Sodium Periodate as a Selective Oxidant for Diclofenac Sodium in Alkaline Medium: A Quantum Chemical Approach

Diclofenac sodium is a well known anti-inflammatory drug. It has also been proclaimed to exhibit adverse effects on aquatic animals through sewage and waste water treatment plants. Kinetic and mechanistic studies of the novel oxidation of diclofenac sodium (DFS) by sodium periodate were discussed with an emphasis on structure and reactivity by using kinetic and computational approach. The proposed work had been studied in alkaline medium at 303 K and at a constant ionic strength of 0.60 mol.dm−3. Formation of [2-(2,6-dicloro-phynylamino)-phenyl]-methanol as the oxidation product of DFS is confirmed with the help of structure elucidation. The active species of catalyst, oxidant and oxidation products were recognized by UV and IR spectral studies. Proton inventory studies in H2O−D2O mixtures had been shown the involvement of a single exchangeable proton of OH− ion in the transition state. All quantum chemical calculations were executed at level of density functional theory (DFT) with B3LYP function using 6-31G (d,p) basis atomic set for the validation of structure, reaction and mechanism. Molecular orbital energies, nonlinear optical properties, bond length, bond angles, reactivity, electrophilic and nucleophilic regions were delineated. Influence of various reactants on rate of chemical reaction were also ascertained and elucidated spectro-photometrically. Activation parameters have been assessed using Arrhenius-Eyring plots. A suitable mechanism consistent with observed kinetic results had been implicated and rate law deduced. Copyright © 2020 BCREC Group. All rights reserved

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Mechanistic aspects of oxidation on L-tyrosine by diperiodatocuprate(III) complex in alkali media: a kinetic model

Open Chemistry ◽

10.2478/s11532-009-0085-0 ◽

2009 ◽

Vol 7 (4) ◽

pp. 929-937 ◽

Cited By ~ 1

Author(s):

Nagaraj Shetti ◽

Rajesh Hegde ◽

Sharanappa. Nandibewoor

Keyword(s):

Alkaline Medium ◽

Activation Parameters ◽

Spectral Studies ◽

Slow Step ◽

Isokinetic Temperature ◽

Thermodynamic Quantities ◽

Radical Intermediate ◽

Different Temperatures ◽

Reactive Oxidant ◽

Reaction Constants

AbstractOxidation of an amino acid, L-tyrosine (L-Tyr) by diperiodatocuprate(III) (DPC) in alkaline medium at a constant ionic strength of 0.1 mol dm−3 was studied spectrophotometrically at different temperatures (288.1–313.1 K). The reaction between DPC and L-Tyr in alkaline medium exhibits 1:4 stoichiometry (L-Tyr:DPC). Intervention of free radicals was observed in the reaction. Based on the observed orders and experimental evidence, a mechanism involving monoperiodatocuprate(III) (MPC) as the reactive oxidant species has been proposed. A suitable mechanism is proposed through the formation of a complex and free radical intermediate. The products were identified by spot test and characterized by spectral studies. The reaction constants involved in the different steps of the mechanism were calculated. The activation parameters with respect to slow step of the mechanism were computed and are discussed. The thermodynamic quantities were determined for different equilibrium steps. Isokinetic temperature was also calculated and found to be 252.3 K.

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Oxidative Cleavage of β-Lactam Ring of Cephalosporins with Chloramine-T in Alkaline Medium: A Kinetic, Mechanistic, and Reactivity Study

ISRN Physical Chemistry ◽

10.1155/2013/738932 ◽

2013 ◽

Vol 2013 ◽

pp. 1-10 ◽

Cited By ~ 4

Author(s):

Anu Sukhdev ◽

A. S. Manjunatha ◽

Puttaswamy Puttaswamy

Keyword(s):

