alcohols: Evidence for Mild and Selective C-O and C-C Oxidative Cleavage in Lignin Model Transformations. European J Org Chem 2013. [DOI: 10.1002/ejoc.201301093] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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21
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Truong L, DeNardo MA, Kundu S, Collins TJ, Tanguay RL. Zebrafish Assays as Developmental Toxicity Indicators in The Design of TAML Oxidation Catalysts. GREEN CHEMISTRY : AN INTERNATIONAL JOURNAL AND GREEN CHEMISTRY RESOURCE : GC 2013; 15:2339-2343. [PMID: 24748850 PMCID: PMC3989102 DOI: 10.1039/c3gc40376a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
TAML activators promise a novel water treatment approach by efficiently catalysing peroxide-based degradation of chemicals of high concern at environmental concentrations. Green design ethics demands an exploration of TAML toxicity. Exposure to high concentrations of certain activators caused adverse effects in zebrafish. At typical TAML operational concentrations, development was not perturbed.
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Affiliation(s)
- Lisa Truong
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, 28645 East HWY 34, Corvallis, OR 97333, USA. Fax: 01 541 737 6074; Tel: 01 541 737 6514
| | - Matthew A. DeNardo
- Institute for Green Science, Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, USA. Fax: 01 412 268 1061; Tel: 01 412 268 6335
| | - Soumen Kundu
- Institute for Green Science, Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, USA. Fax: 01 412 268 1061; Tel: 01 412 268 6335
| | - Terrence J. Collins
- Institute for Green Science, Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, USA. Fax: 01 412 268 1061; Tel: 01 412 268 6335
| | - Robert L. Tanguay
- Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Environmental Health Sciences Center, Oregon State University, 28645 East HWY 34, Corvallis, OR 97333, USA. Fax: 01 541 737 6074; Tel: 01 541 737 6514
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23
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Ma J, Ma W, Chen C, Ji H, Zhao J. An Efficient Anthraquinone-Resin Hybrid Co-Catalyst for Fenton-Like Reactions: Acceleration of the Iron Cycle Using a Quinone Cycle under Visible-Light Irradiation. Chem Asian J 2011; 6:2264-8. [DOI: 10.1002/asia.201100347] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Indexed: 11/08/2022]
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Panda C, Ghosh M, Panda T, Banerjee R, Sen Gupta S. Fe(III) complex of biuret-amide based macrocyclic ligand as peroxidase enzyme mimic. Chem Commun (Camb) 2011; 47:8016-8. [PMID: 21674085 DOI: 10.1039/c1cc12686e] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An Fe(III) complex of a biuret-amide based macrocyclic ligand that exhibits both excellent reactivity for the activation of H(2)O(2) and high stability, especially at low pH and high ionic strength, is reported.
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Affiliation(s)
- Chakadola Panda
- CReST.Chemical Engineering Div., National Chemical laboratory, Dr Homi Bhabha Road, Pune, India 411008
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25
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Mierzwicki K, Berski S, Latajka Z. AIM and ELF analysis of the H-, Me-, and F-substituted FeIII–TAML complexes. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2011.03.044] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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26
