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Skipworth T, Klaine S, Zhang R. Photochemical generation and reactivity of a new phthalocyanine-manganese-oxo intermediate. Chem Commun (Camb) 2023; 59:6540-6543. [PMID: 37161771 DOI: 10.1039/d3cc01275a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The first phthalocyanine-manganese-oxo intermediate was successfully generated by visible-light photolysis of chlorate or nitrite manganese(III) precursors, and its reactivity towards organic substrates was kinetically probed and compared with other related porphyrin-metal-oxo intermediates.
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Affiliation(s)
- Tristan Skipworth
- Department of Chemistry, Western Kentucky University, 1906 College Heights Blvd., Bowling Green, Kentucky, USA.
| | - Seth Klaine
- Department of Chemistry, Western Kentucky University, 1906 College Heights Blvd., Bowling Green, Kentucky, USA.
| | - Rui Zhang
- Department of Chemistry, Western Kentucky University, 1906 College Heights Blvd., Bowling Green, Kentucky, USA.
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2
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Skipworth T, Khashimov M, Ojo I, Zhang R. Kinetics of chromium(V)-oxo and chromium(IV)-oxo porphyrins: Reactivity and mechanism for sulfoxidation reactions. J Inorg Biochem 2022; 237:112006. [PMID: 36162208 DOI: 10.1016/j.jinorgbio.2022.112006] [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: 07/07/2022] [Revised: 09/13/2022] [Accepted: 09/13/2022] [Indexed: 01/18/2023]
Abstract
In this work, chromium(IV)-oxo porphyrins [CrIV(Por)(O)] (2) (Por = porphyrin) were produced either by oxidation of [CrIII(Por)Cl] (1) with iodobenzene diacetate or visible light photolysis of porphyrin‑chromium(III) chlorates. Subsequent oxidation of 2 with silver perchlorate gave chromium(V)-oxo porphyrins [CrV(Por)(O)](ClO4) (3) in three porphyrin ligands, including 5,10,15,20-tetramesitylporphyrin(TMP, a), 5,10,15,20-tetrakis(2,6-difluorophenyl)porphyrin(TDFPP, b), and 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (TPFPP, c). Complexes 2 and 3 reacted with thioanisoles to produce the corresponding sulfoxides, and their kinetics of sulfoxidation reactions with a series of aryl methyl sulfides(thioanisoles) were studied in organic solutions. Chromium(V)-oxo porphyrins are several orders of magnitudes more reactive than chromium(IV)-oxo species, and representative second-order rate constants (kox) for the oxidation of thioansole are (0.40 ± 0.01) M-1 s-1 (3a), and (2.82 ± 0.20) × 102 M-1 s-1 (3b), and (2.20 ± 0.01) × 103 M-1 s-1 (3c). The order of reactivity for 2 and 3 follows TPFPP > TDFPP > TMP, in agreement with the electrophilic nature of metal-oxo complexes. Hammett analyses indicate significant charge transfer in the transition states for oxidation of para-substituted thioanisoles by [CrV(Por)(O)]+. The ρ+ constants are -1.69 for 3a, -2.63 for 3b, and - 2.89 for 3c, respectively, mirror values found previously for related metal-oxo species. A mechanism involving the electrophilic attack of the CrV-oxo at sulfides to form a sulfur cation intermediate in the rate-determining step is suggested. Competition studies with chromium(III) porphyrin chloride and PhI(OAc)2 gave relative rate constants for oxidations of competing thioanisoles that closely match ratios of absolute rate constants from chromium(V)-oxo species, which are true oxidants under catalytic conditions.
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Affiliation(s)
- Tristan Skipworth
- Department of Chemistry, Western Kentucky University, 1906 College Heights Blvd #11079, Bowling Green, KY 42101-1079, United States of America
| | - Mardan Khashimov
- Department of Chemistry, Western Kentucky University, 1906 College Heights Blvd #11079, Bowling Green, KY 42101-1079, United States of America
| | - Iyanu Ojo
- Department of Chemistry, Western Kentucky University, 1906 College Heights Blvd #11079, Bowling Green, KY 42101-1079, United States of America
| | - Rui Zhang
- Department of Chemistry, Western Kentucky University, 1906 College Heights Blvd #11079, Bowling Green, KY 42101-1079, United States of America.
