Kinetics of metal ion and metal chelate catalyzed oxidation of ascorbic acid. III. Vanadyl ion catalyzed oxidation

1968 ◽  
Vol 90 (22) ◽  
pp. 6011-6017 ◽  
Author(s):  
M. M. Taqui. Khan ◽  
A. E. Martell
Keyword(s):  
Ascorbic Acid ◽  
Metal Ion ◽  
Metal Chelate ◽  
Vanadyl Ion ◽  
Kinetics Of ◽  
Catalyzed Oxidation

scholarly journals Kinetics and Mechanism of Catalyzed Oxidation of L-Cysteine by Salen Schiff Base Complexes of Co(III), Fe (III) and Cr(III)

2021 ◽  
Vol 13 (2) ◽  
pp. 25
Author(s):  
Hamzeh M. Abdel-Halim ◽  
Hutaf M. Baker ◽  
Akef I. Alhmaideen ◽  
Adnan S. Abu-Surrah
Keyword(s):  
Schiff Base ◽  
Metal Ion ◽  
Reduction Potential ◽  
Order Conditions ◽  
Schiff Base Complexes ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
Constant Ph ◽  
Kinetics Of ◽  
Catalyzed Oxidation

Kinetics of oxidation of L-cysteine by new series of substituted ONNO-donor salen-type Schiff base complexes of general formula [MIII(L)Cl] (M = Co, Fe, Cr; L = Schiff base ligand) have been studied in aqueous solutions. Measurements were run at constant temperature (25º C), constant ionic strength (0.20 M), and constant pH (7.0) under pseudo-first order conditions, in which the concentration of cysteine is around two orders of magnitude greater than that of metal complex. The observed rate constant was determined by following the change in absorbance of reaction mixture at a predetermined wavelength with time. Results show that the rate of oxidation depends on the type of metal center, with Co(III) complexes were found to have the highest rates due to higher reduction potential of Co(III). The oxidation rate was also found to depend on steric factor and the electron withdrawing / releasing ability of the ligand bound to the metal ion.

Kinetics and mechanism of the reaction of iron(III) with 6-methyl-2,4-heptanedione and 3,5-heptanedione

1990 ◽  
Vol 55 (8) ◽  
pp. 1984-1990 ◽  
Author(s):  
José M. Hernando ◽  
Olimpio Montero ◽  
Carlos Blanco
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Activation Parameters ◽  
Enol Form ◽  
Kinetics And Mechanism ◽  
Kinetic Constants ◽  
Steric Factors ◽  
Kinetics Of ◽  
Mechanism Of The Reaction

The kinetics of the reactions of iron(III) with 6-methyl-2,4-heptanedione and 3,5-heptanedione to form the corresponding monocomplexes have been studied spectrophotometrically in the range 5 °C to 16 °C at I 25 mol l-1 in aqueous solution. In the proposed mechanism for the two complexes, the enol form reacts with the metal ion by parallel acid-independent and inverse-acid paths. The kinetic constants for both pathways have been calculated at five temperatures. Activation parameters have also been calculated. The results are consistent with an associative activation for Fe(H2O)63+ and dissociative activation for Fe(H2O)5(OH)2+. The differences in the results for the complexes of heptanediones studied are interpreted in terms of steric factors.

Ambivalent role of ascorbic acid in the metal-catalyzed oxidation of oligopeptides

2021 ◽  
pp. 111510
Author(s):  
Nikolett Bodnár ◽  
Katalin Várnagy ◽  
Lajos Nagy ◽  
Gizella Csire ◽  
Csilla Kállay
Keyword(s):  
Ascorbic Acid ◽  
Metal Catalyzed Oxidation ◽  
Metal Catalyzed ◽  
Catalyzed Oxidation

Synthesis and evaluation of the influence of 5-sulfanyl-1,2,3-triazol-1-ylaminocarboxylic acid derivatives on kinetics of ascorbic acid oxidation

2016 ◽  
Vol 65 (1) ◽  
pp. 203-208 ◽  
Author(s):  
V. V. Emelianov ◽  
A. V. Musalnikova ◽  
E. A. Savateeva ◽  
Yu. S. Shakhmina ◽  
T. A. Kalinina ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Acid Oxidation ◽  
Kinetics Of
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