Hydrogen bonding in imidazolium salts and its implications for ambient-temperature halogenoaluminate(III) ionic liquids

Abstract

The salts [emim]X (X = Br or I, emim = 1-ethyl-3-methylimidazolium) and [emim][AlBr₄] have been prepared as solid-state models of the [emim]X–AlX₃(X = Cl or Br) ionic liquid systems. All three have been characterised crystallographically. The salts [emim]X (X = Br or I) are isomorphous and are composed of ions in an extended hydrogen-bonded network. The implications of these results for both the structure and solvent properties of the ionic liquids are discussed.