Effects of the Dielectric Constant on the Association Equilibria of Aliphatic Monocarboxylic Acids in Solution

Abstract

AbstractMeasurements of shifts of the resonance of the hydroxylic protons of aliphatic monocarboxylic acids in binary and ternary mixtures with aprotic solvents made at a given concentration of acid show a linear dependence of the shift on the reciprocal of the dielectric constant of the medium.Furthermore, interesting regularities in the paramagnetic dilution shifts of the pure acids are evidenced. These shifts are interpreted as an effect of the law of mass action on the complex equilibria in solution. It is shown that the equilibrium between the open and cyclic dimers might be the predominant equilibrium down to low concentrations.