A density functional investigation of 1,3-bis(4-nitrophenyl)urea as anion receptor

Abstract

The B3LYP/6-311+G(d,p) optimized structures of 1,3-bis(4-nitrophenyl)urea receptor (1) and its complexes with halide ions F-, Cl-, Br-, oxygen-containing anions NO2-, NO3-, HCO3-, HSO4-, H2PO4-, CH3COO-and C6H5COO-ions were obtained. Binding energies and thermodynamic properties of binding between the receptor 1 and these anions were determined. Binding energies of receptor 1 are in decreasing orders: CH3COO-> HCO3-∼ C6H5COO->NO2->H2PO4->NO3->HSO4-for oxygen-containing anions and F-> Cl-> Br-for halide ions. It was found that the binding energies depend on their hydrogen-bond distances of their binding atoms. It was also found that the complexes of receptor 1 and the studied anions are formed via two-point hydrogen-bonding interactions. © 2009 Elsevier B.V. All rights reserved.