Study On Synthesis, Characterization And Application Of N, N'-dialkylimidazolium-based Ionic Liquids

The materials which are liquid state at a room temperature or near the room temperature are named room-temperature ionic liquids (RTILs) or room temperature molten salts. The RTILs is the perfect substitute of conventional solvents owing to its highly conductivity, wide electrochemical widow, neglectable vapor tension and special solubility. The study of RTILs accord with the development of green chemistry, and are paid great attention to by the researchers in world in recent years.At first, we have prepared 1-Butyl-3-methylimidazolium Chloride ([BMIm]Cl) using C4H9Cl and 1-Methylimidazole. Then, From [BMIm]Cl, hydrophilic 1-Butyl-3-methylimidazolium tetrafluoroborate ([BMIm]BF4) andhydrophobic 1-Butyl-3-methy -limidazolium hexafluorophosphate ([BMIm]PF6) have been synthesized byreplacement matathesis reaction. All These compounds have beencharacterized and analyzed by UV, IR, 1H-NMR spectra. At the same time, we have determined the physical properties about the hyagroscpicity, molar conductivity and solubility of the RTILs.The second, in order to improve the synthetical efficiency, the microwave assisted synthesis of [BMIm]Cl have been studied. from the orthogonal experimental result, the pure products have been gained but the yield isn't perfect.In addition, the application of the RTILs ([BMIm]BF4, [BMIm]PF6) in the Beckmann rearrangement have been firstly studied. On the conditions of the reducing the oil of vitriol, the effects of the two RTILs in the Beckmann rearrangement have been reviewed and contrast experiment. The experimental results have shown: when the two RTILs, [BMIm]BF4 and [BMIm]PF6,as the Beckmann rearrangement reaction medium, the reaction selectivity and yield haven't been improved. There is probably because that the RTIL's stability and catalytic behavior have been affected in oil of vitriol environment that the expectant purpose haven't been achieved.The profitable discussion in the report about the synthesis of the RTILs and the application of the RTILs in the Beckmann rearrangement will be helpful to the study of the application of the RTILs in other reaction system.