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 NO 2 - , NO 3 - , HCO 3 - , HSO 4 - , H 2 PO 4 - , CH 3COO − and C 6H 5COO − 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: CH 3COO − > HCO 3 − ∼ C 6H 5COO − > NO 2 - > H 2 PO 4 - > NO 3 - > HSO 4 - 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.