离子液体[Bmim]Br和[Bmim]PF_6的合成及其物化性质研究

采用超声波辅助法合成离子液体1–丁基–3–甲基咪唑溴盐([Bmim]Br)和1–丁基–3–甲基咪唑六氟磷酸盐([Bmim]PF6),研究了超声处理时间、超声频率和原料物质的量比对[Bmim]Br产率的影响,以及超声处理时间、超声频率和溶剂与[Bmim]Br的质量比对[Bmim]PF6产率的影响.结果表明:超声处理时间、超声频率、原料溴代正丁烷与N–甲基咪唑物质的量比分别为50,min、20,Hz、1.1时,[Bmim]Br产率可达到98.88%;在超声处理时间、超声频率、溶剂与[Bmim]Br的质量比分别为50,min、20,Hz和1.5时,[Bmim]PF6产率可达到86.54%.采用红外光谱、紫外吸收光谱和核磁共振氢谱对[Bmim]Br进行结构表征,同时采用对比法,利用红外光谱、紫外吸收光谱对[Bmim]PF6进行表征,并分别测定了[Bmim]Br和[Bmim]PF6的含水量及其在10~30,℃下的密度和折光率与温度的关系.

Synthesis and Physicochemical Properties of Ionic Liquids [Bmim]Br and [Bmim]PF6

Ionic liquids 1-butyl-3-methylimidazolium bromide（[Bmim]Br）and 1-butyl-3-methylimidazolium hexafluoro-phosphate（[Bmim]PF6）were synthesized by using ultrasonic-assisted method. The factors affecting the productivity of [Bmim]Br including reaction time,frequency,the mole ratio of reactants as well as the productivity of [Bmim]PF6,including reacting time and mass ratio of solvent to [Bmim]Br were systematically investigated. The results show that the yield of [Bmim]Br was 98.88% under the optimal synthetic conditions of reaction time of 50,min,frequency 20,Hz and mole ratio 1.1,and the yield of [Bmim]PF6,was 86.54% with reaction time of 50,min,frequency 20,Hz and mass ratio of solvent to [Bmim]Br 1.5. In addition,the structure of [Bmim]Br was characterized by infrared spectra,UV absorption spectra,and NMR spectra;[Bmim]PF6,was characterized by infrared spectra and UV absorption spectra with antithesis. The contents of water and its corresponding physicochemical properties including density and refractive index between 10,℃and 30,℃were also measured.