Theoretical study of (FH2X)n·Y (X = P and As, n = 1–4, Y = F−, Cl−, Br−, I−, NO3− and SO42−): The possibility of anion recognition based on pnicogen bonding

The pnicogen-bonding interaction in the (FH2X)n·Y (X = P and As, n = 1–4, Y = F−, Cl−, Br−, I−, NO3− and SO42−) complexes have been investigated by MP2 calculations. The character of pnicogen bonding in the FH2X·Y complexes has been examined by NBO analysis. The results indicate that the anion-binding ability of FH2As is stronger than that of FH2P, and the binding strength of pnicogen-bonding interaction in FH2X·Y complexes is in the sequence of SO42− > F− > Cl− > NO3− > Br− > I−. It is found that the anion-binding strength of pnicogen bonding is comparable to that of hydrogen and halogen bonding employed in the design of anion receptors, and the anion-binding ability of pnicogen bonding can be strengthened through multiple receptor-anion interactions, which suggests that the pnicogen bonding is possible to be employed in the design of anion receptors.