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3
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Tang Y, Li MN, Huang ZY, Liu HY, Xiao XY, Zhang SQ. Synthesis of Metal Xanthene‐Bridged Bis‐corroles and their Catalytic Activity in Aerobic Baeyer‐Villiger Oxidation Reaction. ASIAN J ORG CHEM 2022. [DOI: 10.1002/ajoc.202200349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yan Tang
- South China University of Technology School of Chemistry and Chemical Engineering CHINA
| | - Meng-Ni Li
- South China University of Technology School of Chemistry and Chemical Engineering CHINA
| | - Zhen-Yu Huang
- South China University of Technology School of Chemistry and Chemical Engineering CHINA
| | - Hai-Yang Liu
- South China University of Technology Department of Chemistry 381# Wushan Road 510641 Guangzhou CHINA
| | - Xin-Yan Xiao
- South China University of Technology School of Chemistry and Chemical Engineering CHINA
| | - Si-Quan Zhang
- Guangdong Baomo Biochemical Com. Ltd. Technology Department CHINA
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4
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Van Trieste GP, Reibenspies JH, Chen YS, Sengupta D, Thompson RR, Powers DC. Oxygen-atom transfer photochemistry of a molecular copper bromate complex. Chem Commun (Camb) 2022; 58:12608-12611. [DOI: 10.1039/d2cc04403j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the synthesis and oxygen-atom transfer (OAT) photochemistry of [Cu(tpa)BrO3]ClO4.
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Affiliation(s)
| | | | - Yu-Sheng Chen
- ChemMatCARS, University of Chicago, Argonne, IL 60439, USA
| | - Debabrata Sengupta
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
| | - Richard R. Thompson
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
| | - David C. Powers
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
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5
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Visible light generation of high-valent metal-oxo intermediates and mechanistic insights into catalytic oxidations. J Inorg Biochem 2020; 212:111246. [PMID: 33059321 DOI: 10.1016/j.jinorgbio.2020.111246] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/07/2020] [Accepted: 08/22/2020] [Indexed: 11/21/2022]
Abstract
High-valent metal-oxo complexes play central roles as active oxygen atom transfer (OAT) agents in many enzymatic and synthetic oxidation catalysis. This review focuses on our recent advances in application of photochemical approaches to probe the oxidizing metal-oxo species with different metals and macrocyclic ligands. Under visible light irradiation, a variety of important metal-oxo species including iron-oxo porphyrins, manganese-oxo porphyrin/corroles, ruthenium-oxo porphyrins, and chromium-oxo salens have been successfully generated. Kinetical studies in real time have provided mechanistic insights as to the reactivity and reaction pathways of the metal-oxo intermediates in their oxidation reactions. In photo-induced ligand cleavage reactions, metals in n+ oxidation state with the oxygen-containing ligands bromate, chlorate, or nitrites were photolyzed. Homolytic cleavage of the O-X bond in the ligand gives (n + 1)+ oxidation state metal-oxo species, and heterolytic cleavage gives (n + 2)+ oxidation state metal-oxo species. In photo-disproportionation reactions, reactive Mn+1-oxo species can be formed by photolysis of μ-oxo dimeric Mn+ complexes with the concomitant formation of Mn-1 products. Importantly, the oxidation of Mn-1 products by molecular oxygen (O2) to regenerate the μ-oxo dimeric Mn+ complexes in photo-disproportionation reactions represents an attractive and green catalytic cycle for the development of photocatalytic aerobic oxidations.