Alkaline Medium ◽

Activation Parameters ◽

Oxidation Products ◽

Oxidation Reactions ◽

Mass Spectral ◽

Dielectric Effect ◽

Lactam Ring ◽

Chloramine T ◽

Reactivity Study ◽

Reaction Constants

Cephalosporins are β-lactam antibiotics, and the important drugs of this group are cephalexin, cefadroxil and cephradine. In the present research, the kinetics and mechanism of oxidation of cephalexin (CEX), cefadroxil (CFL), and cephradine (CPD) with chloramine-T (CAT) in alkaline medium were investigated at 301 K. All the three oxidation reactions follow identical kinetics with a first-order dependence each on [CAT]o and [substrate]o. The reaction is catalyzed by hydroxide ions, and the order is found to be fractional. The dielectric effect is negative. Proton inventory studies in H2O-D2O mixtures with CEX as a probe have been made. Activation parameters and reaction constants have been evaluated. Oxidation products were identified by mass spectral analysis. An isokinetic relation was observed with β = 378 K, indicating that enthalpy factors control the rate. The rate increases in the following order: CPD > CFL > CEX. The proposed mechanism and the derived rate law are consistent with the observed kinetics.

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Kinetics and Mechanistic Study of Permanganate Oxidation of Fluorenone Hydrazone in Alkaline Medium

Advances in Physical Chemistry ◽

10.1155/2016/4526578 ◽

2016 ◽

Vol 2016 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Ahmed Fawzy ◽

Saleh A. Ahmed ◽

Ismail I. Althagafi ◽

Moataz H. Morad ◽

Khalid S. Khairou

Keyword(s):

Ionic Strength ◽

Alkaline Medium ◽

Equilibrium Constants ◽

Activation Parameters ◽

Active Species ◽

Mechanistic Study ◽

Thermodynamic Quantities ◽

Rate Limiting Step ◽

Expression Rate ◽

Reaction Constants

The oxidation kinetics of fluorenone hydrazone (FH) using potassium permanganate in alkaline medium were measured at a constant ionic strength of 0.1 mol dm−3 and at 25°C using UV/VIS spectrophotometer. A first-order kinetics has been monitored in the reaction of FH with respect to [permanganate]. Less-than-unit order dependence of the reaction on [FH] and [OH−] was revealed. No pronounced effect on the reaction rate by increasing ionic strength was recorded. Intervention of free radicals was observed in the reaction. The reaction mechanism describing the kinetic results was illustrated which involves formation of 1 : 1 intermediate complex between fluorenone hydrazones and the active species of permanganate. 9H-Fluorenone as the corresponding ketone was found to be the final oxidation product of fluorenone hydrazone as confirmed by GC/MS analysis and FT-IR spectroscopy. The expression rate law for the oxidation reaction was deduced. The reaction constants and mechanism have been evaluated. The activation parameters associated with the rate-limiting step of the reaction, along with the thermodynamic quantities of the equilibrium constants, have been calculated and discussed.

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Mechanistic Aspects of Osmium(VIII) Catalyzed Oxidation of L-Tryptophan by Diperiodatocuprate(III) in Aqueous Alkaline Medium: A Kinetic Model

Research Letters in Inorganic Chemistry ◽

10.1155/2008/216058 ◽

2008 ◽

Vol 2008 ◽

pp. 1-5 ◽

Cited By ~ 2

Author(s):

Nagaraj P. Shetti ◽

Ragunatharaddi R. Hosamani ◽

Sharanappa T. Nandibewoor

Keyword(s):

Kinetic Model ◽

Alkaline Medium ◽

Active Species ◽

Probable Mechanism ◽

Spot Test ◽

Spectral Studies ◽

Aqueous Alkaline Medium ◽

Unit Order ◽

First Order ◽

Catalyzed Oxidation

In presence of osmium(VIII), the reaction between L-tryptophan and diperiodatocuprate(III) DPC in alkaline medium exhibits 1:4 stochiometry (L-tryptophan:DPC). The reaction shows first-order dependence on [DPC] and [osmium(VIII)], less than unit order in both [L-tryptophan] and [alkali], and negative fractional order in [periodate]. The active species of catalyst and oxidant have been identified. The main products were identified by spectral studies and spot test. The probable mechanism was proposed and discussed.

