A new macrocyclic anion receptor utilizing amide, amine, and 9-anthracenyl hydrogens

We have developed a new macrocyclic anion receptor 2 utilizing two amide hydrogens, two amine hydrogens and 9-anthracenyl hydrogen to bind anions. As the binding cavity formed from these hydrogens is preorganized and its size is different from that of the previously reported receptor 1 due to its cyclization, the affinity of the receptor 2 for the anion is somewhat different from that of the receptor 1. The receptor 2 binds anions through hydrogen bonds with a selectivity of H 2 PO 4 - > CH 3 CO 2 - > F - > C 6 H 5 CO 2 - > Cl - > Br - > I - while the receptor 1 binds anions with a selectivity of CH 3 CO 2 - > H 2 PO 4 - > C 6 H 5 CO 2 - > HSO 4 - > ClO 4 - > NO 3 - .