N-甲基咪唑+甲醇体系的性质及相互作用

Properties and molecular interactions of N-methylimidazole with methanol

测定咪唑基离子液体前驱体N-甲基咪唑在293.15K时与甲醇构成的二元体系的密度、黏度和折光率,计算体系的黏滞性活化吉布斯自由能、超额摩尔体积、黏度偏差和折光率偏差.用四参数多项式描述体系的密度、黏度、折光率和黏滞性活化吉布斯自由能与N-甲基咪唑的摩尔分数的关系.体系超额体积、黏度偏差及折光偏差用Redlich-Kister方程进行关联.结果表明,3种偏差性质均显示N-甲基咪唑与甲醇分子间存在较强的相互吸引作用,并且在N-甲基咪唑摩尔分数x在0.4～0.5范围内,相互作用效果达到最大.通过改变甲醇的含量,不但可以使其作为反应溶剂,也可以作为反应后除掉N-甲基咪唑的溶剂.

Density, viscosity and refractive index for binary mixtures of N-methylimidazole with methanol at 293.15K and over the full molar fraction range were measured. Gibbs energy of ac- tivation of viscous flow, excess molar volume, viscosity and refractive index deviations were calculated from these properties data. As a function of the molar fraction of N-methylimid- azole, the density, viscosity, refractive index and Gibbs energy of activation of viscous flow were correlated by a third-order polynomial equation. As a function of the molar fraction of N- methylimidazole, the excess molar volume, viscosity and refractive index deviations were fitted to the third-order Redlich-Kister polynomial. It shows that there exists strong interaction between N-methylimidazole and methanol from the three deviation properties about x≈0. 440. 5, the maximum interaction effect. It can be concluded that by changing the content, methanol can be made as reaction solvent,and also be used as the removal of N-methyl imidazole solvents af- ter reactions.