Ionic Association in Ambient Temperature Chloroaluminate Molten Salts. Analysis of Electrochemical and Conductance Data

摘要

A simple model based on the validity of the Nernst-Einstein equation and a constant u sub i eta product was applied to the interpretation of conductance data for AlCl3-RC1 (R = N-(l-butyl)pyridinium or 1-methyl-3-ethylimidazolium) ambient temperature ionic liquids. The dissociation constants of RAlCl4 and RAl2Cl7 were calculated, and the experimental values of specific conductivity were reproduced with an error not exceeding 5% from ionic mobilities calculated, from electrochemically measured diffusion coefficients. This calculation suggests that about 50% of the ions are associated into ion pairs. For very basic melts (MC < or = 0.6), the formation of ion aggregates is postulated. (Author)