五种新合成酯基取代的咪唑类离子液体电导率的测定与分析

Determination and analysis of conductivity of five synthetic ester-substituted imidazole ionic liquids

离子液体的电导率性质反映了离子液体的导电性能,与溶剂中的电离度以及离子的溶剂化能力密切相关。为了研究本实验室合成的5种酯基取代的离子液体的电导率,用DDS307电导率仪测定1-乙酸甲酯基-3-甲基咪唑双三氟甲基磺酰亚胺([MIMCH2COOCH3]NTf2)、1-乙酸乙酯基-3-甲基咪唑双三氟甲基磺酰亚胺([MIMCH2COOCH2CH3]NTf2)、1-乙酸正丙酯基-3-甲基咪唑双三氟甲基磺酰亚胺([MIMCH2COOCH2CH2CH3]NTf2)、1-对甲基苯甲酸甲酯基-3-甲基咪唑双三氟甲基磺酰亚胺([MIMCH2C6H4COOCH3]NTf2)和1-对甲基苯甲酸乙酯基-3-甲基咪唑双三氟甲基磺酰亚胺([MIMCH2C6H4COOCH2CH3]NTf2)在二甲基亚砜、甲醇、乙腈和乙酸乙酯中的电导率数据。结果表明,其他条件不变时,在一定浓度范围内,离子液体的电导率随着其浓度的增大而增大;在一定温度范围内,随着温度的升高,离子液体电导率增大;4种溶剂相比电导率从小到大顺序依次为乙酸乙酯、二甲基亚砜、甲醇、乙腈,反映了带酯基的5种离子液体与乙酸乙酯的相互作用。

The conductivity properties of ionic liquids reflects the conductive capacity of ionic liquids,which is closely related to the degree of ionization in the solvents and the ability of ion solvation.In order to study the conductivity of five synthetic ester-substituted imidazole ionic liquid which were synthesized by our lab,we used the DDS307 conductivity meter to determine the conductivities of [MIMCH2COOCH3 ] NTf2,[MIMCH2COOCH2CH3]NTf2,[MIMCH2COOCH2CH2CH3]NTf2,[MIMCH2C6H4COOCH3]NTf2and[MIMCH2C6H4COOCH2CH3]NTf2in the solvents of methanol,acetonitrile,DMSO,ethyl acetate,respectively.The results shown that within a certain concentration range,the conductivity of the ionic liquid increased with the increase of the liquid concentration,when other conditions remained the same.Moreover,within a certain temperature range,the conductivity of the ionic liquid increased with the increase of the temperature.Compared between the conductivities of the four solvents,the values of the conductivities ranging from small to large were in the order of ethyl acetate,DMSO,methanol and acetonitrile.Reflects the interaction of five kinds of ester-substituted ionic liquids and the ethyl acetate.