275327 All-Atom and United-Atom Simulations of Guanidinium-Based Ionic Liquids

Monday, October 29, 2012
Hall B (Convention Center )
Xiaomin Liu1, Xiaochun Zhang1, Xiaoqian Yao1 and Suojiang Zhang2, (1)State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China, (2)Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China

All-atom and United-atom Simulations of Guanidinium-based Ionic Liquids

Xiaomin Liu *, Xiaochun Zhang, Xiaoqian Yao & Suojiang Zhang

State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, 100190 Beijing, China

*Corresponding author (email: xmliu@home.ipe.ac.cn)

Ionic liquids (ILs) have been widely used in separation, catalysis, electrochemistry and etc., and one of the most outstanding characters is that ILs can be tailored and tuned for specific tasks. In order to design and make better use of ionic liquids, the structures and properties relationship is indispensable. Both molecular dynamics and Monte Carlo simulations have been proved to be useful tools to understand the behavior of molecules at the microscale and the thermodynamics properties of the system. However, the quality of such simulations depends on the force field parameters describing the interactions between atoms. All-atom (AA) or united-atom (UA) force fields will be used due to the demand for more exact results or the lower computational cost. In order to make an systematic comparison between the two force fields, molecular simulations for four kinds of acyclic guanidinium-based ionic liquids (cations: (R2N)2C=N+<, anion: nitric or perchloric acid ) were performed based on the AA and the UA force fields in this work. AA force field parameters were derived from our previous work [1], and the UA parameters were proposed in this work. Molecular dynamics simulation results using the AA and UA force fields were compared. The simulated densities are very similar to each other. Center of mass radial distribution functions (RDFs), site to site RDFs and spatial distribution functions (SDFs) were also investigated to depict the microscopic structures of the ILs.

 

Reference:

[1] X. Liu, G. Zhou, S. Zhang. Molecular dynamics simulation of acyclic guanidinium-based ionic liquids. Fluid Phase Equilib., 2008, 272: 1-7.

Acknowledgments

This work was supported by General Program Youth of National Natural Science Foundation of China (20903098, 21106146) and State Key Laboratory of Multiphase Complex Systems (MPCS-2011-D-05)


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