Structural change of ionic association in ionic liquid/water mixtures: A high-pressure infrared spectroscopic study

摘要: High-pressure infrared measurements were carried out to observe the microscopic structures of two imidazolium-based ionic liquids, i.e., 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide [EMI+(CF3SO2)2N−, EMI+TFSA−] and bis(fluorosulfonyl)amide [EMI+(FSO2)2N−, EMI+FSA−]. The results obtained at ambient pressure indicate that imidazolium C–H may exist in different forms, isolated network structures. As sample pure EMI+FSA− was compressed, configuration is favored with increasing by debiting form. For EMI+TFSA−/H2O mixtures, peaks split into four bands high pressures. new spectral features approximately 3117 3190 cm−1, being concentration sensitive, can be attributed interactions between water molecules. alkyl absorption exhibits a band 3025 cm−1 under This observation suggests formation certa...