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Popescu DL, Vrabel M, Brausam A, Madsen P, Lente G, Fabian I, Ryabov AD, van Eldik R, Collins TJ. Thermodynamic, electrochemical, high-pressure kinetic, and mechanistic studies of the formation of oxo Fe(IV)-TAML species in water. Inorg Chem 2010; 49:11439-48. [PMID: 21086984 DOI: 10.1021/ic1015109] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Stopped-flow kinetic studies of the oxidation of Fe(III)-TAML catalysts, [ F e{1,2-X(2)C(6)H(2)-4,5-( NCOCMe(2) NCO)(2)CMe(2)}(OH(2))](-) (1), by t-BuOOH and H(2)O(2) in water affording Fe(IV) species has helped to clarify the mechanism of the interaction of 1 with primary oxidants. The data collected for substituted Fe(III)-TAMLs at pH 6.0-13.8 and 17-45 °C has confirmed that the reaction is first order both in 1 and in peroxides. Bell-shaped pH profiles of the effective second-order rate constants k(I) have maximum values in the pH range of 10.5-12.5 depending on the nature of 1 and the selected peroxide. The "acidic" part is governed by the deprotonation of the diaqua form of 1 and therefore electron-withdrawing groups move the lower pH limit of the reactivity toward neutral pH, although the rate constants k(I) do not change much. The dissection of k(I) into individual intrinsic rate constants k(1) ([FeL(OH(2))(2)](-) + ROOH), k(2) ([FeL(OH(2))OH)](2-) + ROOH), k(3) ([FeL(OH(2))(2)](-) + ROO(-)), and k(4) ([FeL(OH(2))OH)](2-) + ROO(-)) provides a model for understanding the bell-shaped pH-profiles. Analysis of the pressure and substituent effects on the reaction kinetics suggest that the k(2) pathway is (i) more probable than the kinetically indistinguishable k(3) pathway, and (ii) presumably mechanistically similar to the induced cleavage of the peroxide O-O bond postulated for cytochrome P450 enzymes. The redox titration of 1 by Ir(IV) and electrochemical data suggest that under basic conditions the reduction potential for the half-reaction [Fe(IV)L(=O)(OH(2))](2-) + e(-) + H(2)O → [Fe(III)L(OH)(OH(2))](2-) + OH(-) is close to 0.87 V (vs NHE).
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Affiliation(s)
- Delia-Laura Popescu
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
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Ellis WC, Tran CT, Roy R, Rusten M, Fischer A, Ryabov AD, Blumberg B, Collins TJ. Designing green oxidation catalysts for purifying environmental waters. J Am Chem Soc 2010; 132:9774-81. [PMID: 20565079 DOI: 10.1021/ja102524v] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We describe the synthesis, characterization, aqueous behavior, and catalytic activity of a new generation of Fe(III)-TAML (tetraamido macrocycle ligand) activators of peroxides (2), variants of [Fe{(OC)(2)(o,o'-NC(6)H(4)NCO)(2)CMe(2)}(OH(2))(-)] (2d), which have been designed to be especially suitable for purifying water of recalcitrant oxidizable pollutants. Activation of H(2)O(2) by 2 (k(I)) as a function of pH was analyzed via kinetic studies of Orange II bleaching. This was compared with the known behavior of the first generation of Fe(III)-TAMLs (1). Novel reactivity features impact the potential for oxidant activation for water purification by 2d and its aromatic ring-substituted dinitro (2e) and tetrachloro (2f) derivatives. Thus, the maximum activity for 2e occurs at pH 9, the closest yet to the EPA guidelines for drinking water (6.5-8.5), allowing 2e to rapidly activate H(2)O(2) at pH 7.7. In water, 2e has two axial water ligands with pK(a)'s of 8.4 and 10.0 (25 degrees C). The former is the lowest for all Fe(III)-TAMLs developed to date and is key to 2e's exceptional catalytic activity in neutral and slightly basic solutions. Below pH 7, 2d was found to be quite sensitive to demetalation in phosphate buffers. This was overcome by iterative design to give 2e (hydrolysis rate 2d > 100 x 2e). Mechanistic studies highlight 2e's increased stability by establishing that to demetalate 2e at a comparable rate to which H(2)PO(4)(-) demetalates 2d, H(3)PO(4) is required. A critical criterion for green catalysts for water purification is the avoidance of endocrine disruptors, which can impair aquatic life. Fe(III)-TAMLs do not alter transcription mediated by mammalian thyroid, androgen, or estrogen hormone receptors, suggesting that 2 do not bind to the receptors and reducing concerns that the catalysts might have endocrine disrupting activity.
