Kinetics of oxidation of bis(ethylenediamine)mercaptoacetatocobalt(III) and cysteinatobis(ethylenediamine)cobalt(III) ions by peroxodisulphate in aqueous-nonaqueous mixed solvents

1986 ◽  
Vol 51 (5) ◽  
pp. 1049-1060 ◽  
Author(s):  
Oľga Vollárová ◽  
Ján Benko ◽  
Ivana Matejeková
Keyword(s):  
Perchloric Acid ◽  
Transfer Functions ◽  
Mixed Solvents ◽  
Sodium Perchlorate ◽  
Activation Parameters ◽  
Solvent System ◽  
Butyl Alcohol ◽  
Complex Ions ◽  
Kinetics Of Oxidation ◽  
Kinetics Of

The kinetics of oxidation in the first step was studied for coordination-bonded sulphur in the cysteinatobis(ethylenediamine)cobalt(III) and bis(ethylenediamine)mercaptoacetatocobalt(III) ions using peroxodisulphate as oxidant. The effect of the acid-base equilibria of the reactants was established based on the dependences of the rate constant and the thermodynamic activation parameters ΔH and ΔS on perchloric acid concentration. The effect of ionic strength at various perchloric acid concentrations, was examined for the two complex ions. The combined effect of perchloric acid and sodium perchlorate was investigated in water-tert-butyl alcohol and water-ethylene glycol solutions. The transfer functions were calculated from the changes in the solubility of the reactants on passing from aqueous to the mixed aqueous-nonaqueous solutions, and the role of solvation during the oxidation of the complexes by peroxodisulphate was assessed based on the dependences of the transfer functions on the nonaqueous component content of the solvent system.

Thermodynamic and Kinetic Investigation of the Solvent Effect on the Oxidation of [Co(en)2SCH2COO]+ with S2O82- In Water-Methanol and Water-tert-Butyl Alcohol Mixtures

1993 ◽  
Vol 58 (5) ◽  
pp. 1001-1006 ◽  
Author(s):  
Oľga Vollárová ◽  
Ján Benko
Keyword(s):  
Transfer Functions ◽  
Activation Parameters ◽  
Butyl Alcohol ◽  
Oxidation Of Co ◽  
Kinetics Of Oxidation ◽  
Tert Butyl ◽  
Tert Butyl Alcohol ◽  
Alcohol Mixtures ◽  
Kinetics Of

The kinetics of oxidation of [Co(en)2SCH2COO]+ with S2O82- was studied in water-methanol and water-tert-butyl alcohol mixtures. Changes in the reaction activation parameters ∆H≠ and ∆S≠ with varying concentration of the co-solvent depend on the kind of the latter, which points to a significant role of salvation effects. The solvation effect on the reaction is discussed based on a comparison of the transfer functions ∆Ht0, ∆St0 and ∆Gt0 for the initial and transition states with the changes in the activation parameters accompanying changes in the CO-solvent concentration. The transfer enthalpies of the reactant were obtained from calorimetric measurements.

A KINETICS AND MECHANISTIC STUDY OF THE OXIDATION OF L-ARGININE BY QDC IN DMF-WATER MEDIUM

2021 ◽  
pp. 11-12
Author(s):  
Deepika Jain ◽  
Shilpa Rathor
Keyword(s):  
Perchloric Acid ◽  
Reaction Rate ◽  
Main Product ◽  
Activation Parameters ◽  
Reaction Rates ◽  
Mechanistic Study ◽  
Water Medium ◽  
Volume Percentage ◽  
Kinetics Of Oxidation ◽  
Kinetics Of

The present paper describes the kinetics of oxidation of l-Arginine by QDC in the presence of perchloric acid in 30% DMF-H O(v/v) medium at 2 + 40⁰C spectrophotometrically at λ =354nm. The reaction is rst order with respect to [QDC], [H ], and [substrate]. The reaction rate increased with max increasing volume percentage of DMF in reaction mixture. Michaelis- Menten type kinetic was observed with l-Arginine. The reaction rates were studied at different temperature and the activation parameters has been computed. The main product was identied as Cr (III) and 4-Guanidino buteraldehyde.

