Acta Phys. -Chim. Sin. ›› 2015, Vol. 31 ›› Issue (9): 1690-1698.doi: 10.3866/PKU.WHXB201507071


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
  • Supported by:
    the Breeding Project of Outstanding Academic Leaders of Beijing Institute of Petro-Chemical Technology, China(BIPT-BPOAL-2014)


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


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