Pyridinium amide-based simple synthetic receptor for selective recognition of dihydrogenphosphate

A new fluorescent receptor 1 built on biphenyl motif has been designed and synthesized. Pyridinium amide moiety in 1 acts as binding site and shows selective complexation of isophthalate and H 2 PO 4 - under the mastery of biphenyl spacer. Binding-induced increase in emission was used to determine the selectivity and sensitivity of 1 toward a series of anions such as different dicarboxylates, HSO 4 - , ClO 4 - , and H 2 PO 4 - . The binding characteristics were established by 1H NMR, UV–vis, and fluorescence spectroscopic methods.