4-(N,N-dimethylamino)benzoic acid as a new class of simple chromogenic and fluorogenic anion host exhibiting high selectivity to HPO42- and SO42-

Commercially available 4-(N.N-dirnethylamino)benzoic acid (1) was directly applied for anion recognition in CH3CN. It showed remarkable affinity and selectivity to divalent anions HPO42- and SO42- over monovalent anions Such as H2PO4-, HSO4-, ClO4-, BF4-, PF6-, and NO3- in terms of UV-vis and fluorescence durations. The combination of the basicity and charge density Of guest anions played an important role in the selectivity of host 1 toward anions.