Dihydrogen Phosphate Selective Anion Receptor Based on Acylhydrazone

Abstract

Anion receptor 1 based on acylhydrazone has been designed and synthesized. UV-vis and 1 H NMR titration showed that receptor 1 is selective receptor for dihydrogen phosphate (H2PO4 − ). Dihydrogen phosphate was complexed by the receptor 1 via at least 4 hydrogen bonding interactions, contributing from two amide N-Hs and two imine C-Hs. In addition, nitrogen in the aromatic ring could make 2 additional hydrogen bondings with OH groups in the dihydrogen phosphate. However, the receptor 1 could make only 4 hydrogen bonds with halides. Therefore, receptor 1 could bind anions through hydrogen bonds with a selectivity in the order of H2PO4 − > Br − > Cl − in highly polar solvent such as DMSO.