Imidazolium Cations in Organic Chemistry: From Chemzymes to Supramolecular Building Blocs

The interest of imidazolium cations has grown enormously in the last few years especially in the field of green solvents and ionic liquids. Much attention has been focused on their physico-chemical properties and two properties can be highlighted: (i) the formation of carbenic species; and (ii) the formation of 'supramolecules' via electrostatic, H-bonding and/or aromatic stacking interactions. The last property can be used to modify the molecular reactivity by the formation of supramolecular complexes between guests (reactive species) and the cationic receptors (imidazolium groups). The aim of this review is to bring together the areas of supramolecular assembly and imidazolium cations. Both imidazole and imidazolium cations are reviewed but only in their relation to achieving supramolecular organization.