New force field for molecular simulation of guanidinium-based ionic liquids.
New force field for molecular simulation of guanidinium-based ionic liquids.
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DOI：
10.1021/jp060834p
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发表时间：
2006-06
期刊：
影响因子：
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通讯作者：
Xiaomin Liu;Suojiang Zhang;Guohui Zhou;Guangwen Wu;Xiaoliang Yuan;X. Yao
中科院分区：
文献类型：
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作者：
Xiaomin Liu;Suojiang Zhang;Guohui Zhou;Guangwen Wu;Xiaoliang Yuan;X. Yao
提出了一种新的室温离子液体N，N‘，N’-四甲基胍(TMG)离子液体的全原子力场。该模型基于琥珀力场，并对几个参数进行了修改。改进包括：(1)根据从头计算和(或)实验获得的数据，对获得键力系数和角度的振动频率进行拟合；(2)根据从头计算得到的数据，对二面角的扭转能分布进行拟合，以获得扭转参数。为了验证力场的有效性，对5种RTIL进行了不同温度下的分子动力学模拟，其中TMG为阳离子，甲酸盐、乳酸盐、高氯酸盐、三氟乙酸酯和三氟甲基磺酸为阴离子。预测的密度与实验数据吻合较好。用径向分布函数(RDF)和空间分布函数(SDF)描述了RTIL的微观结构。
An all-atom force field was proposed for a new class of room temperature ionic liquids (RTILs), N,N,N',N'-tetramethylguanidinium (TMG) RTILs. The model is based on the AMBER force field with modifications on several parameters. The refinements include (1) fitting the vibration frequencies for obtaining force coefficients of bonds and angles against the data obtained by ab initio calculations and/or by experiments and (2) fitting the torsion energy profiles of dihedral angles for obtaining torsion parameters against the data obtained by ab initio calculations. To validate the force field, molecular dynamics (MD) simulations at different temperatures were performed for five kinds of RTILs, where TMG acts as a cation and formate, lactate, perchlorate, trifluoroacetate, and trifluoromethylsulfonate act as anions. The predicted densities were in good agreement with the experimental data. Radial distribution functions (RDFs) and spatial distribution functions (SDFs) were investigated to depict the microscopic structures of the RTILs.