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Kinetic, Mechanistic, and Thermodynamic Studies for Oxidation of L-Alanine by Alkaline Sodium Periodate in Presence of Os(VIII) in its Nano Concentration Range as Homogenous Catalyst

BULLETIN OF CHEMICAL REACTION ENGINEERING AND CATALYSIS ◽

10.9767/bcrec.13.2.1583.355-364 ◽

2018 ◽

Vol 13 (2) ◽

pp. 355 ◽

Cited By ~ 1

Author(s):

Madhu Gupta ◽

Amrita Srivastava ◽

Sheila Srivastava

Keyword(s):

Sodium Periodate ◽

Activation Parameters ◽

Spectroscopic Studies ◽

Oxidation Products ◽

Slow Step ◽

Thermodynamic Quantities ◽

Thermodynamic Studies ◽

Negative Effect ◽

Reaction Constants ◽

Homogenous Catalyst

The kinetics and mechanism of homogenously Os(VIII) catalysed oxidation of L-alanine (L-ala) by alkaline sodium periodate in temperature range 30 to 45°C have been studied. The involvement of free radicals was observed in the reactions. The oxidation products were acetaldehyde and IO3-, identified by spot test and spectroscopic studies. The stoichiometry between [L-ala]: IO4- is 1:2. The reaction show negligible effect of mercuric acetate and ionic strength of medium. The experimental results show first order in oxidant [NaIO4] and negative effect of [OH-]. The order in [Os(VIII)] as well as L-alanine was unity. A mechanism involving the formation of complex between L-alanine and Os(VIII) was proposed. The reaction constants concerned in the different steps of mechanism were calculated at different temperature. The activation parameters for the slow step of mechanism were computed and discussed. The thermodynamic quantities were also calculated for the reaction. Copyright © 2018 BCREC Group. All rights reservedReceived: 11st October 2017; Revised: 11st February 2018; Accepted: 18th February 2018; Available online: 11st June 2018; Published regularly: 1st August 2018How to Cite: Gupta, M., Srivastava, A., Srivastava, S. (2018). Kinetic, Mechanistic, and Thermodynamic Studies for Oxidation of L-Alanine by Alkaline Sodium Periodate in Presence of Os(VIII) in its Nano Concentration Range as Homogenous Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (2): 355-364 (doi:10.9767/bcrec.13.2.1583.355-364)

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Kinetic and Mechanistic Aspects of Osmium(VIII) Catalyzed Oxidation of DL-ornithine by Copper(III) Periodate Complex in Aqueous Alkaline Medium

Zeitschrift für Physikalische Chemie ◽

10.1524/zpch.2010.5521 ◽

2010 ◽

Vol 224 (06) ◽

pp. 865-882 ◽

Cited By ~ 2

Author(s):

Jyothi C. Abbar ◽

Shweta J. Malode ◽

Sharanappa T. Nandibewoor

Keyword(s):

Alkaline Medium ◽

Activation Parameters ◽

Reaction Rates ◽

Oxidation Products ◽

Slow Step ◽

Thermodynamic Quantities ◽

Aqueous Alkaline Medium ◽

Uncatalyzed Reaction ◽

Different Temperatures ◽

Reaction Constants

AbstractThe oxidation of DL-ornithine monohydrochloride (OMH) by diperiodatocuprate(III) (DPC) has been investigated in the presence of osmium(VIII) catalyst in aqueous alkaline medium at a constant ionic strength of 0.20 mol dm−3 spectrophotometrically. The reaction exhibits 1:4 stoichiometry i.e., [OMH]: [DPC]. The order of the reaction with respect to [DPC] was unity while the order with respect to [OMH] was less than unity over the concentration range studied. The rate increased with an increase in [OH –] and decreased with an increase in [IO4−]. The order with respect to [Os(VIII)] was unity. The reaction rates revealed that Os(VIII) catalyzed reaction was about nine-fold faster than the uncatalyzed reaction. The oxidation products were identified by spectral analysis. Suitable mechanism has been proposed. The reaction constants involved in the different steps of the reaction mechanism were calculated. The catalytic constant (KC) was also calculated at different temperatures. The activation parameters with respect to slow step of the mechanism and also the thermodynamic quantities were determined. Kinetic experiments suggest that [OsO4(OH)2]2− is the reactive Os(VIII) species and [Cu(H2IO6)(H2O)2] is the reactive copper(III) species.

