摘要
The structure of [Bmim]2CuCl4 ionic liquids （Bmim： 1-butyl-3-methylimidazolium） with different ratios of H2O and C2H5OH was investigated using X-ray absorption fine structure （XAFS） technique. In this study, XAFS was employed to directly probe the conformational variations of copper ions in [Bmim]2CuCl4 with the addition of either water or ethanol. XAFS analysis confirmed that the structure of ionic liquids gradually transformed from tetrahedral to octahedral configuration with the increase in ratio of H2O. Our results also showed that water molecules coordinated with the copper ions of [Bmim]2CuCl4, leading to the conformational change in ionic liquids. However, the XAFS spectra of [Bmim]zCuCIa/C2H5OH indicated no coordination of anhydrous ethanol with the copper ions of [Bmim]2CuC14. The structure of [Bmim]2CuCl4 ionic liquids is maintained as the tetrahedral configuration in presence of ethanol. Therefore, anhydrous ethanol causes little variation in the structure of ionic liquids and it is a good solvent for the dilution of ionic liquids.
The structure of [Bmim]2Cu Cl4 ionic liquids(Bmim: 1-butyl-3-methylimidazolium) with different ratios of H2 O and C2H5 OH was investigated using X-ray absorption fine structure(XAFS) technique. In this study, XAFS was employed to directly probe the conformational variations of copper ions in [Bmim]2Cu Cl4 with the addition of either water or ethanol. XAFS analysis confirmed that the structure of ionic liquids gradually transformed from tetrahedral to octahedral configuration with the increase in ratio of H2 O. Our results also showed that water molecules coordinated with the copper ions of [Bmim]2Cu Cl4, leading to the conformational change in ionic liquids. However, the XAFS spectra of [Bmim]2Cu Cl4/C2H5 OH indicated no coordination of anhydrous ethanol with the copper ions of [Bmim]2Cu Cl4. The structure of [Bmim]2Cu Cl4 ionic liquids is maintained as the tetrahedral configuration in presence of ethanol. Therefore, anhydrous ethanol causes little variation in the structure of ionic liquids and it is a good solvent for the dilution of ionic liquids.
基金
supported by the National Natural Science Foundation of China(11079007,21306220)
