基于胸腺嘧啶的离子液体溶剂体系溶解腺嘌呤的实验教学设计

Experimental teaching design for dissolving adenine in solvents based on thymine-derived ionic liquids

该文设计了基于1-乙基-3-甲基咪唑胸腺嘧啶盐([Emim][Thy])的离子液体溶剂体系溶解腺嘌呤教学实验。将[Emim][Thy]分别与二甲基亚砜(DMSO)和乙二醇(EG)混合获得两类溶剂体系[Emim][Thy]-DMSO和[Emim][Thy]-EG用于溶解腺嘌呤。在25℃时,测定了[Emim][Thy]-DMSO和[Emim][Thy]-EG对腺嘌呤的溶解量,并研究了溶剂中[Emim][Thy]含量对溶解性能的影响。利用核磁共振波谱和红外光谱研究了溶解机理。结果显示,[Emim][Thy]-DMSO对腺嘌呤的溶解量远高于[Emim][Thy]-EG,溶解度随着溶剂中[Emim][Thy]含量的增加逐渐增加。[Emim][Thy]-DMSO中的阴离子[Thy]─易与腺嘌呤形成氢键,从而使[Emim][Thy]-DMSO对腺嘌呤具有较好的溶解能力。[Emim][Thy]-EG体系的EG与[Thy]─具有较强的分子间氢键,使[Thy]─不易与腺嘌呤形成氢键,使得腺嘌呤在[Emim][Thy]-EG中的溶解度较小。此外,还研究了[Emim][Thy]-DMSO体系中[Thy]─与腺嘌呤的分子间氢键作用。该实验属于生命科学与化学的交叉领域,实验现象有趣,有助于拓宽学生视野,提升学生的科学研究能力。

In this work,a teaching experiment was designed on the dissolution of adenine in ionic liquid solvents based on 1-ethyl-3-methylimidazolium thyminate([Emim][Thy]).By mixing[Emim][Thy]with dimethyl sulfoxide(DMSO)and ethylene glycol(EG),two kinds of solvent systems[Emim][Thy]-DMSO and[Emim][Thy]-EG were obtained,respectively,to dissolve adenine.The solubilities of adenine in[Emim][Thy]-DMSO and[Emim][Thy]-EG were measured at 25℃,and the effect of[Emim][Thy]content in the solvent on solubility was studied.The dissolution mechanism was studied using nuclear magnetic resonance(NMR)spectroscopy and infrared(IR)spectroscopy.The results showed that the solubility of adenine in[Emim][Thy]-DMSO was much higher than that in[Emim][Thy]-EG,and the solubility gradually increased with the increase of[Emim][Thy]content in the solvent.The anion[Thy]─in[Emim][Thy]-DMSO can easily form hydrogen bonds with adenine,so that[Emim][Thy]-DMSO exhibited a higher solubility for adenine.EG could form strong intermolecular hydrogen bonds with[Thy]─in[Emim][Thy]-EG system,which made it difficult for[Thy]─to form hydrogen bonds with adenine,resulting in the low solubility of adenine in[Emim][Thy]-EG.In addition,the intermolecular hydrogen bond interactions between[Thy]─and adenine in[Emim][Thy]-DMSO system were also studied.This experiment belongs to the intersection field of life science and chemistry,and the experimental phenomena are interesting,which may be useful to broaden students’horizons and enhance their scientific research capabilities.