Note on the proton-donating ability of water in hydrogen-bonding reactions

Abstract

A vapour pressure method has been used to determine the partial pressure of water as a function of the concentrations of dissolved water and quinoline in the solvents diphenylmethane, n-hexadecane and several mixtures of diphenylmethane and hexadecane. Inferred values of the equilibrium constant for formation of quinoline · H2O and the effects of solvents on this constant are analogous to those determined previously for pyridine · H2O. In disagreement with a recent report, it is concluded that water is a much poorer proton donor than phenol, but similar in proton-donating ability to aliphatic alcohols.