Solvent isotope effects on pKa of anilinium ions in aqueous sulfuric acid

1973 ◽  
Vol 77 (12) ◽  
pp. 1557-1562 ◽  
Author(s):  
J. L. Jensen ◽  
M. P. Gardner
Keyword(s):  
Sulfuric Acid ◽  
Isotope Effects ◽  
Aqueous Sulfuric Acid ◽  
Solvent Isotope ◽  
Solvent Isotope Effects

Mechanism of decarboxylation of substituted anthranilic acids at high acidity

1970 ◽  
Vol 48 (21) ◽  
pp. 3349-3353 ◽  
Author(s):  
G. E. Dunn ◽  
S. K. Dayal
Keyword(s):  
Sulfuric Acid ◽  
Anthranilic Acid ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Carboxyl Group ◽  
Kinetic Isotope ◽  
Anthranilic Acids ◽  
Ph Range ◽  
Solvent Isotope ◽  
Solvent Isotope Effects

The rates of decarboxylation of 4-methyl-, 4-methoxy-, and unsubstituted anthranilic acids have been determined in aqueous buffers over the pH range 2.5–3.8. Electron-releasing substituents increase the rates of ring-protonation about equally for an acid and its anion, and decrease the ratio of decarboxylation to deprotonation of the protonated acid. Rates, 13C-carboxyl kinetic isotope effects, and deuterium solvent isotope effects have been determined for the decarboxylation of anthranilic acid in aqueous sulfuric acid up to 10 M. No evidence for decarboxylation by cleavage of the unionized carboxyl group was obtained.

scholarly journals Solvent isotope effects and the pH dependence of laccase activity under steady-state conditions.

1985 ◽  
Vol 260 (29) ◽  
pp. 15561-15565
Author(s):  
G B Koudelka ◽  
F B Hansen ◽  
M J Ettinger
Keyword(s):  
Steady State ◽  
Laccase Activity ◽  
Isotope Effects ◽  
Ph Dependence ◽  
Solvent Isotope ◽  
Solvent Isotope Effects

scholarly journals Rate and Product Studies with 1-Adamantyl Chlorothioformate under Solvolytic Conditions

2021 ◽  
Vol 22 (14) ◽  
pp. 7394
Author(s):  
Kyoung Ho Park ◽  
Mi Hye Seong ◽  
Jin Burm Kyong ◽  
Dennis N. Kevill
Keyword(s):  
Rate Constants ◽  
Isotope Effects ◽  
Ion Pairs ◽  
Carbonyl Sulfide ◽  
Activation Parameters ◽  
Chloride Ions ◽  
Reaction Channels ◽  
Decomposition Pathway ◽  
Solvent Isotope ◽  
Solvent Isotope Effects

A study was carried out on the solvolysis of 1-adamantyl chlorothioformate (1-AdSCOCl, 1) in hydroxylic solvents. The rate constants of the solvolysis of 1 were well correlated using the Grunwald–Winstein equation in all of the 20 solvents (R = 0.985). The solvolyses of 1 were analyzed as the following two competing reactions: the solvolysis ionization pathway through the intermediate (1-AdSCO)+ (carboxylium ion) stabilized by the loss of chloride ions due to nucleophilic solvation and the solvolysis–decomposition pathway through the intermediate 1-Ad+Cl− ion pairs (carbocation) with the loss of carbonyl sulfide. In addition, the rate constants (kexp) for the solvolysis of 1 were separated into k1-Ad+Cl− and k1-AdSCO+Cl− through a product study and applied to the Grunwald–Winstein equation to obtain the sensitivity (m-value) to change in solvent ionizing power. For binary hydroxylic solvents, the selectivities (S) for the formation of solvolysis products were very similar to those of the 1-adamantyl derivatives discussed previously. The kinetic solvent isotope effects (KSIEs), salt effects and activation parameters for the solvolyses of 1 were also determined. These observations are compared with those previously reported for the solvolyses of 1-adamantyl chloroformate (1-AdOCOCl, 2). The reasons for change in reaction channels are discussed in terms of the gas-phase stabilities of acylium ions calculated using Gaussian 03.

Kinetic solvent isotope effects in the additions of bromine and 4-chlorobenzenesulfenyl chloride to alkenes and alkynes

1979 ◽  
Vol 44 (24) ◽  
pp. 4221-4224 ◽  
Author(s):  
Agnieszka Modro ◽  
George H. Schmid ◽  
Keith Yates
Keyword(s):  
Isotope Effects ◽  
Solvent Isotope ◽  
Solvent Isotope Effects
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