Interconversion equilibrium of para-meta isomerization of alkylbenzenes

The equilibrium of the reaction of para-meta isomerization of alkylbenzenes in the liquid phase was studied. The thermodynamic characteristics of the reaction were determined and interpreted. It was shown that the enthalpic term of the interaction between substituents in the case of their meta arrangement in the molecule depends on the effective size of the substituents. An approach to the prediction of the equilibrium constants of para-meta isomerization is proposed.