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Affiliation(s)
- W Chadwick Ellis
- Department of Chemistry, Institute of Green Science, Mellon Institute, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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28
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Mitchell DA, Ryabov AD, Kundu S, Chanda A, Collins TJ. Oxidation of pinacyanol chloride by H2O2 catalyzed by FeIII complexed to tetraamidomacrocyclic ligand: unusual kinetics and product identification. J COORD CHEM 2010. [DOI: 10.1080/00958972.2010.492426] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Douglas A. Mitchell
- a Department of Chemistry , Carnegie Mellon University , 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
- b Department of Chemistry and the Institute for Genomic Biology , University of Illinois at Urbana-Champaign , 1206 W. Gregory Dr, Urbana, IL 61801, USA
| | - Alexander D. Ryabov
- a Department of Chemistry , Carnegie Mellon University , 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
| | - Soumen Kundu
- a Department of Chemistry , Carnegie Mellon University , 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
| | - Arani Chanda
- a Department of Chemistry , Carnegie Mellon University , 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
- c Eisai Inc. , 100 Federal St, Andover, MA 01810, USA
| | - Terrence J. Collins
- a Department of Chemistry , Carnegie Mellon University , 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
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Ellis WC, Tran CT, Denardo MA, Fischer A, Ryabov AD, Collins TJ. Design of more powerful iron-TAML peroxidase enzyme mimics. J Am Chem Soc 2010; 131:18052-3. [PMID: 19928965 DOI: 10.1021/ja9086837] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Environmentally useful, small molecule mimics of the peroxidase enzymes must exhibit very high reactivity in water near neutral pH. Here we describe the design and structural and kinetic characterization of a second generation of iron(III)-TAML activators with unprecedented peroxidase-mimicking abilities. Iterative design has been used to remove the fluorine that led to the best performers in first-generation iron-TAMLs. The result is a superior catalyst that meets a green chemistry objective by being comprised exclusively of biochemically common elements. The rate constants for bleaching at pH 7, 9, and 11 of the model substrate, Orange II, shows that the new Fe(III)-TAML has the fastest reactivity at pH's closer to neutral of any TAML activator to date. Under appropriate conditions, the new catalyst can decolorize Orange II without loss of activity for at least 10 half-lives, attesting to its exceptional properties as an oxidizing enzyme mimic.
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Affiliation(s)
- W Chadwick Ellis
- Institute for Green Science, Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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Banerjee D, Apollo FM, Ryabov AD, Collins TJ. The impact of surfactants on Fe(III)-TAML-catalyzed oxidations by peroxides: accelerations, decelerations, and loss of activity. Chemistry 2010; 15:10199-209. [PMID: 19711381 DOI: 10.1002/chem.200900729] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Iron(III) complexes of tetraamidato macrocyclic ligands (TAMLs), [Fe{4-XC(6)H(3)-1,2-(NCOCMe(2)NCO)(2)CR(2)}(OH(2))](-), 1 (1 a: X = H, R = Me; 1 b: X = COOH, R = Me); 1 c: X = CONH(CH(2))(2)COOH, R = Me; 1 d: CONH(CH(2))(2)NMe(2), R = Me; 1 e: X = CONH(CH(2))(2)NMe(3) (+), R = Me; 1 f: X = H, R = F), have been tested as catalysts for the oxidative decolorization of Orange II and Sudan III dyes by hydrogen peroxide and tert-butyl hydroperoxide in the presence of micelles that are neutral (Triton X-100), positively charged (cetyltrimethylammonium bromide, CTAB), and negatively charged (sodium dodecyl sulfate, SDS). The previously reported mechanism of catalysis involves the formation of an oxidized intermediate from 1 and ROOH (k(I)) followed by dye bleaching (k(II)). The micellar effects on k(I) and k(II) have been separately studied and analyzed by using the Berezin pseudophase model of micellar catalysis. The largest micellar acceleration in terms of k(I) occurs for the 1 a-tBuOOH-CTAB system. At pH 9.0-10.5 the rate constant k(I) increased by approximately five times with increasing CTAB concentration and then gradually decreased. There was no acceleration at higher pH, presumably owing to the deprotonation of the axial water ligand of 1 a in this pH range. The k(I) value was only slightly affected by SDS (in the oxidation of Orange II), but was strongly decelerated by Triton X-100. No oxidation of the water-insoluble, hydrophobic dye Sudan III was observed in the presence of the SDS micelles. The k(II) value was accelerated by cationic CTAB micelles when the hydrophobic primary oxidant tert-butyl hydroperoxide was used. It is hypothesized that tBuOOH may affect the CTAB micelles and increase the binding of the oxidized catalysts. The tBuOOH-CTAB combination accelerated both of the catalysis steps k(I) and k(II).
