Aromatic reactivity. Part LVI. Solvent isotope effects in cleavage of aryltrimethylstannanes by acetic acid and aryltrimethylsilanes by trifluoroacetic acid

1974 ◽  
pp. 596 ◽  
Author(s):  
Colin Eaborn ◽  
Ian D. Jenkins ◽  
David R. M. Walton
Keyword(s):  
Acetic Acid ◽  
Trifluoroacetic Acid ◽  
Isotope Effects ◽  
Solvent Isotope ◽  
Solvent Isotope Effects

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.

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.

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