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Klaine S, Fung Lee N, Dames A, Zhang R. Visible light generation of chromium(V)-oxo salen complexes and mechanistic insights into catalytic sulfide oxidation. Inorganica Chim Acta 2020. [DOI: 10.1016/j.ica.2020.119681] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Klaine S, Bratcher F, Winchester CM, Zhang R. Formation and kinetic studies of manganese(IV)-oxo porphyrins: Oxygen atom transfer mechanism of sulfide oxidations. J Inorg Biochem 2019; 204:110986. [PMID: 31924588 DOI: 10.1016/j.jinorgbio.2019.110986] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 12/27/2019] [Accepted: 12/28/2019] [Indexed: 11/26/2022]
Abstract
Visible light irradiation of photo-labile porphyrin-manganese(III) chlorates or bromates (2) produced manganese(IV)-oxo porphyrins [MnIV(Por)(O)] (Por = porphyrin) (3) in three porphyrin ligands. The same oxo species 3 were also formed by chemical oxidation of the corresponding manganese(III) precursors (1) with iodobenzene diacetate, i.e. PhI(OAc)2. The systems under study include 5,10,15,20-tetra(pentafluorophenyl)porphyrin‑manganese(IV)-oxo (3a), 5,10,15,20-tetra(2,6-difluorophenyl)porphyrin‑manganese(IV)-oxo (3b), and 5,10,15,20-tetramesitylporphyrin‑manganese(IV)-oxo (3c). As expected, complexes 3 reacted with thioanisoles to produce the corresponding sulfoxides and over-oxidized sulfones. The kinetics of oxygen atom transfer (OAT) reactions of these generated 3 with aryl sulfides were studied in CH3CN solutions. Second-order rate constants for sulfide oxidation reactions are comparable to those of alkene epoxidations and activated CH bond oxidations by the same oxo species 3. For a given substrate, the reactivity order for the manganese(IV)-oxo species was 3a > 3b > 3c, consistent with expectations on the basis of the electron-withdrawing capacity of the porphyrin macrocycles. Free-energy Hammett analyses gave near-linear correlations with σ values, indicating no significant positive charge developed at the sulfur during the oxidation process. The mechanistic results strongly suggest [MnIV(Por)(O)] reacts as a direct OAT agent towards sulfide substrates through a manganese(II) intermediate that was detected in this work. However, an alternative pathway that involves a disproportionation of 3 to form a higher oxidized manganese(V)-oxo species may be significant when less reactive substrates are present. The competition product studies with the Hammett correlation plot confirmed that the observed manganese(IV)-oxo species is not the true oxidant for the sulfide oxidations catalyzed by manganese(III) porphyrins with PhI(OAc)2.
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Affiliation(s)
- Seth Klaine
- Department of Chemistry, Western Kentucky University, 1906 College Heights Blvd #11079, Bowling Green, KY 42101-1079, United States of America
| | - Fox Bratcher
- Department of Chemistry, Western Kentucky University, 1906 College Heights Blvd #11079, Bowling Green, KY 42101-1079, United States of America
| | - Charles M Winchester
- Department of Chemistry, Western Kentucky University, 1906 College Heights Blvd #11079, Bowling Green, KY 42101-1079, United States of America
| | - Rui Zhang
- Department of Chemistry, Western Kentucky University, 1906 College Heights Blvd #11079, Bowling Green, KY 42101-1079, United States of America.
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Lee NF, Patel D, Liu H, Zhang R. Insights from kinetic studies of photo-generated compound II models: Reactivity toward aryl sulfides. J Inorg Biochem 2018; 183:58-65. [PMID: 29550659 DOI: 10.1016/j.jinorgbio.2018.03.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 03/05/2018] [Accepted: 03/08/2018] [Indexed: 10/17/2022]
Abstract
Iron(IV)-oxo porphyrins [FeIV(Por)O] (Por = poprhyrin), commonly called compound II models, were produced in three electron-deficient ligands by visible light irradiation of highly photo-labile porphyrin-iron(III) bromates or chlorates. The kinetics of oxygen transfer atom (OAT) reactions with aryl sulfides by these photo-generated [FeIV(Por)O] (3) were studied in CH3CN solutions. The iron(IV)-oxo porphyrins under study include 5,10,15,20-tetra(2,6-dichlorophenyl)porphyrin-iron(IV)-oxo (3a), 5,10,15,20-tetra(2,6-difluorophenyl)porphyrin-iron(IV)-oxo (3b), and 5,10,15,20-tetra(pentafluorophenyl)porphyrin-iron(IV)-oxo (3c). As expected, complexes 3 were competent oxidants and reacted rapidly with thioanisoles to give the corresponding sulfoxides with minor over-oxidation sulfones. Apparent second-order rate constants determined under pseudo-first-order conditions for sulfide oxidation reactions are (9.8 ± 0.1) × 102-(3.7 ± 0.3) × 101 M-1 s-1, which are 3 to 4 orders of magnitude greater in comparison to those of alkene epoxidations and activated CH bond oxidations by the same oxo species. Conventional Hammett analyses gave non-linear correlations, indicating no significant charge developed at the sulfur during the oxidation process. For a given substrate, the reactivity order for the iron(IV)-oxo species was 3c < 3b < 3a, which is inverted from expectations on the basis of the electron-withdrawing capacity of the porphyrin macrocycles. The absolute rate constants from kinetic studies provided insights into the transient oxidants in catalytic reactions under turnover conditions where actual reactive intermediates are not observable. Our kinetic and catalytic competition results strongly suggest that 3 may undergo a disproportionation reaction to form a higher oxidized iron(IV)-oxo porphyrin radical cations as the true oxidant.
