Effect of Water Activity on the Rate of Proton Dissociation

D. Huppert; E. Kolodney; M. Gutman; E. Nachliel

doi:10.1021/ja00389a011

Effect of Water Activity on the Rate of Proton Dissociation

D. Huppert^*, E. Kolodney, M. Gutman, E. Nachliel

^*Corresponding author for this work

Tel Aviv University

Research output: Contribution to journal › Article › peer-review

88 Scopus citations

Abstract

The rate of proton transfer from electronically excited aromatic alcohols to the solvent was measured by both steady-state and time-resolved picosecond fluorimetry. In concentrated solutions (1–6 M) of strong electrolytes (LiBr, LiClO₄, NaCl, NaClO₄, KCl, MgCl₂, MgClO₄) at pH ≫ pK*, the rates measured by the two methods were identical. The rate of dissociation decreases upon increasing the concentration of the salt. Results obtained with different salts fit a single straight line when the log of the rate constant is drawn vs. the log of water activity. Such measurements are suitable for accurate determination of a(H₂O) of concentrated solutions of strong electrolytes. It is proposed that the rate of proton dissociation is related to the free energy of proton hydrate formation.

Original language	English
Pages (from-to)	6949-6953
Number of pages	5
Journal	Journal of the American Chemical Society
Volume	104
Issue number	25
DOIs	https://doi.org/10.1021/ja00389a011
State	Published - 1982

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10.1021/ja00389a011

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title = "Effect of Water Activity on the Rate of Proton Dissociation",

abstract = "The rate of proton transfer from electronically excited aromatic alcohols to the solvent was measured by both steady-state and time-resolved picosecond fluorimetry. In concentrated solutions (1–6 M) of strong electrolytes (LiBr, LiClO4, NaCl, NaClO4, KCl, MgCl2, MgClO4) at pH ≫ pK*, the rates measured by the two methods were identical. The rate of dissociation decreases upon increasing the concentration of the salt. Results obtained with different salts fit a single straight line when the log of the rate constant is drawn vs. the log of water activity. Such measurements are suitable for accurate determination of a(H2O) of concentrated solutions of strong electrolytes. It is proposed that the rate of proton dissociation is related to the free energy of proton hydrate formation.",

author = "D. Huppert and E. Kolodney and M. Gutman and E. Nachliel",

year = "1982",

doi = "10.1021/ja00389a011",

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journal = "Journal of the American Chemical Society",

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T1 - Effect of Water Activity on the Rate of Proton Dissociation

AU - Huppert, D.

AU - Kolodney, E.

AU - Gutman, M.

AU - Nachliel, E.

PY - 1982

Y1 - 1982

N2 - The rate of proton transfer from electronically excited aromatic alcohols to the solvent was measured by both steady-state and time-resolved picosecond fluorimetry. In concentrated solutions (1–6 M) of strong electrolytes (LiBr, LiClO4, NaCl, NaClO4, KCl, MgCl2, MgClO4) at pH ≫ pK*, the rates measured by the two methods were identical. The rate of dissociation decreases upon increasing the concentration of the salt. Results obtained with different salts fit a single straight line when the log of the rate constant is drawn vs. the log of water activity. Such measurements are suitable for accurate determination of a(H2O) of concentrated solutions of strong electrolytes. It is proposed that the rate of proton dissociation is related to the free energy of proton hydrate formation.

AB - The rate of proton transfer from electronically excited aromatic alcohols to the solvent was measured by both steady-state and time-resolved picosecond fluorimetry. In concentrated solutions (1–6 M) of strong electrolytes (LiBr, LiClO4, NaCl, NaClO4, KCl, MgCl2, MgClO4) at pH ≫ pK*, the rates measured by the two methods were identical. The rate of dissociation decreases upon increasing the concentration of the salt. Results obtained with different salts fit a single straight line when the log of the rate constant is drawn vs. the log of water activity. Such measurements are suitable for accurate determination of a(H2O) of concentrated solutions of strong electrolytes. It is proposed that the rate of proton dissociation is related to the free energy of proton hydrate formation.

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JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

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ER -

Effect of Water Activity on the Rate of Proton Dissociation

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