Kinetics of oxidation of the bis(ethylenediamine)mercaptoacetatocobalt(III) and cysteinato-bis(ethylenediamine)cobalt(III) ions by hydrogen peroxide in mixed aqueous-nonaqueous solutions

1988 ◽  
Vol 53 (3) ◽  
pp. 554-562
Author(s):  
Ján Benko ◽  
Oľga Vollárová ◽  
Miroslav Kovarčík
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Rate ◽  
Activation Parameters ◽  
Butyl Alcohol ◽  
Acid Base ◽  
Kinetics Of Oxidation ◽  
Tert Butyl Alcohol ◽  
Alcohol Water ◽  
Acid Base Equilibrium ◽  
Kinetics Of

The kinetics of oxidation of the coordinatively bonded sulphur in the cysteinato-bis(ethylenediamine)cobalt(III) and bis(ethylenediamine)mercaptoacetatocobalt(III) complexes by hydrogen peroxide to the sulphoxides was examined in HClO4 solutions (c(HClO4) = 1 – 500 mmol l-1) with a view to obtaining data characterizing the effect of the acid-base equilibria of the reactants on the reaction rate. The reaction rate was found affected particularly by the acid-base equilibrium of the oxidant, which plays a role in strongly acid solutions. The oxidation was also studied in water-methyl alcohol, water-tert-butyl alcohol and water-ethylene glycol mixtures, and the effect of the mole fraction of the nonaqueous component on the rate constant and thermodynamic activation parameters was examined.

scholarly journals Kinetics and Mechanism of Oxidation of Isoleucine byN-Bromophthalimide in Aqueous Perchloric Acid Medium

2011 ◽  
Vol 8 (4) ◽  
pp. 1728-1733 ◽  
Author(s):  
N. M. I. Alhaji ◽  
S. Sofiya Lawrence Mary
Keyword(s):  
Acid Medium ◽  
Perchloric Acid ◽  
Reaction Rate ◽  
Activation Parameters ◽  
Halide Ions ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
Hypobromous Acid ◽  
Different Temperatures ◽  
Kinetics Of

The kinetics of oxidation of isoleucine withN-bromophthalimide has been studied in perchloric acid medium potentiometrically. The reaction is of first order each in [NBP] and [amino acid] and negative fractional order in [H+]. The rate is decreased by the addition of phthalimide. A decrease in the dielectric constant of the medium increases the rate. Addition of halide ions or acrylonitrile has no effect on the kinetics. Similarly, variation of ionic strength of the medium does not affect the reaction rate. The reaction rate has been determined at different temperatures and activation parameters have been calculated. A suitable mechanism involving hypobromous acid as reactive species has been proposed.

Kinetics of alkaline hydrolysis of 3,4-thiophenedicarboxylic acid monomethyl ester in aqueous-nonaqueous media

1988 ◽  
Vol 53 (6) ◽  
pp. 1268-1273
Author(s):  
Ján Benko ◽  
Oľga Vollárová
Keyword(s):  
Methyl Alcohol ◽  
Alkaline Hydrolysis ◽  
Mixed Solvents ◽  
Activation Parameters ◽  
Butyl Alcohol ◽  
Nonaqueous Media ◽  
Alcohol Water ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Monomethyl Ester

The kinetics of alkaline hydrolysis of 3,4-thiophenedicarboxylic acid monomethyl ester has been studied in mixed solvents water-methyl alcohol, water-tert-butyl alcohol, and water-dioxane. The specific effects causing different courses of these dependences have been evaluated. The greatest changes in the thermodynamic activation parameters have been observed in the medium of water-methyl alcohol.

Solvolysis rates in aqueous–organic mixed solvents. III. Kinetics of the alkaline solvolysis of monochloroacetate ion in water – tert-butyl alcohol solutions

1976 ◽  
Vol 54 (11) ◽  
pp. 1687-1691 ◽  
Author(s):  
El-Hussieny M. Diefallah
Keyword(s):  
Mole Fraction ◽  
Mixed Solvents ◽  
Activation Parameters ◽  
Butyl Alcohol ◽  
Solvent Mixtures ◽  
First Order ◽  
Tert Butyl Alcohol ◽  
Rate Of Reaction ◽  
Aqueous Organic Mixed Solvents ◽  
Kinetics Of

