Imidazolium and pyridinium based receptors for anion recognition and sensing

Design and synthesis of receptors for the selective sensing and binding of anionic species are of great interest in host-guest chemistry, largely due to anions play ubiquitous roles in both chemical and biochemical process. Imidazolium and pyridinium based receptors are very important receptors with positively charged moieties. These kinds of anion receptors possess a great deal of merits such as various host structures, synergistic effects of hydrogen bonding, hydrophobic interaction, electrostatic interaction, π-π stacking, anion-π interaction, and so on. The design, structure and anion recognition and sensing of imidazolium and pyridinium based receptors have been reviewed.