物理化学学报 >> 2015, Vol. 31 >> Issue (9): 1690-1698.doi: 10.3866/PKU.WHXB201507071

理论与计算化学 上一篇    下一篇

EMIM离子液体离子簇模型的量子化学计算

李巍1,*(),张静2,戚传松1   

  1. 1 北京石油化工学院化学工程学院,北京102617
    2 中国科学院大学材料科学与光电技术学院,北京100049
  • 收稿日期:2015-03-30 发布日期:2015-09-06
  • 通讯作者: 李巍 E-mail:liwei77@bipt.edu.cn
  • 基金资助:
    北京石油化工学院优秀学科带头人培育计划(BIPT-BPOAL-2014)

Quantum Chemistry Calculations of Ion Cluster Models of EMIM Ionic Liquids

Wei. LI1,*(),Jing. ZHANG2,Chuan-Song. QI1   

  1. 1 College of Chemical Engineering, Beijing Institute of Petro-Chemical Technology, Beijing 102617, P. R. China
    2 College of Materials Science and Optoelectronics Technology, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
  • Received:2015-03-30 Published:2015-09-06
  • Contact: Wei. LI E-mail:liwei77@bipt.edu.cn
  • Supported by:
    the Breeding Project of Outstanding Academic Leaders of Beijing Institute of Petro-Chemical Technology, China(BIPT-BPOAL-2014)

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摘要：

以1-乙基-3-甲基咪唑(EMIM)卤化物、氟硼酸盐、三溴化物和二碘溴酸盐、氯铝酸和溴铝酸盐等不同种类EMIM离子液体为研究对象,对多阳离子、多阴离子的离子簇模型进行了量子化学计算研究.首先在B3LYP/6-311++G(d, p)水平上(I使用6-311G(d, p)基组)对{[EMIM]Xn}(n-1)- (X = Cl, Br, I, BF4, AlCl4, AlBr4, Br3, IBrI, FHF; n = 2, 3)和{[EMIM]2Xn'}(n'-2)- (n' = 3, 4, 5)离子簇进行构型优化,并对卤化物和氟硼酸盐进行了振动光谱计算.结果表明所采用理论模型在键长、键角等结构参数及红外振动光谱方面均与实验结果符合较好.同时对不同离子簇模型中阴、阳离子间相互作用能与实验熔点之间的关系进行了研究,发现采用{[EMIM]2Xn'}(n'-2)--模型时EMIM离子液体实验熔点与阴、阳离子间相互作用能之间呈现近线性关系.

关键词: 密度泛函理论, 咪唑离子液体, 相互作用能, 离子簇, 熔点

Abstract:

Different types of 1-ethyl-3-methylimidazolium (EMIM) ionic liquid compounds, including halides, tetrafluoroborate, tribromide, diiodobromate, chloroaluminate, and bromine aluminate, have been investigated using quantum chemical calculations. First, geometry optimizations of the ion systems, including {[EMIM]Xn}(n-1)- (X = Cl, Br, I, BF4, AlCl4, AlBr4, Br3, IBrI, FHF; n = 2, 3) and {[EMIM]2Xn'}(n'-2)- (n' = 3, 4, 5), were performed using the density functional theory (DFT) B3LYP method together with the 6-311++G(d, p) (6-311G(d, p) for I) basis set. The vibrational spectra were also calculated for the EMIM halides and tetrafluoroborate. The obtained structures and vibrational spectra were consistent with experimental results. In addition, a linear correlation between melting point and interaction energy was obtained for the {[EMIM]2Xn'}(n'-2)- models of the compounds studied.

Key words: Density functional theory, Imidazolium ionic liquid, Interaction energy, Ion cluster, Melting point