COSMO-SAC模型和密度泛函理论在萃取分离剂分子设计中的应用比较研究

基于离子液体的结构可设计性，通过计算机辅助的方式可以设计出具有高萃取效果的离子液体萃取分离剂。通常使用的是COSMO-SC模型和密度泛函理论，两种方法均具有各自的优点。然而，本文发现对于同一待分离体系COSMO-SAC模型和密度泛函理论所预测的萃取效率排序存在不同。针对这一问题，本文以离子液体萃取脱硫为例通过COSMO-SAC模型筛选出具有高分离效率的六种离子液体，同时使用密度泛函理论在机理的角度上获得了六种离子液体的分离效率，发现两种方法的分离效率确实存在不一致。通过实验并利用高效液相色谱对分离后的含硫化合物进行浓度测定，实验结果表明，六种离子液体的分离效率与密度泛函理论的结果是一致的。最终，在计算原理的角度上说明了两种模型计算结果存在差异的原因。

The study of comparison between COSMO-SAC model and DFT quantum chemical model in separation agents molecular design

Recently we founded COSMO-SAC model and density functional theory (DFT) have some inconsistencies in prediction of the efficiency of extraction separation. Searching ILs agents for desulfurization by using two models was studied on this aforementioned issue. Six ILs solvents were determined by COSMO model. Analyzing these six ILs on mechanism level, the order of desulfurization efficiency based on DFT model was obtained. The results show that there are some inconsistencies between two models on the order of desulfurization efficiency. Experiments were carried out to verify the accuracy. Then the reasons of appearing inconsistencies were interpreted at calculation principle aspect.