Hydrogen bonding between solutes in solvents octan-1-ol and water.
The 1:1 equilibrium constants, K, for the association of hydrogen bond bases and hydrogen bond acids have been determined by using octan-1-ol solvent at 298 K for 30 acid-base combinations. The values of K are much smaller than those found for aprotic, rather nonpolar solvents. It is shown that the log K values can satisfactorily be correlated against α(H)2·β(H)2, where α(H)2 and β(H)2 are the 1:1 hydrogen bond acidities and basicities of solutes. The slope of the plot, 2.938, is much smaller than those for log K values in the nonpolar organic solvents previously studied. An analysis of literature data on 1:1 hydrogen bonding in water yields a negative slope for a plot of log K against α(H)2·β(H)2, thus showing how the use of very strong hydrogen bond acids and bases does not lead to larger values of log K for 1:1 hydrogen bonding in water. It is suggested that for simple 1:1 association between monofunctional solutes in water, log K cannot be larger than about -0.1 log units. Descriptors have been obtained for the complex between 2,2,2-trifluoroethanol and propanone, and used to analyze solvent effects on the two reactants, the complex, and the complexation constant.
Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, United Kingdom.
Michael H
MH
Abraham
Joelle M R
JM
Gola
J Enrique
JE
Cometto-Muñiz
William E
WE
Acree
D006860:Hydrogen Bonding; D000442:Octanols / Q000737:chemistry*; D012995:Solubility; D012997:Solvents / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
D000442:Octanols; D012997:Solvents; D014867:Water