Nucleophilic addition to olefins. Part 25. Kinetics of hydrolysis of substituted .beta.-nitrostyrenes. Transition-state imbalances and intrinsic rate constants for three different types of nitronate ion forming processes. Relevance to the nitroalkane anomaly

1989 ◽  
Vol 111 (15) ◽  
pp. 5893-5902 ◽  
Author(s):  
Claude F. Bernasconi ◽  
Peter Paschalis
Keyword(s):  
Transition State ◽  
Rate Constants ◽  
Nucleophilic Addition ◽  
Intrinsic Rate ◽  
Kinetics Of Hydrolysis ◽  
Different Types ◽  
Kinetics Of ◽  
Hydrolysis Of

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.

Stability of the Nerve Gas Antidote BIS (4-Hydroxyiminomethyl-1-Pyridinomethyl) Ether Dichloride (Toxogonin®)

1968 ◽  
Vol 2 (9) ◽  
pp. 234-243 ◽  
Author(s):  
Inga Christenson
Keyword(s):  
Aqueous Solution ◽  
Hydrochloric Acid ◽  
Sodium Hydroxide ◽  
Rate Constants ◽  
Kinetics Of Hydrolysis ◽  
Dilute Aqueous Solution ◽  
Nerve Gas ◽  
Ph Range ◽  
Kinetics Of ◽  
Hydrolysis Of

The products and kinetics of hydrolysis of the nerve gas antidote bis(4-hydroxyiminomethyl - 1 - pyridinemethyl) ether dichloride (Toxogonin ®) have been investigated. A survey of these studies is given: The hydrolytic reactions were studied in the pH range 1 M hydrochloric acid to 1 M sodium hydroxide at 25, 45, 75 and 85° C. Rate constants were determined in dilute aqueous solution, generally with an initial Toxogonin concentration of 0.01 mg per ml. In addition, a report is given concerning two-year storage of 25 percent (w/v) Toxogonin solutions at pH 2.5, 3.0 and 3.5. The solutions were stored in glass or polypropylene ampuls at 5, 15, 25 and 45°C. At 5 and 15C° decomposition was negligible, at 25 and 45 °C average decomposition was 1.5 percent and 3.3 percent, respectively.

Kinetics of the hydrolysis of acetic anhydride and the reaction of 4-nitrophenyl acetate with imidazole in aqueous-organic mixed solvents

1974 ◽  
Vol 27 (7) ◽  
pp. 1423 ◽  
Author(s):  
DG Oakenfull
Keyword(s):  
Acetic Anhydride ◽  
Organic Solvent ◽  
Transition State ◽  
Activity Coefficients ◽  
Butyl Alcohol ◽  
Dimethyl Sulphoxide ◽  
Kinetics Of Hydrolysis ◽  
State Activity ◽  
Kinetics Of ◽  
Hydrolysis Of

With the general aim of elucidating the role of water structure in the kinetics of hydrolysis, a comparative study has been made of the kinetics of the hydrolysis of acetic anhydride and the reaction of 4-nitrophenyl acetate with imidazole in mixtures of water with ethanol, t-butyl alcohol, dimethyl sulphoxide and dioxan. Both rate constants were always reduced by the addition of organic solvent. Transition state activity coefficients were measured for both reactions in dimethyl sulphoxide-water mixtures and compared with the activity coefficient of phenylalanine (a model zwitterionic transition state). Activation parameters were measured for the hydrolysis of aceticanhydride in t-butyl alcohol-water and dimethyl sulphoxide-water mixtures. Semilogarithmic plots of rate constant against Winstein's Y-value were non-linear for some of the solvents and this fact, coupled with the effect of dimethyl sulphoxide on the transition state activity coefficients, leads to the conclusion that specific interactions of the solvent with the reactants and with the transition state could be of major importance in controlling the reaction rate.There was no obvious relationship between the effect of an organic solvent on the kinetics of hydrolysis of acetic anhydride and its effect on the structure of water.

Kinetics of the hydrolysis of acetic anhydride in concentrated salt solutions

1971 ◽  
Vol 24 (12) ◽  
pp. 2547 ◽  
Author(s):  
DG Oakenfull
Keyword(s):  
Free Energy ◽  
Acetic Anhydride ◽  
Transition State ◽  
Activity Coefficients ◽  
Rate Constants ◽  
Water Structure ◽  
Salt Solutions ◽  
Measured Activity ◽  
Kinetics Of ◽  
Hydrolysis Of

The kinetics of the hydrolysis of acetic anhydride have been investigated in concentrated salt solutions at 20�. Sine salts were used in concentrations of up to 5 mol 1-1; all inhibited the reaction. ��� The salt effect was resolved into its component effects on the reactants and the transition state by use of the Bronsted-Bjerrum equation to calculate transition state activity coefficients from rate constants and measured activity coefficients of acetic anhydride. The effect of a salt on the free energy of the reactants was always significant and in some cases it was the major component of the effect of the salt on the free energy of activation. The enthalpy and entropy of transfer from water to 1 mol l-1 sodium chloride, for both acetic anhydride and the transition state, show the enthalpy-entropy compensation effect which is typical of aqueous solutions. ��� These salt effects are considered to be part of the general phenomenon of the effect of salts on the activity coefficients of non-electrolytes. The inhibition is not caused by formation of a complex between salt and acetic anhydride. Rate constants could not be correlated with dielectric constant and ionic strength, using Gold's equation, and changes in water structure which occur in these salt solutions were shown to have no direct effect on the reaction rate.

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