TY - JOUR
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.
UR - http://www.scopus.com/inward/record.url?scp=33845553569&partnerID=8YFLogxK
U2 - 10.1021/ja00389a011
DO - 10.1021/ja00389a011
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AN - SCOPUS:33845553569
SN - 0002-7863
VL - 104
SP - 6949
EP - 6953
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 25
ER -