Proximate charge effects. 2. Enthalpies of solvent transfer in the choline-anhydrocholine equilibrium

Paul Haberfield, Jeffrey E. Pessin

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Equilibrium constants for the choline-anhydrocholine equilibrium, eq 1, +(CH3)3NCH2CH2OH + OH- → (CH3)3NCH2CH2O- + H2O, were measured conductometrically in water, aqueous alcohol, and aqueous dimethyl sulfoxide at several temperatures. On going to progressively less H-bonding media, there was a large shift of the equilibrium constant toward anhydrocholine (to the right) accompanied by an even larger exothermic shift of the enthalpy of reaction. Calorimetric measurement of the enthalpies of solvent transfer revealed that, in the case of the aqueous alcohol solvents, the exothermic shift was caused by enhanced solvation of anhydrocholine, +(CH3)3NCH2CH2O -, by the less polar media. In the comparison of aqueous ethanol with aqueous Me2SO, the dominant factor was found to be the very great desolvation of both hydroxide ion and anhydrocholine in the less H-bonding medium.

Original languageEnglish (US)
Pages (from-to)6191-6194
Number of pages4
JournalJournal of the American Chemical Society
Volume104
Issue number23
StatePublished - 1982
Externally publishedYes

Fingerprint

Equilibrium constants
Choline
Enthalpy
Alcohols
Dimethyl sulfoxide
Solvation
Dimethyl Sulfoxide
Ethanol
Temperature
Water
Ions
hydroxide ion

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

Proximate charge effects. 2. Enthalpies of solvent transfer in the choline-anhydrocholine equilibrium. / Haberfield, Paul; Pessin, Jeffrey E.

In: Journal of the American Chemical Society, Vol. 104, No. 23, 1982, p. 6191-6194.

Research output: Contribution to journalArticle

@article{185558eb56974c80a195176638e52883,
title = "Proximate charge effects. 2. Enthalpies of solvent transfer in the choline-anhydrocholine equilibrium",
abstract = "Equilibrium constants for the choline-anhydrocholine equilibrium, eq 1, +(CH3)3NCH2CH2OH + OH- → (CH3)3NCH2CH2O- + H2O, were measured conductometrically in water, aqueous alcohol, and aqueous dimethyl sulfoxide at several temperatures. On going to progressively less H-bonding media, there was a large shift of the equilibrium constant toward anhydrocholine (to the right) accompanied by an even larger exothermic shift of the enthalpy of reaction. Calorimetric measurement of the enthalpies of solvent transfer revealed that, in the case of the aqueous alcohol solvents, the exothermic shift was caused by enhanced solvation of anhydrocholine, +(CH3)3NCH2CH2O -, by the less polar media. In the comparison of aqueous ethanol with aqueous Me2SO, the dominant factor was found to be the very great desolvation of both hydroxide ion and anhydrocholine in the less H-bonding medium.",
author = "Paul Haberfield and Pessin, {Jeffrey E.}",
year = "1982",
language = "English (US)",
volume = "104",
pages = "6191--6194",
journal = "Journal of the American Chemical Society",
issn = "0002-7863",
publisher = "American Chemical Society",
number = "23",

}

TY - JOUR

T1 - Proximate charge effects. 2. Enthalpies of solvent transfer in the choline-anhydrocholine equilibrium

AU - Haberfield, Paul

AU - Pessin, Jeffrey E.

PY - 1982

Y1 - 1982

N2 - Equilibrium constants for the choline-anhydrocholine equilibrium, eq 1, +(CH3)3NCH2CH2OH + OH- → (CH3)3NCH2CH2O- + H2O, were measured conductometrically in water, aqueous alcohol, and aqueous dimethyl sulfoxide at several temperatures. On going to progressively less H-bonding media, there was a large shift of the equilibrium constant toward anhydrocholine (to the right) accompanied by an even larger exothermic shift of the enthalpy of reaction. Calorimetric measurement of the enthalpies of solvent transfer revealed that, in the case of the aqueous alcohol solvents, the exothermic shift was caused by enhanced solvation of anhydrocholine, +(CH3)3NCH2CH2O -, by the less polar media. In the comparison of aqueous ethanol with aqueous Me2SO, the dominant factor was found to be the very great desolvation of both hydroxide ion and anhydrocholine in the less H-bonding medium.

AB - Equilibrium constants for the choline-anhydrocholine equilibrium, eq 1, +(CH3)3NCH2CH2OH + OH- → (CH3)3NCH2CH2O- + H2O, were measured conductometrically in water, aqueous alcohol, and aqueous dimethyl sulfoxide at several temperatures. On going to progressively less H-bonding media, there was a large shift of the equilibrium constant toward anhydrocholine (to the right) accompanied by an even larger exothermic shift of the enthalpy of reaction. Calorimetric measurement of the enthalpies of solvent transfer revealed that, in the case of the aqueous alcohol solvents, the exothermic shift was caused by enhanced solvation of anhydrocholine, +(CH3)3NCH2CH2O -, by the less polar media. In the comparison of aqueous ethanol with aqueous Me2SO, the dominant factor was found to be the very great desolvation of both hydroxide ion and anhydrocholine in the less H-bonding medium.

UR - http://www.scopus.com/inward/record.url?scp=0000733188&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0000733188&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0000733188

VL - 104

SP - 6191

EP - 6194

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

SN - 0002-7863

IS - 23

ER -