Molecular dynamics simulation study of N-butylpyridinium tetrafluoroborate/water binary system
Molecular dynamics simulation method was used to study the microscopic structure of the binary sys-tem of the ionic liquid N-butylpyridinium tetrafluoroborate([BPy]BF4)with water.Radial distribution func-tions(RDFs)for different components were compared.The results showed that,with the increase of the propor-tion of[BPy]BF4,the peaks of RDFs for two certain atoms between water molecule and anion,water molecule and pyridine ring in cation,anion and pyridine ring in cation presented an increasing trend,but that of the ter-minal carbon of the butyl side-chain in[BPy]BF4had no obvious change.Spatial distribution functions intui-tively reflected that the anions were mainly distributed around the pyridine ring of the cation,water molecules were almost equally distributed around anion,and the probability increased with the increase of the proportion of ionic liquids.Numbers and lifetimes of hydrogen bonding between water molecules were also calculated under different proportions of ionic liquid,and the results showed some regular changes.
Ionic liquidMolecular dynamics simulationRadial distribution functionsSpatial distribution functionsHydrogen bond