The apparent dipole moment of NN-dimethyl-4-nitroaniline in solution

Abstract

Apparent dipole moments have been measured for NN-dimethyl-4-nitroaniline in dilute solution in dioxan, chloro-form, and cis-1,2-dichloroethene. Differences in the predicted moments, much greater than the experimental uncertainties, were found on applying equations of Guggenheim, Onsager and Kirkwood directly. All three treatments were in closer agreement when referred to a common state. The dipole moments observed indicated that specific ‘solvent effects’ were operative in these systems. Tentative explanations, which supply some semiquantitative agreement with observation, have been attempted.