Kinetics of acid-catalysed hydrolysis of the α and β Carbonato(4,7-dimethyltriethylenetetramine) cobalt(III) ions

1974 ◽  
Vol 27 (2) ◽  
pp. 269 ◽  
Author(s):  
DJ Francis ◽  
GH Searle
Keyword(s):  
Acid Hydrolysis ◽  
Perchloric Acid ◽  
Rate Constants ◽  
Dissociation Constants ◽  
Bond Cleavage ◽  
Acid Dissociation ◽  
Acid Dissociation Constants ◽  
Rate Laws ◽  
Kinetics Of ◽  
Hydrolysis Of

The synthesis and separation of the complexes α-[Co(dmtr)CO3] ClO4 and β-[Co(dmtr)CO3] C1O4,H2O (dmtr = 4,7-dimethyltriethylenetetramine or N,N'-bis(2-aminoethyl)-N,N'-dimethylethane-1,2-diamine) are described. The kinetics of the acid hydrolysis of both complexes, studied in perchloric acid at 25�C and μ = 1.0M (LiC1O4), follow rate laws of form -d[complex]dt=(k0 + k1[H+I)[complex] The values of ko and k1 for the K-complex are 1.0 x 10-3 s-1 and 1.8 x 10-2 1. mol-1 s-1 respectively, while for the β-complex the corresponding values are 3.6 x 10-5 s-1 and 5.6 x 10-4 1. mol-1 s-1. Comparisons of these rate constants with the values for similar carbonato(tetramine)cobalt(111) complexes previously studied suggest that the ko path could involve O-C bond cleavage in the present dmtr complexes. The values of the acid dissociation constants of dmtr,4HCl, determined by potentiometric titration, are 1.61, 5.86, 8.18 and 9.95.

The comparative chemistry of ammine and methylamine complexes of rhodium(III) and cobalt(III)

1977 ◽  
Vol 55 (17) ◽  
pp. 3166-3171 ◽  
Author(s):  
Thomas Wilson Swaddle
Keyword(s):  
Ionic Strength ◽  
Spectral Data ◽  
Electron Donor ◽  
Dissociation Constants ◽  
Base Hydrolysis ◽  
Acid Dissociation ◽  
Rate Coefficients ◽  
Acid Dissociation Constants ◽  
First Order ◽  
Kinetics Of

For the aquation of (CH3NH2)5RhCl2+, the first order rate coefficients are represented by ΔHaq* = 101.9 kJ mol−1 and ΔSaq* = −50.2 JK−1 mol−1 in 0.1 M HClO4, while for base hydrolysis the rate is first order in [(CH3NH2)5RhCl2+] and [OH−] at ionic strength 0.10 M and the rate coefficients (in M−1 s−1) are represented by ΔHOH*> = 108.6 kJ mol−1 and ΔSOH* = 74.1 J K−1 mol−1. Acid dissociation constants are reported for (RNH2)5MOH23+ (R = H or CH3; M = Rh or Co), and these, combined with spectral data, show CH3NH2 to be a poorer electron donor than NH3 in complexes of this type, contrary to expectations. The comparative kinetics of reactions of (RNH2)5MCl2+ support the assignment of an Ia mechanism to aquation when M = Rh or Cr, Id to aquation when M = Co, and Dcb for base hydrolysis in all these cases.

Acid Dissociation Constants and Saponification Rate Constants for Some 1-Naphthoic and Thenoic Acid Derivatives

1954 ◽  
Vol 76 (20) ◽  
pp. 5131-5132 ◽  
Author(s):  
Charles C. Price ◽  
Edwin C. Mertz ◽  
John Wilson
Keyword(s):  
Rate Constants ◽  
Dissociation Constants ◽  
Acid Dissociation ◽  
Acid Dissociation Constants

Studies on Lactoperoxidase. VI. Kinetics of the Oxidation of p-Cresol by Compound II

1973 ◽  
Vol 51 (11) ◽  
pp. 1721-1723 ◽  
Author(s):  
R. James Maguire ◽  
H. Brian Dunford
Keyword(s):  
Dissociation Constants ◽  
Acid Dissociation ◽  
Stopped Flow ◽  
Acid Dissociation Constants ◽  
First Order ◽  
Diffusion Controlled ◽  
Ph Range ◽  
Rate Profile ◽  
Compound Ii ◽  
Kinetics Of