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Affiliation(s)
- Ngo Fung Lee
- Department of Chemistry, Western Kentucky University, 1906 College Heights Blvd #11079, Bowling Green, KY 42101-1079, United States
| | - Dharmesh Patel
- Department of Chemistry, Western Kentucky University, 1906 College Heights Blvd #11079, Bowling Green, KY 42101-1079, United States
| | - Haiyan Liu
- Department of Chemistry, Western Kentucky University, 1906 College Heights Blvd #11079, Bowling Green, KY 42101-1079, United States
| | - Rui Zhang
- Department of Chemistry, Western Kentucky University, 1906 College Heights Blvd #11079, Bowling Green, KY 42101-1079, United States.
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Baglia RA, Zaragoza JPT, Goldberg DP. Biomimetic Reactivity of Oxygen-Derived Manganese and Iron Porphyrinoid Complexes. Chem Rev 2017; 117:13320-13352. [PMID: 28991451 PMCID: PMC6058703 DOI: 10.1021/acs.chemrev.7b00180] [Citation(s) in RCA: 204] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Heme proteins utilize the heme cofactor, an iron porphyrin, to perform a diverse range of reactions including dioxygen binding and transport, electron transfer, and oxidation/oxygenations. These reactions share several key metalloporphyrin intermediates, typically derived from dioxygen and its congeners such as hydrogen peroxide. These species are composed of metal-dioxygen, metal-superoxo, metal-peroxo, and metal-oxo adducts. A wide variety of synthetic metalloporphyrinoid complexes have been synthesized to generate and stabilize these intermediates. These complexes have been studied to determine the spectroscopic features, structures, and reactivities of such species in controlled and well-defined environments. In this Review, we summarize recent findings on the reactivity of these species with common porphyrinoid scaffolds employed for biomimetic studies. The proposed mechanisms of action are emphasized. This Review is organized by structural type of metal-oxygen intermediate and broken into subsections based on the metal (manganese and iron) and porphyrinoid ligand (porphyrin, corrole, and corrolazine).
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Affiliation(s)
- Regina A. Baglia
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - Jan Paulo T. Zaragoza
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
| | - David P. Goldberg
- Department of Chemistry, The Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, United States
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Lee NF, Malone J, Jeddi H, Kwong KW, Zhang R. Visible-light photolysis of corrole-manganese(IV) nitrites to generate corrole-manganese(V)-oxo complexes. INORG CHEM COMMUN 2017. [DOI: 10.1016/j.inoche.2017.05.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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11
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Nasrollahi R, Zakavi S. Evidence on the Nature of the Active Oxidants Involved in the Oxidation of Alcohols with Oxone Catalyzed by an Electron‐Deficient Manganese Porphyrin: A Combined Kinetic and Mechanistic Study. Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201601488] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Rahele Nasrollahi
- Institute for Advanced Studies in Basic Sciences (IASBS) 45137‐66731 Zanjan Iran
| | - Saeed Zakavi
- Institute for Advanced Studies in Basic Sciences (IASBS) 45137‐66731 Zanjan Iran
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Kwong KW, Patel D, Malone J, Lee NF, Kash B, Zhang R. An investigation of ligand effects on the visible light-induced formation of porphyrin–iron(iv)-oxo intermediates. NEW J CHEM 2017. [DOI: 10.1039/c7nj03296j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Depending on the structure of the porphyrin ligands, the visible light photolysis of porphyrin–iron(iii) bromates produced iron(iv)-oxo radical cations or iron(iv)-oxo porphyrins, permitting direct kinetic studies of their oxidation reactions.