The temperature dependence of the rate of alkaline solvolysis of monochloroacetate ion in water – tert-bulyl alcohol solutions has been determined. The rates of reaction were first order with respect to both the chloroacetate ion and to the total solvoxide ion concentrations. The reactivity is enhanced, first slowly, and then more rapidly, by increasing the concentration of tert-bulyl alcohol in the solvent mixtures. The rate of reaction increases with the reciprocal of the dielectric constant of the medium and the plot of log kvs. 1/D can best be represented by two lines intersecting at a point corresponding to 0.9 water mole fraction. The activation parameters ΔH*and ΔS* for the solvolysis reaction showed a minimum at about 0.9 water mole fraction. The significance of these results from the viewpoint of the electrostatic theory and the changing of solvent structure in such mixtures is discussed.

scholarly journals Kinetics and Mechanism of Oxidation of Benzyl Alcohol by Benzimidazolium Fluorochromate

2008 ◽  
Vol 5 (4) ◽  
pp. 754-760
Author(s):  
J. Dharmaraja ◽  
K. Krishnasamy ◽  
M. Shanmugam
Keyword(s):  
Benzyl Alcohol ◽  
Sodium Perchlorate ◽  
Activation Parameters ◽  
Aqueous Acetic Acid ◽  
Hydrogen Ions ◽  
Acetic Acid Medium ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
Oxidation Of Benzyl Alcohol ◽  
Kinetics Of

The kinetics of oxidation of benzyl alcohol (BzOH) by benzimidazolium fluorochromate (BIFC) has been studied in 50% aqueous acetic acid medium at 308 K. The reaction is first order with respect to [oxidant] and [benzyl alcohol]. The reaction is catalysed by hydrogen ions. The decrease in dielectric constant of the medium increases the rate of the reaction. Addition of sodium perchlorate increases the rate of the reaction appreciably. No polymerization with acrylonitrile. The reaction has been conducted at four different temperature and the activation parameters were calculated. From the observed kinetic results a suitable mechanism was proposed.

scholarly journals Oxidation of α,β-Unsaturated Alcohols by Quinaldinium Fluorochromate

2013 ◽  
Vol 5 ◽  
pp. 8-19
Author(s):  
Guna Sekar Krishnamoorthy ◽  
Seplapatty Kalimuthu Periyasamy
Keyword(s):  
Allyl Alcohol ◽  
Sodium Perchlorate ◽  
Activation Parameters ◽  
Cinnamyl Alcohol ◽  
Kinetics Of Oxidation ◽  
Unsaturated Alcohols ◽  
Crotyl Alcohol ◽  
Different Temperatures ◽  
Kinetics Of ◽  
Reactivity Order

The kinetics of oxidation of α,β-unsaturated alcohols (allyl alcohol, Crotyl alcohol, Cinnamyl alcohol) by quinaldinium fluorochromate has been studied in aqueous acid medium at 313 K. α,β-unsaturated alcohols were converted to the corresponding acrolein, crotonaldehyde and cinnamaldehyde. The reaction is first order each in oxidant, substrate and H+. The decrease in dielectric constant of the medium increases the rate of the reaction. Increase in ionic strength by the addition of sodium perchlorate has no effect on the rate constant. There is no polymerization with acrylonitrile. The reaction has been conducted at four different temperatures and activation parameters were calculated. From the observed kinetic results a suitable mechanism consistent with rate law has been proposed. The relative reactivity order was found to be Cinnamyl alcohol > Crotyl alcohol > Allyl alcohol.

Kinetics and Mechanism of Hexachloroiridate(IV) Oxidation of Arsenic(III) in Acidic Perchlorate Solutions

1992 ◽  
Vol 57 (7) ◽  
pp. 1451-1458 ◽  
Author(s):  
Refat M. Hassan
Keyword(s):  
Ionic Strength ◽  
Fractional Order ◽  
Activation Parameters ◽  
Order Reaction ◽  
First Order Reaction ◽  
Intermediate Complex ◽  
Constant Ionic Strength ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
Kinetics Of

The kinetics of oxidation of arsenic(III) by hexachloroiridate(IV) at lower acid concentrations and at constant ionic strength of 1.0 mol dm-3 have been investigated spectrophotometrically. A first-order reaction in [IrCl62-] and fractional order with respect to arsenic(III) have been observed. A kinetic evidence for the formation of an intermediate complex between the hydrolyzed arsenic(III) species and the oxidant was presented. The results showed that decreasing the [H+] is accompanied by an appreciable acceleration of the rate of oxidation. The activation parameters have been evaluated and a mechanism consistent with the kinetic results was suggested.

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