Structural, Mechanistic, and Ultradilute Catalysis Portrayal of Substrate Inhibition in the TAML–Hydrogen Peroxide Catalytic Oxidation of the Persistent Drug and Micropollutant, Propranolol

Somasundar, Yogesh; Lan-sun, Shen; Hoane, Alexis G.; Tang, Liang; Mills, Matthew R.; Burton, Abigail E.; Ryabov, Alexander D.; Collins, Terrence J.

doi:10.1021/jacs.8b08108

Cited by 23 publications

(40 citation statements)

References 88 publications

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“…[4,13] Analysis of the products of 2-catalyzed degradation of imidacloprid by ion chromatography suggests that imidacloprid undergoes deep fragmentation as only acetate and oxamate were detected ( Figure S2) after running the reaction for almost1 0h.T he chromatogram peak with the retention time of 15 min, whicha ppears after acetate and oxamate, is believed to be duetoc hloride impurity. [11]…”

Section: Taml-catalyzed Oxidation Of Imidacloprid:products and Catalymentioning

confidence: 99%

“…Substrate inhibition is af eature of the catalysis by TAML activators. [11] The phenomenon was first observed in the 5-catalyzed oxidative bleaching of the pinacyanol chloride (PNC) dyeb y H 2 O 2 . [18] The reactionk inetics differed profoundly from that typical of TAML activators rate law as in Eq.…”

Section: Substrate Inhibition As Am Echanistic Optionmentioning

confidence: 99%

“…The very case of substrate inhibition has been recently detailed in the mechanistic study of the TAML-catalyzed oxidative degradationo fp ropranololb y H 2 O 2 . [11] Propranololi nhibits its own TAML/H 2 O 2 oxidation by binding to the catalyst resting state to form an associate [Fe III ,Substrate] (Eq. (4)), which is less reactivet han the Fe III resting state towardH 2 O 2 .T he catalyst-propranolol associates have been isolated from dilute aqueous solutions and characterized by ESI-MS, florescence, FTIR, and 1 HNMR spectroscopies.…”

Section: Substrate Inhibition As Am Echanistic Optionmentioning

confidence: 99%

“…(4)), which is less reactivet han the Fe III resting state towardH 2 O 2 .T he catalyst-propranolol associates have been isolated from dilute aqueous solutions and characterized by ESI-MS, florescence, FTIR, and 1 HNMR spectroscopies. [11] Fe III þ Substrate Ð½Fe III ,Substrate ðKÞ ð4Þ…”

Section: Substrate Inhibition As Am Echanistic Optionmentioning

confidence: 99%

“…This concentration regime was selected to deal with elimination of tiny amountso fi midacloprid because such may bring about the highestd amage to living species through the mechanism of non-linear dose response. [10] Attempts to account for zero-order kinetics in the catalystc oncentrationt hrough known properties of TAML activators, among which substrate inhibition [11] is essential, have also been made. In the Supporting Information, we also show al ow order in TAML catalyst for the 3-catalyzed oxidation of 3-methyl-4-nitrophenolb yH 2 O 2 .…”

Section: Introductionmentioning

confidence: 99%

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Zero‐Order Catalysis in TAML‐Catalyzed Oxidation of Imidacloprid, a Neonicotinoid Pesticide

Warner

Somasundar

Weng

et al. 2020

Chemistry A European J

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Bis‐sulfonamide bis‐amide TAML activator [Fe{4‐NO2C6H3‐1,2‐(NCOCMe2NSO2)2CHMe}]− (2) catalyzes oxidative degradation of the oxidation‐resistant neonicotinoid insecticide, imidacloprid (IMI), by H2O2 at pH 7 and 25 °C, whereas the tetrakis‐amide TAML [Fe{4‐NO2C6H3‐1,2‐(NCOCMe2NCO)2CF2}]− (1), previously regarded as the most catalytically active TAML, is inactive under the same conditions. At ultra‐low concentrations of both imidacloprid and 2, 62 % of the insecticide was oxidized in 2 h, at which time the catalyst is inactivated; oxidation resumes on addition of a succeeding aliquot of 2. Acetate and oxamate were detected by ion chromatography, suggesting deep oxidation of imidacloprid. Explored at concentrations [2]≥[IMI], the reaction kinetics revealed unusually low kinetic order in 2 (0.164±0.006), which is observed alongside the first order in imidacloprid and an ascending hyperbolic dependence in [H2O2]. Actual independence of the reaction rate on the catalyst concentration is accounted for in terms of a reversible noncovalent binding between a substrate and a catalyst, which usually results in substrate inhibition when [catalyst]≪[substrate] but explains the zero order in the catalyst when [2]>[IMI]. A plausible mechanism of the TAML‐catalyzed oxidations of imidacloprid is briefly discussed. Similar zero‐order catalysis is presented for the oxidation of 3‐methyl‐4‐nitrophenol by H2O2, catalyzed by the TAML analogue of 1 without a NO2‐group in the aromatic ring.

