The Calculations Of Structural Properties And The Interaction Between The Anions And Cations In Ionic Liquids

The unique solvent properties of ionic liquids (ILs) have become a common topic of research in electrochemistry,synthetic and catalytic chemistry. In our work, the study of the interaction between the anions and cations in ILs ,which might lead to a better understanding of their structure一activity relationship. Quantum chemistry calculations have been used to investigate the interaction between the water molecules and ILs based on the imidazoliume anion with different cations at a different angle. The inieraction between the anions and the cations in the ILs was firstly focused on using the density funetional theory (DFT) and HF. Anions have been gradually placed in different regions around imidazoliume cation and the interaction energies between the anions and the cations have been caleulated in this paper. Theoretical results indicate that there are four active regions in the vicinity of the imidazoliume cations.It has been recognized that the hydrogen bonds have a significant influence on the physical properties of imidazolium ionic liquids; however, most of the simulations were limited to single ionic species and/or single ion-pairs of some specific ionic liquids. It is difficult to find some general rules of hydrogen to understand the hydrogen bonds in the imidazolium ionic liquids, a series of ionic liquids have been systematically studied by ab initio and DFT in this work. The structures of not only the single ions and single ion-pairs but also of multiple ionpairshave been investigated. The hydrophobic PF6- anion could not form a stable complex with the water molecules at the density functional theory (DFT) level. Further studies indicate that the cation could also form a strong interaction with the water molecules.A close relation between the experimental melting points and the intramolecular interaction was discussed in this literature. In addition, The vibrational band assignments have been accomplished using a combination of experimental infrared spectra compared with results obtained from DFT calculations in this Literature. All in all, the chemical theory,computer simulations and experiment are comblned to investigatethe interaction relationship cin the Ils. The frame of studing on interaction in ionic liquid is established to successfully reveal the structures an established to sueeessfully reveal the structures ande interactions in the systems. The calculated result shows the probability of designing ILs with the help of theoretical way in the future exploitation.