Binding and selectivity of dihydrogen phosphate by H-bond donors and acceptors in a tripodal-based thiourea receptor

Abstract Anion binding properties of a quinoline-based tripodal tris-thiourea receptor have been studied for several oxoanions including perchlorate, nitrate, hydrogen sulfate, and dihydrogen phosphate by 1 H NMR and UV–vis titrations in DMSO. Results show that the receptor selectively binds dihydrogen phosphate with a 1:1 stoichiometry. Ab initio calculations based on density functional theory (DFT) suggest that the dihydrogen phosphate is encapsulated within the host’s cavity via six NH⋯O and two N⋯OH interactions.