Determination of the complexes between dimethylphenols and pyridine by a dielectric constant method in non-polar solvents

Abstract

The apparent equilibrium constants for the association of pyridine with dimethylphenols in benzene and in cyclohexane at 25 °C have been measured by the method of dielectric constant variation, in order to check and extend the results obtained by spectroscopic methods. Solvent effects were detected. Excess of dipole moments have been derived and related with pK_a values from the literature. The influence of the relative positions of the methyl substituents on complex formation are discussed qualitatively.