Carbon-13 Isotope Effects in the Oxidation of Acetic Acid

1965 ◽  
Vol 69 (4) ◽  
pp. 1428-1429 ◽  
Author(s):  
Mieczyslaw Zielinski
Keyword(s):  
Acetic Acid ◽  
Isotope Effects

α-DEUTERIUM KINETIC ISOTOPE EFFECTS IN SOLVOLYSES OF endo-NORBORNYL p-BROMOBENZENESULFONATE

1965 ◽  
Vol 43 (8) ◽  
pp. 2254-2258 ◽  
Author(s):  
C. C. Lee ◽  
Edward W. C. Wong
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Aqueous Dioxane ◽  
Kinetic Isotope ◽  
Different Temperatures

endo-Norbornyl-2-d p-bromobenzenesulfonate was synthesized and the isotope effects, as measured by kH/kD, were determined over a range of temperatures for solvolyses in 30% water – 70% dioxane, acetic acid, and formic acid. Values of kH/kD are of the order of 1.20. The data appear to indicate slightly higher isotope effects as the solvents are changed from aqueous dioxane to acetic acid to formic acid, as well as somewhat higher isotope effects at lower temperatures. Possible mechanistic implications of these results are presented. Relative titrimetric acetolysis rates, kexo/kendo, at different temperatures, and enthalpies and entropies of activation for these acetolyses are evaluated and discussed.

Chemistry of episulfides. II. The reactivities of propylene sulfide and propylene oxide towards acetic acid

1968 ◽  
Vol 46 (7) ◽  
pp. 1043-1046 ◽  
Author(s):  
Neil S. Isaacs ◽  
K. Neelakantan
Keyword(s):  
Acetic Acid ◽  
Propylene Oxide ◽  
Isotope Effects ◽  
Preexponential Factor ◽  
Solvent Isotope ◽  
Solvent Isotope Effects

The rates and products of solvolysis of propylene oxide and propylene sulfide in acetic acid have been determined. The results show that terminal attack is preferred, although not exclusively, and that the sulfide is the less reactive by a factor of 50–60. This difference is accounted for mainly in the preexponential factor. Solvent isotope effects are also observed.

Ketonization of the unusually acidic elongated enol generated by flash photolytic decarboxylation of p-formylphenylacetic acid in aqueous solution

2008 ◽  
Vol 86 (2) ◽  
pp. 101-104 ◽  
Author(s):  
Yvonne Chiang ◽  
Kirill Kolmakov ◽  
A Jerry Kresge
Keyword(s):  
Aqueous Solution ◽  
Acetic Acid ◽  
Sodium Hydroxide ◽  
Perchloric Acid ◽  
Flash Photolysis ◽  
Isotope Effects ◽  
Solvent Isotope ◽  
Solvent Isotope Effects

Rates of photolysis of p-formylphenylacetic acid were measured flash photoytically in perchloric acid and sodium hydroxide solutions, and also in acetic acid, biphosphate ion, and tris-(hydroxymethyl)methaneammonium ion buffers, using H2O and D2O as solvents. The results provide rate profiles and solvent isotope effects, which indicate that photolysis occurs through an elongated enol intermediate. This enol is unusually strongly acidic, by some two to three pQa units, when compared with simple non-elongated enols.Key words: flash photolysis, elongated enols, rate profiles, solvent isotope effects.

THE CHROMIC ACID OXIDATION OF ARYL TRIFLUOROMETHYL ALCOHOLS: ISOTOPE AND SUBSTITUENT EFFECTS

1964 ◽  
Vol 42 (2) ◽  
pp. 439-446 ◽  
Author(s):  
Ross Stewart ◽  
Donald G. Lee
Keyword(s):  
Acetic Acid ◽  
Acid Solution ◽  
Chromic Acid ◽  
Isotope Effects ◽  
Acetic Acid Solution ◽  
Substituent Effects ◽  
Acid Oxidation ◽  
Unimolecular Decomposition ◽  
Chromic Acid Oxidation ◽  
Deuterium Isotope Effects

The mechanism of the chromic acid oxidation of eight aryltrmuoromethylcarbinols has been studied in acetic acid solution. Electron-donating substituents accelerate the reaction and a good correlation of rate with σ+ values has been found. The rho value is −1.01. Deuterium isotope effects for the oxidation of five of these compounds have been determined and the magnitude of the isotope effect has been found to correlate inversely with the ease of oxidation of the alcohol.The results are interpreted in terms of a unimolecular decomposition of the chromate ester of the alcohol.

Article

1999 ◽  
Vol 77 (5-6) ◽  
pp. 744-751
Author(s):  
Robert Eliason
Keyword(s):  
Acetic Acid ◽  
Carboxylic Acids ◽  
Hydrogen Isotope ◽  
Isotope Effects ◽  
Water Concentration ◽  
Chloroacetic Acid ◽  
Water Effect ◽  
First Order ◽  
Acid Catalyzed ◽  
Catalyzed Reactions

Acid-catalyzed decomposition of diazodiphenylmethane (DDM) has been studied in DMSO containing varying amounts of water. The reaction was found to be first-order in DDM and first-order in acid. The Brønsted plot for a series of carboxylic acids is curved with the H+ point falling below the curve defined by the carboxylic acids. In near-anhydrous DMSO, kinetic hydrogen isotope effects (KIEs) are 1.7 and 1.6 for acetic acid and chloroacetic acid, respectively. The chloroacetic acid KIE increases with increasing water concentration, rising to 2.9 at 3.6 M water. As a function of [H2O], kHA for chloroacetic acid shows a sharply defined minimum occurring at 1 M water. This behavior and the water effect on KIE suggest that the carboxylic acid-catalyzed reactions in near-anhydrous DMSO do not use the ASE-2 mechanism attributed to the reaction of DDM in hydroxylic solvents. A mechanism, leading to an azoalkane, is suggested. Either directly or indirectly, this may lead to diphenylcarbene, which would account for the observed products: benzophenone, benzhydrol, and benzhydryl esters. For the H+ catalyzed decomposition of DDM in near-anhydrous DMSO, benzophenone is not found among the products, and we suggest that this reaction does not undergo a change in mechanism and continues to use the ASE-2 mechanism.Key words: decomposition mechanism, kinetics, solvent effect, reaction with carboxylic acids.

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