The kinetics of the oxidation of p-cresol by compound II of lactoperoxidase have been studied over the pH range 2.1–11.2 by the stopped-flow technique. The reaction is kinetically first-order with respect to p-cresol over the entire pH range. Use is made of the diffusion-controlled limit that can be placed on a bimolecular rate constant to show that p-cresol reacts in the unionized form. The complexity of the pH-rate profile is discussed in terms of acid dissociation constants of groups in the enzyme and the ionization of the substrate.

scholarly journals The Kinetics of Chitosan Degradation in Organic Acid Solutions

Marine Drugs ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. 236
Author(s):  
Dominik Sikorski ◽  
Karolina Gzyra-Jagieła ◽  
Zbigniew Draczyński
Keyword(s):  
Organic Acid ◽  
Dissociation Constants ◽  
Degradation Process ◽  
Acid Dissociation ◽  
Acid Solutions ◽  
Spectroscopy Analysis ◽  
Acid Dissociation Constants ◽  
Spinning Process ◽  
Kinetics Of ◽  
Selection Of

This paper presents a comparative study on chitosan degradation in organic acid solutions according to their different dissociation characteristics. More precisely, the aim of the study was to determine the kinetics of the degradation process depending on the different acid dissociation constants (pKa values). The scientists involved in chitosan to date have focused mainly on acetic acid solutions. Solutions of lactic, acetic, malic, and formic acids in concentrations of 3% wt. were used in this research. The progress of degradation was determined based on the intrinsic viscosity measurement, GPC/SEC chromatographic analysis, and their correlation. Changes in the viscosity parameters were performed at a temperature of 20 °C ± 1 °C and a timeframe of up to 168 h (7 days). The chemical structure and DDA of the initial chitosan were analyzed using 1H-NMR spectroscopy analysis. The results of this study can be considered of high importance for the purpose of electrospinning, production of micro- and nano-capsules for drug delivery, and other types of processing. Understanding the influence of the dissociation constant of the solvent on the kinetics of chitosan degradation will allow the selection of an appropriate medium, ensuring an effective and stable spinning process, in which the occurrence of polymer degradation is unfavorable.

Kinetics of hydrolysis of peroxodisulphate ions in acidic medium to peroxomonosulphuric acid

1981 ◽  
Vol 46 (5) ◽  
pp. 1229-1236 ◽  
Author(s):  
Jan Balej ◽  
Milada Thumová
Keyword(s):  
Ionic Strength ◽  
Rate Constants ◽  
Acidic Medium ◽  
Measured Data ◽  
Molar Ratios ◽  
Starting Solution ◽  
Kinetics Of Hydrolysis ◽  
Rate Of Hydrolysis ◽  
Kinetics Of ◽  
Hydrolysis Of

The rate of hydrolysis of S2O82- ions in acidic medium to peroxomonosulphuric acid was measured at 20 and 30 °C. The composition of the starting solution corresponded to the anolyte flowing out from an electrolyser for production of this acid or its ammonium salt at various degrees of conversion and starting molar ratios of sulphuric acid to ammonium sulphate. The measured data served to calculate the rate constants at both temperatures on the basis of the earlier proposed mechanism of the hydrolysis, and their dependence on the ionic strength was studied.

Analyses of the Acid Dissociation Constants of Multisubstituted Diarylamines Measured in Solvents and Micellar System

1994 ◽  
Vol 67 (3) ◽  
pp. 800-806 ◽  
Author(s):  
Ze-jian Guo ◽  
Hideto Miyoshi ◽  
Toshio Fujita
Keyword(s):  
Dissociation Constants ◽  
Acid Dissociation ◽  
Micellar System ◽  
Acid Dissociation Constants

ChemInform Abstract: Determination of the Acid Dissociation Constants for Some Mycotoxins of the Alternaria alternata genus.

ChemInform ◽  
2010 ◽  
Vol 29 (52) ◽  
pp. no-no
Author(s):  
P. G. MOLINA ◽  
M. A. ZON ◽  
H. FERNANDEZ
Keyword(s):  
Alternaria Alternata ◽  
Dissociation Constants ◽  
Acid Dissociation ◽  
Acid Dissociation Constants
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