Calix[n]pyrroles as anion and ion-pair complexants

This chapter covers advances in calixpyrrole chemistry and specifically in the application of these species as anion and ion-pair complexation agents over the last 5 years. Over this time, the chemistry of these easy-to-make macrocycles advanced with the discovery of the ion-pair complexation properties of calixpyrroles, in addition to the development of strapped calixpyrroles that incorporate extra hydrogen bond donors and possess higher affinities for anions than the parent macrocycle. Calixpyrroles have also been employed as anion complexants in solvent–solvent extraction and in polymers. They have also been shown to function as lipid bilayer transport agents for salts and as organocatalysts