CONFORMATIONAL EQUILIBRIUM IN 1,2-DIMETHOXYBENZENE STUDIED BY THE NONLINEAR DIELECTRIC EFFECT METHOD

The conformational equilibrium in 1,2-dimethoxybenzene (1,2-DMB) and in its benzene solutions has been studied. On the basis of experimental data for the non-linear dielectric effect (NDE) parameter, electric permittivity, density and refractive index, obtained in this work, and by applying the general statistical theory of NDE, the Gibbs energy corresponding to the trans-gauche equilibrium, the dipole moments and percentages of the two conformers were calculated. The results reveal the predominance of the trans conformer in 1,2-DMB in contrast to 1,2-dimethoxyethane (1,2-DME) studied previously [1]. The different non-linear dielectric behaviour of 1,2-DMB and 1,2-DME was compared and satisfactorily explained under the assumption of various conformational equilibria.