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Section: Taml-catalyzed Oxidation Of Imidacloprid:products and Catalymentioning

confidence: 99%

Section: Substrate Inhibition As Am Echanistic Optionmentioning

confidence: 99%

Section: Substrate Inhibition As Am Echanistic Optionmentioning

confidence: 99%

Section: Substrate Inhibition As Am Echanistic Optionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Zero‐Order Catalysis in TAML‐Catalyzed Oxidation of Imidacloprid, a Neonicotinoid Pesticide

Warner

Somasundar

Weng

et al. 2020

Chemistry A European J

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Synthesis of novel acyclic and multiple phenyl iron tetraamino ligand catalysts and its catalytic activity for degradation of dye wastewater by H₂O₂

Zhou

Zhao

et al. 2021

Applied Organom Chemis

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We need a practical, inexpensive, and green way to reduce the environmental pollutants, especially for dye wastewater. The discharge of industrial wastewater such as organic dyes will cause serious pollution to water bodies, thereby affecting people's lives. In this work, we designed and successfully synthesized four new ligand catalysts. The total outputs of diamide diamino iron ligand compounds A and B are 71.33% and 61.39%, respectively. The total outputs of polyaromatic iron tetraamido macrocyclic ligand (TAML) compounds C and D are 38.49% and 49.11%, respectively. The catalytic effects of four catalysts on the degradation of dye wastewater by hydrogen peroxide oxidation were studied and compared with the second‐generation FeIII‐TAML catalyst. The experimental results showed that acyclic catalyst A and B has good catalytic effect. For methylene blue, methyl orange, rhodamine B three dyes wastewater, under the conditions of 20°C, Ccatalyst A = 0.056–0.28 mM and Chydrogen peroxide = 33 mM, the decolorization rate and chemical oxygen demand (COD) removal rate are 81.53%–97.58% and 52.2%–60.7%, respectively. Under the condition of 20°C, Ccatalyst B = 0.75 mM and Chydrogen peroxide = 33 mM, the decolorization rate and COD removal rate are 48.33%–80.33% and 44.6%–57.8%, respectively.

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Predicting Properties of Iron(III) TAML Activators of Peroxides from Their III/IV and IV/V Reduction Potentials or a Lost Battle to Peroxidase

Somasundar

Lan-sun

Hoane

et al. 2020

Chemistry A European J

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Ac yclic voltammetry study of as eries of iron(III) TAML activators of peroxides of severalg enerationsi na cetonitrile as solvent reveals reversible or quasireversibleF e III/IV and Fe IV/V anodic transitions, the formal reduction potentials (E8')f or which are observed in the ranges 0.4-1.2 and 1.4-1.6 V, respectively,v ersusA g/AgCl. The slope of 0.33 for a linear E8'(IV/V) against E8'(III/IV) plot suggests that the TAML ligand system plays ab iggerr ole in the Fe III/IV transition, whereas the second electron transfer is to al arger extenta n iron-centered phenomenon. The reduction potentials appear to be ac onvenient tool for analysis of variousp roperties of iron TAML activators in terms of linear free energy relationships (LFERs). The values of E8'(III/IV) and E8'(IV V À1)c orrelate 1) with the pK a values of the axial aqua ligand of iron(III) TAMLs with slopes of 0.28 and 0.06 V, respectively;2)with the Stern-Volmer constants K SV for the quenching of fluorescence of propranolol, am icropollutant of broad concern; 3) with the calculated ionization potentials of Fe III and Fe IV TAMLs;a nd 4) with rate constants k I and k II for the oxidation of the restingi ron(III) TAML state by H 2 O 2 and reactions of the active forms of TAMLs formed with donors of electrons S, respectively.I nterestingly,s lopes of log k II versus E8'(III/IV) plots are lower for fast-to-oxidize St han for slow-to-oxidize S. The log k I versus E8'(III/IV) plot suggeststhat the manmade TAML catalyst can never be as reactive toward H 2 O 2 as a horseradish peroxidase enzyme.

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Structural, Mechanistic, and Ultradilute Catalysis Portrayal of Substrate Inhibition in the TAML–Hydrogen Peroxide Catalytic Oxidation of the Persistent Drug and Micropollutant, Propranolol

Cited by 23 publications

References 88 publications

Zero‐Order Catalysis in TAML‐Catalyzed Oxidation of Imidacloprid, a Neonicotinoid Pesticide

Zero‐Order Catalysis in TAML‐Catalyzed Oxidation of Imidacloprid, a Neonicotinoid Pesticide

Synthesis of novel acyclic and multiple phenyl iron tetraamino ligand catalysts and its catalytic activity for degradation of dye wastewater by H₂O₂

Predicting Properties of Iron(III) TAML Activators of Peroxides from Their III/IV and IV/V Reduction Potentials or a Lost Battle to Peroxidase

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Structural, Mechanistic, and Ultradilute Catalysis Portrayal of Substrate Inhibition in the TAML–Hydrogen Peroxide Catalytic Oxidation of the Persistent Drug and Micropollutant, Propranolol

Cited by 23 publications

References 88 publications

Zero‐Order Catalysis in TAML‐Catalyzed Oxidation of Imidacloprid, a Neonicotinoid Pesticide

Zero‐Order Catalysis in TAML‐Catalyzed Oxidation of Imidacloprid, a Neonicotinoid Pesticide

Synthesis of novel acyclic and multiple phenyl iron tetraamino ligand catalysts and its catalytic activity for degradation of dye wastewater by H2O2

Predicting Properties of Iron(III) TAML Activators of Peroxides from Their III/IV and IV/V Reduction Potentials or a Lost Battle to Peroxidase

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Synthesis of novel acyclic and multiple phenyl iron tetraamino ligand catalysts and its catalytic activity for degradation of dye wastewater by H₂O₂