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Mechanistic investigations of oxidation of isatins by sodium N-chlorobenzenesulfonamide in alkaline medium: A kinetic study

Open Chemistry ◽

10.2478/bf02479277 ◽

2005 ◽

Vol 3 (3) ◽

pp. 482-501 ◽

Cited By ~ 6

Author(s):

◽

R. Jagadeesh

Keyword(s):

Alkaline Medium ◽

Reaction Times ◽

Activation Parameters ◽

Cost Effective ◽

Oxidation Products ◽

High Yield ◽

Rate Variation ◽

Isokinetic Relationship ◽

Anthranilic Acids ◽

Solvent Isotope

AbstractOxidation of isatins (isatin, 5-methylisatin, 5-bromoisatin and 5-nitroisatin) to their anthranilic acids was performed efficiently with sodium N-chlorobenzenesulfonamide or chloramine-B (CAB) in alkaline medium at 35±0.1°C. The reactions follow identical kinetics for all the isatins, being first-order dependence each in [CAB]o and [Isatin]o and inverse fractional-order on [NaOH]. Addition of halide ions and benzenesulfonamide, reduction product of CAB, do not significantly affect the rate. Variation of ionic strength of the medium had no effect on the rate, while the dielectric effect is negative. The solvent isotope effect was studied using D2O. Activation parameters for the overall reaction have been computed. The rates satisfactorily correlate with the Hammett σ relationship and the reaction constant ρ is −0.31 signifies that electron releasing groups accelerate the reaction while the electron withdrawing groups retard the rate. Values of ΔH≠ and ΔS≠ are linearly related and an isokinetic relationship is observed with β=376 K, indicating the reaction is controlled by enthalpy. The stoichiometry of the title reaction is found to be 1∶1. Oxidation products of isatins were identified as their corresponding anthranilic acids and the yields were found to be around 90 %. The observed results have been explained by a plausible mechanism and the related rate law deduced. This method offers several advantages including high yield of the products, short reaction times, easier isolation of products, and stable, cost effective and relatively non-toxic reagents, which make the reaction process simple and smooth.

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Quantum chemical insight into molecular structure, spectroscopic and nonlinear optical studies on methylene bis(dithiobenzoate)-=SUP=-*-=/SUP=-

Оптика и спектроскопия ◽

10.21883/os.2021.09.51338.1060-21 ◽

2021 ◽

Vol 129 (9) ◽

pp. 1136

Author(s):

Davut Avci ◽

Semiha Bahceli

Keyword(s):

Title Compound ◽

Quantum Chemical ◽

Density Functional ◽

Nonlinear Optical ◽

Chemical Shifts ◽

Basis Set ◽

Spectral Studies ◽

Nmr Chemical Shifts ◽

Vis Spectroscopy ◽

C Nmr

In this study, the methylene bis(dithiobenzoate) molecule, (C15H12S4), as a bioactive molecule has been subjected to quantum chemical computations using density functional theory (DFT) in order to investigate the molecular geometry, IR, UV-visible and NMR spectral studies. The title molecule has been optimized at the B3LYP, B3PW91 and PBE11PBE levels of DFT and 6-311G(d,p) basis set. Furthermore, the vibrational frequencies, the HOMO-LUMO energy levels, the 1H and 13C NMR chemical shifts (ppm), nonlinear optical properties calculations of the title compound were obtained by B3LYP, B3PW91 and PBE1PBE levels. The maximum electronic transition wavelengths, oscillator strengths, excited state and transition dipole moments for the title compound were also investigated by B3LYP, B3PW91 and PBE1PBE levels of time-dependent (TD)-DFT. Keywords: methylene bis(dithiobenzonoate), IR and UV-vis spectroscopy, 1H and 13C NMR chemical shifts, NLO DFT method.

