Addition to the Carbon-Carbon Triple Bond. The Reaction of Acetic Acid with 3-Hexyne

Author: Lemaire, Henry

Year: 1950

Degree: Dissertation (Ph.D.)

Advisor: Lucas, Howard J.

Committee Member: Unknown, Unknown

Option: Chemistry; Physics

DOI: 10.7907/5g6h-b137

Abstract

The mechanism of the mercury-catalyzed addition to the carbon-carbon triple bond has been investigated. Acetic acid was used as the solvent and one reactant. The other reactant was 3-hexyne. The course of the reaction was followed by bromine titration and by a special indicator method. The addition was found to take place in two discrete steps, forming 3-acetoxyhexene-3 and 3-hexanone.

The rate of the initial reaction was determined for a range of initial concentrations of hexyne and the catalysts. When mercuric acetate and perchloric acid were used as the catalysts , the initial rates were found to be interpretable on the assumption that the reactive species was a 1 to 1 to 1 complex formed by the 3-hexyne, the mercuric acetate, and the perchloric acid. By means of indicator studies the existence of the 1 to 1 to 1 complex (probably a hexyne-mercuric monoacetate cation) was proved and its equilibrium constant measured.

The indicator studies were extended to the measurement of the basicities of weak bases in acetic acid. A simple relationship was found between the observed ionization constant and the thermodynamic activity constant. New values were found for the basic strengths of dioxane, acetonitrile, p-toluene-sulfonamide, water, acetanilide, acetamide, and urea.

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