Medium effects on activation parameters on alkaline hydrolysis of 2-carbomethoxypropionate ion in aqueous mixtures of ethylene glycol

1987 ◽  
Vol 65 (2) ◽  
pp. 235-237 ◽  
Author(s):  
Prasanta Kumar Biswas ◽  
Bikas Chandra Bag ◽  
Mihir Nath Das
Keyword(s):  
Ethylene Glycol ◽  
Alkaline Hydrolysis ◽  
Silver Salt ◽  
Activation Parameters ◽  
Aqueous Mixtures ◽  
Free Energies ◽  
Medium Effects ◽  
Transfer Parameters ◽  
Experimental Values ◽  
Hydrolysis Of

The standard free energies of transfer [Formula: see text] of the 2-carbomethoxypropionate ion (R−) have been determined from the solubilities of the silver salt (AgR) in water and six aqueous mixtures of ethylene glycol (1–60%) at 25 °C, using the literature values of [Formula: see text] of Ag+. Utilizing these values of the R− ion as well as the literature values of [Formula: see text] of the OH− ion, combined with the experimental values of ΔG≠ for the alkaline hydrolysis of R− ion, the corresponding transfer parameters of the transition states [Formula: see text] for the hydrolysis reaction in aquo-glycolic media at 25 °C have been calculated. Attempts have been made to correlate the rates and activation parameters with the transfer quantities and solvent properties.

scholarly journals Effect of Cationic/Anionic Mixed Micelles on Reaction Kinetics of Alkaline Hydrolysis of Crystal Violet

2019 ◽  
Vol 31 (3) ◽  
pp. 651-655
Author(s):  
Qidist Yilma ◽  
Dunkana Negussa ◽  
Y. Dominic Ravichandran
Keyword(s):  
Crystal Violet ◽  
Alkaline Hydrolysis ◽  
Mixed Micelles ◽  
Sodium Dodecyl ◽  
Binding Constants ◽  
Regression Parameters ◽  
Experimental Values ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Good Agreement

Kinetics of alkaline hydrolysis of crystal violet, a triphenylmethane dye in the micellar environment of cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfonate (SDS) and binary mixtures of these surfactants was studied. The regression parameters, together with rate constants and binding constants were obtained by analyzing the rate surfactant profiles using cooperativity model. It was observed that the reaction was catalyzed by both surfactants. The catalytic factor increased by 10 times in SDS and 38 times in CTAB indicating that binding of crystal violet to the micellar surface is stronger in pure CTAB than SDS but the strength drastically reduced in the mixtures of the surfactants. Reduction of binding constant became more important as the mole fraction of CTAB was improved in the mixture. The kinetic data were investigated using Piszkiewicz model and Raghavan-Srinivasan model. The data obtained from the models were in good agreement with the experimental values.

Effects of Molecular Weight of Poly(ethylene glycol) on the Thermal Properties and the Alkaline Hydrolysis of Copolyesters

2012 ◽  
Vol 49 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Young-June Kim ◽  
Min-Ho Jee ◽  
Eun-Hee Lee ◽  
Jin-Uk Choi ◽  
Dong-Hyun Noh ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Thermal Properties ◽  
Ethylene Glycol ◽  
Alkaline Hydrolysis ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene ◽  
Hydrolysis Of

Effect of the α- and γ-Hydroxyls on the Alkaline Hydrolysis Rate of Nonphenolic β-0-4 Lignin Diastereomers

Holzforschung ◽  
2002 ◽  
Vol 56 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Dexter L. Criss ◽  
Thomas Elder ◽  
Thomas H. Fisher ◽  
Tor P. Schultz
Keyword(s):  
Computational Modeling ◽  
Alkaline Hydrolysis ◽  
Rate Ratio ◽  
Electronic Effect ◽  
Activation Parameters ◽  
Hydrolysis Rate ◽  
Significant Extent ◽  
Hydrolysis Rates ◽  
Lignin Model ◽  
Hydrolysis Of

Summary Nonphenolic β-0-4 erythro and threo lignin model diastereomers with various γ-groups (CH3, CH2-O-CH3, and CH2OH) and Cα-substituents (OH, OCH3) were synthesized, and the alkaline hydrolysis rates and activation parameters determined. In addition, two of the diastereomer pairs were computationally modeled and the thermodynamic values for the ionization of the α- or γ-hydroxyl, and subsequent displacement of the phenolate group to form an epoxide intermediate, were determined. The results suggest that the erythro γ-hydroxyl may participate in the hydrolysis to a significant extent, which results in a relatively high erythro/threo rate ratio for the α,γ-di-OH isomers. The influence of the erythro γ-hydroxyl on the hydrolysis rate may be due to the relatively favorable stability of the erythro γ-oxyanion. The electronic effect of the g-substituent appears to influence how fast the α-hydroxyl displaces the phenoxyl. We had previously suggested that the γ-substituent sterically inhibits hydrolysis of the threo isomer, and computational modeling confirmed this.

Medium effects in the acid catalyzed hydrolysis of benzohydroxamic acid in binary aqueous mixtures

1993 ◽  
Vol 49 (2) ◽  
pp. 403-409 ◽  
Author(s):  
Kallol K. Ghosh ◽  
Kishor K. Krishnani
Keyword(s):  
Aqueous Mixtures ◽  
Medium Effects ◽  
Benzohydroxamic Acid ◽  
Acid Catalyzed ◽  
Hydrolysis Of

Medium effect on alkaline hydrolysis of diphenic acid monomethyl ester

1980 ◽  
Vol 45 (5) ◽  
pp. 1485-1494 ◽  
Author(s):  
Ján Benko ◽  
Vladislav Holba
Keyword(s):  
Alkaline Hydrolysis ◽  
Reaction Medium ◽  
Activation Parameters ◽  
Butyl Alcohol ◽  
Medium Effect ◽  
Tert Butyl Alcohol ◽  
Diphenic Acid ◽  
Different Temperatures ◽  
Hydrolysis Of ◽  
Monomethyl Ester

The alkaline hydrolysis of diphenic acid monomethyl ester was studied in mixtures of water with methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, tert-butyl alcohol, and acetone. The dependences of the rate constant on the concentration of the nonaqueous component at different temperatures were obtained and the activation parameters at an isodielectric composition of the reaction medium were determined. The influence of the ionic strength on the reaction rate in the mentioned media was studied and conclusions were drawn as to the role of specific interactions between the reacting ions in the kinetics and mechanism of the studied reaction.

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