过渡金属离子液体的热化学性质研究BMIC/ZnCl2体系

在干燥的氩气氛中, 于363 K下缓慢混合等摩尔的氯化1-甲基-3-丁基咪唑(BMIC)和高纯无水ZnCl2, 得到了无色透明的离子液体BMIC/ZnCl2. 在298.15 K下, 用具有恒温环境的溶解反应热量计测定了不同浓度离子液体BMIC/ZnCl2在水中的溶解焓, 依据Pitzer方程拟合得到它们的标准摩尔溶解焓ΔsH0m和Pitzer溶解焓参数. 利用标准摩尔溶解焓估算了离子液体的水化焓.

Studies on Thermochemical Properties of Ionic Liquid Based on Transition Metal Ions——System BMIC/ZnCl2

A colorless and transparent ionic liquid BMIC/ZnCl2 was prepared by mixing 1-butyl 3-methylimidazolium chloride(BMIC) and ZnCl2 with a molar ratio of 1:1 at 363.15 K under stirring in a glove box filled with dry argon. The molar dissolution enthalpies, ΔsHm, of BMIC/ZnCl2 in water with various molalities were determined by a solution-reaction isoperibol calorimeter at 298.15 K. In terms of Pitzer electrolyte solution theory, the molar solution enthalpy of BMIC/ZnCl2 at infinite dilution, ΔsH0m, and Pitzer parameters: β(0)LMX, β(1)LMX and CφLMX were obtained, respectively. According to Lecocq's viewpoint, ionic liquid BMIC/ZnCl2 with a molar ratio of 1:1 is a single compound BMIZnCl3. In terms of Glasser's theory and thermodynamic cycle, the standard molar hydration enthalpy of ionic liquid BMIZnCl3, (ΔH0+ +ΔH0-)=-497 kJ/mol, was calculated. The standard molar enthalpies of hydration of individual ions can be obtained from those of electrolytes, provided that the value of one ion is known. The standard molar enthalpies of hydration of cation BMI+ were estimated ΔH0+(BMI+)=-225 kJ/mol in literature so that the standard molar enthalpies of hydration of ZnCl-3 was obtained, that is, ΔH0-(ZnCl-3) =-272 kJ/mol.