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Affiliation(s)
- Ka Wai Kwong
- Department of Chemistry
- Western Kentucky University
- Bowling Green
- USA
| | - Dharmesh Patel
- Department of Chemistry
- Western Kentucky University
- Bowling Green
- USA
| | - Jonathan Malone
- Department of Chemistry
- Western Kentucky University
- Bowling Green
- USA
| | - Ngo Fung Lee
- Department of Chemistry
- Western Kentucky University
- Bowling Green
- USA
| | - Benjamin Kash
- Department of Chemistry
- Western Kentucky University
- Bowling Green
- USA
| | - Rui Zhang
- Department of Chemistry
- Western Kentucky University
- Bowling Green
- USA
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Chen TH, Kwong KW, Lee NF, Ranburger D, Zhang R. Highly efficient and chemoselective oxidation of sulfides catalyzed by iron(III) corroles with iodobenzene diacetate. Inorganica Chim Acta 2016. [DOI: 10.1016/j.ica.2016.07.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Corcos AR, Pap JS, Yang T, Berry JF. A Synthetic Oxygen Atom Transfer Photocycle from a Diruthenium Oxyanion Complex. J Am Chem Soc 2016; 138:10032-40. [PMID: 27406958 PMCID: PMC5972014 DOI: 10.1021/jacs.6b05942] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Three new diruthenium oxyanion complexes have been prepared, crystallographically characterized, and screened for their potential to photochemically unmask a reactive Ru-Ru═O intermediate. The most promising candidate, Ru2(chp)4ONO2 (4, chp = 6-chloro-2-hydroxypyridinate), displays a set of signals centered around m/z = 733 amu in its MALDI-TOF mass spectrum, consistent with the formation of the [Ru2(chp)4O](+) ([6](+)) ion. These signals shift to 735 amu in 4*, which contains an (18)O-labeled nitrate. EPR spectroscopy and headspace GC-MS analysis indicate that NO2(•) is released upon photolysis of 4, also consistent with the formation of 6. Photolysis of 4 in CH2Cl2 at room temperature in the presence of excess PPh3 yields OPPh3 in 173% yield; control experiments implicate 6, NO2(•), and free NO3(-) as the active oxidants. Notably, Ru2(chp)4Cl (3) is recovered after photolysis. Since 3 is the direct precursor to 4, the results described herein constitute the first example of a synthetic cycle for oxygen atom transfer that makes use of light to generate a putative metal oxo intermediate.
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Affiliation(s)
- Amanda R. Corcos
- Department of Chemistry, University of Wisconsin – Madison, 1101 University Ave., Madison, Wisconsin, 53706, USA
| | - József S. Pap
- Department of Chemistry, University of Wisconsin – Madison, 1101 University Ave., Madison, Wisconsin, 53706, USA
| | - Tzuhsiung Yang
- Department of Chemistry, University of Wisconsin – Madison, 1101 University Ave., Madison, Wisconsin, 53706, USA
| | - John F. Berry
- Department of Chemistry, University of Wisconsin – Madison, 1101 University Ave., Madison, Wisconsin, 53706, USA
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Ka WK, Ngo FL, Ranburger D, Malone J, Zhang R. Visible light-induced formation of corrole-manganese(V)-oxo complexes: Observation of multiple oxidation pathways. J Inorg Biochem 2016; 163:39-44. [PMID: 27513949 DOI: 10.1016/j.jinorgbio.2016.08.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 08/02/2016] [Accepted: 08/04/2016] [Indexed: 11/19/2022]
Abstract
Two manganese(V)-oxo corroles [MnV(Cor)O] that differ in their electronic environments were produced by visible light irradiation of highly photo-labile corrole-manganese(IV) bromates. The corrole ligands under study include 5,10,15-tris(pentafluorophenyl)corrole (TPFC), and 5,10,15-triphenylcorrole (TPC). The kinetics of oxygen transfer atom (OAT) reactions with various organic reductants by these photo-generated MnV(Cor)O were also studied in CH3CN and CH2Cl2 solutions. MnV(Cor)O exhibits remarkable solvent and ligand effect on its reactivity and spectral behavior. In the more electron-deficient TPFC system and in the polar solvent CH3CN, MnV(Cor)O returned MnIII corrole in the end of oxidation reactions. However, in the less polar solvent CH2Cl2 or in the less electron-deficient TPC system, MnIV product was formed instead of MnIII. Furthermore, with the same substrates and in the same solvent, the order of reactivity of MnV(Cor)O was TPC>TPFC, which is inverted from that expected based on the electron-demand of corrole ligands. Our spectral and kinetic results in this study provide compelling evidence in favor of multiple oxidation pathways, where MnV(Cor)O may serve as direct two-electron oxidant or undergo a disproportionation reaction to form a manganese(VI)-oxo corrole as the true oxidant. The choice of pathways is strongly dependent on the nature of the solvent and the corrole ligand.
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Affiliation(s)
- Wai Kwong Ka
- Department of Chemistry, Western Kentucky University, Bowling Green, KY 42101-1079, USA
| | - Fung Lee Ngo
- Department of Chemistry, Western Kentucky University, Bowling Green, KY 42101-1079, USA
| | - Davis Ranburger
- Department of Chemistry, Western Kentucky University, Bowling Green, KY 42101-1079, USA
| | - Jonathan Malone
- Department of Chemistry, Western Kentucky University, Bowling Green, KY 42101-1079, USA
| | - Rui Zhang
- Department of Chemistry, Western Kentucky University, Bowling Green, KY 42101-1079, USA.
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