Proximate charge effects. 3. Enthalpies of solvent transfer of reactants and transition states in the saponification of acetylcholine

Paul Haberfield, Jeffrey E. Pessin

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6 Citations (Scopus)

Abstract

The rates and activation enthalpies of the alkaline hydrolysis of acetylcholine were measured in water, in 60 mol % ethanol-water, and in 85 mol % ethanol-water. Unlike the alkaline hydrolysis of ethyl acetate, which exhibited a large increase in ΔH on going from water solvent to 60 mol % ethanol-water solvent, no such solvent effect was observed in the case of acetylcholine. Calorimetric determination of the relative enthalpies of the reactants in water and in aqueous ethanol revealed that whereas there was a large desolvation of the ethyl acetate saponification transition state in aqueous ethanol relative to water, no such desolvation of the acetylcholine saponification transition state took place.

Original languageEnglish (US)
Pages (from-to)526-528
Number of pages3
JournalJournal of the American Chemical Society
Volume105
Issue number3
StatePublished - 1983
Externally publishedYes

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Saponification
Acetylcholine
Enthalpy
Water
Ethanol
Hydrolysis
Chemical activation
Hydrogen

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

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abstract = "The rates and activation enthalpies of the alkaline hydrolysis of acetylcholine were measured in water, in 60 mol {\%} ethanol-water, and in 85 mol {\%} ethanol-water. Unlike the alkaline hydrolysis of ethyl acetate, which exhibited a large increase in ΔH‡ on going from water solvent to 60 mol {\%} ethanol-water solvent, no such solvent effect was observed in the case of acetylcholine. Calorimetric determination of the relative enthalpies of the reactants in water and in aqueous ethanol revealed that whereas there was a large desolvation of the ethyl acetate saponification transition state in aqueous ethanol relative to water, no such desolvation of the acetylcholine saponification transition state took place.",
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T1 - Proximate charge effects. 3. Enthalpies of solvent transfer of reactants and transition states in the saponification of acetylcholine

AU - Haberfield, Paul

AU - Pessin, Jeffrey E.

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Y1 - 1983

N2 - The rates and activation enthalpies of the alkaline hydrolysis of acetylcholine were measured in water, in 60 mol % ethanol-water, and in 85 mol % ethanol-water. Unlike the alkaline hydrolysis of ethyl acetate, which exhibited a large increase in ΔH‡ on going from water solvent to 60 mol % ethanol-water solvent, no such solvent effect was observed in the case of acetylcholine. Calorimetric determination of the relative enthalpies of the reactants in water and in aqueous ethanol revealed that whereas there was a large desolvation of the ethyl acetate saponification transition state in aqueous ethanol relative to water, no such desolvation of the acetylcholine saponification transition state took place.

AB - The rates and activation enthalpies of the alkaline hydrolysis of acetylcholine were measured in water, in 60 mol % ethanol-water, and in 85 mol % ethanol-water. Unlike the alkaline hydrolysis of ethyl acetate, which exhibited a large increase in ΔH‡ on going from water solvent to 60 mol % ethanol-water solvent, no such solvent effect was observed in the case of acetylcholine. Calorimetric determination of the relative enthalpies of the reactants in water and in aqueous ethanol revealed that whereas there was a large desolvation of the ethyl acetate saponification transition state in aqueous ethanol relative to water, no such desolvation of the acetylcholine saponification transition state took place.

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JO - Journal of the American Chemical Society

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