Some Observations about the Diffusion Coefficients of Anionic Transition Metal Halide Complexes in Room‐Temperature Haloaluminate Ionic Liquids

Abstract

Stokes‐Einstein products that were derived from electrochemical data for monomeric and polymeric anionic transition metal halide complexes in the basic aluminum chloride‐1‐methyl‐3‐ethylimidazolium chloride room‐temperature ionic liquid and its bromide analog are shown to vary stepwise with the overall charge on the complex ion. These observations are reconciled in terms of ion‐ion interactions between the melt cations and the anionic complexes which lead to diffusing entities with larger solvodynamic radii than expected. The number of associated cations appears to increase as the charge on the transition metal complex becomes more negative.