Novel Bile Acid-Based Cyclic Bisimidazolium Receptors for Anion Recognition

Novel deoxycholic acid-based cyclic receptors, 3 and 4, containing two imidazolium groups and m-xylene and p-xylene as spacers have been
synthesized. These receptors bind anions through hydrogen bonds utilizing two imidazolium (C−H)+ and inwardly directed methylene hydrogens
of both acetyl groups. Receptor 3 shows a moderate selectivity for fluoride ion whereas receptor 4 shows high affinity and selectivity for
chloride ion in CDCl3.