Amide-functionalized pillar[5]arenes as a novel class of macrocyclic receptors for the sensing of H2PO4- anion.

A novel class of amide-functionalized pillar[5]arenes, that is, alkyl and aryl amide derivatives, has been synthesized. Highly selective binding of the dihydrogen phosphate anion over a range of anions by the new synthetic receptors is reported. First, the "binding strength-selectivity" relationship has been decided for the pillar[5]arene/anion systems.