自合成离子液体及其在有机溶剂中的电导率研究

Synthetic ionic liquids and conductivity in organic solvents

目的研究自合成的离子液体富集室内空气中的酯类化合物的能力。方法采用两步法合成了室温离子液体——1-乙酸甲酯基-3-甲基咪唑双三氟甲基磺酰亚胺([CH2COOCH3MIM]NTf2)和1-对甲基苯甲酸甲酯基-3-甲基咪唑双三氟甲基磺酰亚胺([CH2C6H4COOCH3MIM]NTf2),运用红外光谱(IR)、氢核磁共振光谱(1HNMR)和质谱(MS)对其结构进行了表征,并对这两种离子液体在二甲基亚砜(DMSO)和乙酸乙酯中的电导率随离子液体浓度、温度的变化关系进行了分析。结果光谱分析显示合成了预期的离子液体;离子液体的电导率随着温度的升高和浓度的增大而增大;以DMSO作溶剂时的电导率高于乙酸乙酯作溶剂时的电导率;相同条件下[CH2COOCH3MIM]NTf2较[CH2C6H4COOCH3MIM]NTf2具有更高的电导率。结论自合成的离子液体与酯类溶剂有更强的相互作用,适用于酯类物质的富集。

Objective To explore the synthetic ionic liquids whether or not can enrich the ester compounds in indoor air. Methods The ionic liquids 1-methyl acetate-3-methylimidazolium bis （trifluoromethanesulfonyl） imide （[CH2COOCH3M1M] NTf2） and 1-（4-methyl methyl benzoate）-3-methylimidazo]ium bis （trifluoromethanesulfonyl）imide（[CH2C6H4COOCH3MIM] NTf2） were synthesized by a two-steps method. Their structures were characterized and analyzed by IR, HNMR and MS spectroscopy. And the conductivity in various solvents including DMSO and ethyl acetate was studied at different concentrations and temperatures. Results The spectrum analysis showed that the ionic liquids were qualified. The conductivity of ionic liquids in different solvents increased as the concentration and temperature increased. The conductivity of ionic liquids in DMSO was higher than that in ethyl acetate. The ionic liquid [CH2COOCH3MIM]NTf2 had higher conductivity than [CH2C6H4COOCHaMIM]NTf2 in the same condition. Conclusion The synthetic ionic liquids have stronger interaction with ester solvents, so they are suitable for enriching the ester materials.