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Kinetics and mechanism of the oxidation of polyhydric alcohols by dihydroxyditelluratoargentate(III) in alkaline medium

Journal of the Serbian Chemical Society ◽

10.2298/jsc0504592s ◽

2005 ◽

Vol 70 (4) ◽

pp. 585-592 ◽

Cited By ~ 4

Author(s):

J.H. Shan ◽

S.Y. Huo ◽

S.G. Shen ◽

H.W. Sun

Keyword(s):

Alkaline Medium ◽

Activation Parameters ◽

Order Rate Constant ◽

Active Species ◽

Rate Equations ◽

Kinetics Of Oxidation ◽

First Order ◽

Rate Determining Step ◽

Plausible Mechanism ◽

Kinetics Of

The kinetics of oxidation of 1,2-propanediol and 1,2,3-propanetriol by dihydroxyditelluratoargentate(III) (DDA) were studied spectrophotometrically between 298.2 K and 313.2 K in alkaline medium. The reaction rate showed first order dependence on DDA and 1 < nap < 2 order on the reductant. It was found that the pseudo-first order rate constant kobs increased with increasing concentration of OH-1 and decreasing concentration of TeO42-. There is a negative salt effect and no free radicals were detected. In view of this, the dihydroxymonotelluratoargentate(III) species is assumed to be the active species. A plausible mechanism involving a two-electron transfer is proposed and the rate equations derived from the mechanism can explain all the experimental results. The activation parameters, as well as the rate constants of the rate-determining step were calculated.

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Formation of active species from ruthenium alkylidene catalysts—an insight from computational perspective

Journal of Molecular Modeling ◽

10.1007/s00894-019-4202-5 ◽

2019 ◽

Vol 25 (11) ◽

Author(s):

Paweł Śliwa ◽

Mariusz P. Mitoraj ◽

Filip Sagan ◽

Jarosław Handzlik

Keyword(s):

Transition State ◽

Density Functional ◽

Activation Parameters ◽

Decomposition Methods ◽

Active Species ◽

Basis Set ◽

Activation Process ◽

Orbital Interaction ◽

Basis Set Superposition Error ◽

London Dispersion

Abstract Ruthenium alkylidene complexes are commonly used as olefin metathesis catalysts. Initiation of the catalytic process requires formation of a 14-electron active ruthenium species via dissociation of a respective ligand. In the present work, this initiation step has been computationally studied for the Grubbs-type catalysts (H2IMes)(PCy3)(Cl)2Ru=CHPh, (H2IMes)(PCy3)(Cl)2Ru=CH-CH=CMe2 and (H2IMes)(3-Br-py)2(Cl)2Ru=CHPh, and the Hoveyda-Grubbs-type catalysts (H2IMes)(Cl)2Ru=CH(o-OiPrC6H4), (H2IMes)(Cl)2Ru=CH(5-NO2–2-OiPrC6H3), and (H2IMes)(Cl)2Ru=CH(2-OiPr-3-PhC6H3), using density functional theory (DFT). Additionally, the extended-transition-state combined with the natural orbitals for the chemical valence (ETS-NOCV) and the interacting quantum atoms (IQA) energy decomposition methods were applied. The computationally determined activity order within both families of the catalysts and the activation parameters are in agreement with reported experimental data. The significance of solvent simulation and the basis set superposition error (BSSE) correction is discussed. ETS-NOCV demonstrates that the bond between the dissociating ligand and the Ru-based fragment is largely ionic followed by the charge delocalizations: σ(Ru–P) and π(Ru–P) and the secondary CH…Cl, CH…π, and CH…HC interactions. In the case of transition state structures, the majority of stabilization stems from London dispersion forces exerted by the efficient CH…Cl, CH…π, and CH…HC interactions. Interestingly, the height of the electronic dissociation barriers is, however, directly connected with the prevalent (unfavourable) changes in the electrostatic and orbital interaction contributions despite the favourable relief in Pauli repulsion and geometry reorganization terms during the activation process. According to the IQA results, the isopropoxy group in the Hoveyda-Grubbs-type catalysts is an efficient donor of intra-molecular interactions which are important for the activity of these catalysts.

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