We have investigated the effect of pressure on imidazolium C-H-O interactions in 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide (EMI(+)TFSA(-))/L64 and EMI(+)TFSA(-)/1,4-dioxane mixtures. The addition of Pluronic L64 to EMI(+)TESA(-) leads to appreciable changes in band frequencies and shapes of the imidazolium C-H stretching bands. A possible explanation is the formation of C-H-O interactions between imidazolium C-H 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(+)TESA(-). In contrast to L64, the oxygen atoms of 1,4-dioxane cannot perturb the local structures of imidazolium C-H groups of EMI(+)TFSA(-) 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-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.
- AGGREGATION BEHAVIOR; TRIBLOCK COPOLYMER; 1-BUTYL-3-METHYLIMIDAZOLIUM HALIDES; AQUEOUS-SOLUTIONS; WATER; ORGANIZATION; TEMPERATURE; CHEMISTRY; DIFFUSION
Jiang, J. C., Li, S-C., Shih, P-M., Hung, T-C., Chang, S-C., Lin, S. H., & Chang, H-C. (2011). A High-Pressure Infrared Spectroscopic Study on the Interaction of Ionic Liquids with PEO-PPO-PEO Block Copolymers and 1,4-Dioxane. Journal of Physical Chemistry B, 115(5), 883-888. https://doi.org/10.1021/jp109600c