文摘
We have investigated the effect of pressure on imidazolium C鈭扝---O interactions in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide (EMI+TFSA鈭?/sup>)/L64 and EMI+TFSA鈭?/sup>/1,4-dioxane mixtures. The addition of Pluronic L64 to EMI+TFSA鈭?/sup> leads to appreciable changes in band frequencies and shapes of the imidazolium C鈭扝 stretching bands. A possible explanation is the formation of C鈭扝---O interactions between imidazolium C鈭扝 groups and oxygen atoms of polyethylene oxides (PEOs). In other words, L64 can be added to change the relative contribution of the isolated and associated components of EMI+TFSA鈭?/sup>. In contrast to L64, the oxygen atoms of 1,4-dioxane cannot perturb the local structures of imidazolium C鈭扝 groups of EMI+TFSA鈭?/sup> and the association configuration is still favored in the presence of 1,4-dioxane. As the pressure is elevated, 1,4-dioxane molecules tend to associate with themselves and TFSA鈭?/sup> interacts with EMI+ to form associated configurations. Our results suggest the formation of association between EMI+ cation and L64 and the complexes are stable up to the pressure of 2.5 GPa.