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Affiliation(s)
- Deboshri Banerjee
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
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Ryabov AD, Collins TJ. Mechanistic considerations on the reactivity of green FeIII-TAML activators of peroxides. ADVANCES IN INORGANIC CHEMISTRY 2009. [DOI: 10.1016/s0898-8838(09)00208-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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32
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Morris RH. Asymmetric hydrogenation, transfer hydrogenation and hydrosilylation of ketones catalyzed by iron complexes. Chem Soc Rev 2009; 38:2282-91. [DOI: 10.1039/b806837m] [Citation(s) in RCA: 653] [Impact Index Per Article: 43.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Ghosh A, Mitchell DA, Chanda A, Ryabov AD, Popescu DL, Upham EC, Collins GJ, Collins TJ. Catalase-peroxidase activity of iron(III)-TAML activators of hydrogen peroxide. J Am Chem Soc 2008; 130:15116-26. [PMID: 18928252 DOI: 10.1021/ja8043689] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Exceptionally high peroxidase-like and catalase-like activities of iron(III)-TAML activators of H 2O 2 ( 1: Tetra-Amidato-Macrocyclic-Ligand Fe (III) complexes [ F e{1,2-X 2C 6H 2-4,5-( NCOCMe 2 NCO) 2CR 2}(OH 2)] (-)) are reported from pH 6-12.4 and 25-45 degrees C. Oxidation of the cyclometalated 2-phenylpyridine organometallic complex, [Ru (II)( o-C 6H 4py)(phen) 2]PF 6 ( 2) or "ruthenium dye", occurs via the equation [ Ru II ] + 1/2 H 2 O 2 + H +-->(Fe III - TAML) [ Ru III ] + H 2 O, following a simple rate law rate = k obs (per)[ 1][H 2O 2], that is, the rate is independent of the concentration of 2 at all pHs and temperatures studied. The kinetics of the catalase-like activity (H 2 O 2 -->(Fe III - TAML) H 2 O + 1/2 O 2) obeys a similar rate law: rate = k obs (cat)[ 1][H 2O 2]). The rate constants, k obs (per) and k obs (cat), are strongly and similarly pH dependent, with a maximum around pH 10. Both bell-shaped pH profiles are quantitatively accounted for in terms of a common mechanism based on the known speciation of 1 and H 2O 2 in this pH range. Complexes 1 exist as axial diaqua species [FeL(H 2O) 2] (-) ( 1 aqua) which are deprotonated to afford [FeL(OH)(H 2O)] (2-) ( 1 OH) at pH 9-10. The pathways 1 aqua + H 2O 2 ( k 1), 1 OH + H 2O 2 ( k 2), and 1 OH + HO 2 (-) ( k 4) afford one or more oxidized Fe-TAML species that further rapidly oxidize the dye (peroxidase-like activity) or a second H 2O 2 molecule (catalase-like activity). This mechanism is supported by the observations that (i) the catalase-like activity of 1 is controllably retarded by addition of reducing agents into solution and (ii) second order kinetics in H 2O 2 has been observed when the rate of O 2 evolution was monitored in the presence of added reducing agents. The performances of the 1 complexes in catalyzing H 2O 2 oxidations are shown to compare favorably with the peroxidases further establishing Fe (III)-TAML activators as miniaturized enzyme replicas with the potential to greatly expand the technological utility of hydrogen peroxide.
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Affiliation(s)
- Anindya Ghosh
- Department of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, USA
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