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题名	离子液体的量子力学计算和分子动力学模拟研究
作者	于光任
学位类别	博士
答辩日期	2007-06-13
授予单位	中国科学院过程工程研究所
授予地点	过程工程研究所
导师	张锁江
关键词	离子液体 量子力学计算 分子动力学模拟
其他题名	Studies on Ionic Liquids by Using Ab Initio Quantum Mechanics Calculation and Molecular Dynamics Simulation
学位专业	应用化学
中文摘要	为了从微观水平上揭示功能化离子液体的结构-性质关系和建立CO2/SO2捕集分离的理论基础，本文采用量子力学计算（QM）和分子动力学模拟（MD）方法，对功能化离子液体及其复合体系的结构、性质及作用机理进行了系统地研究，主要研究内容和创新性结论如下： （1）采用QM和MD研究了氨基咪唑和氨基酸季鏻盐离子液体的微观结构及相互作用。结果发现：对于氨基咪唑离子液体，除了咪唑环C2、C4和C5作用位外，烷基侧链终端的–NH2是一个新的强作用位，该作用位增强了–NH2对CO2的吸收性能，但也可能是导致离子液体粘度升高的主要因素；对于氨基酸季鏻盐离子液体，阴离子中的供电子性羧酸根使得自由–NH2能够与CO2之间进行有效的前线分子轨道重叠，具有良好的CO2捕集效果，并从分子水平上揭示了氨基酸季鏻盐较氨基咪唑离子液体粘度降低的原因。 （2）采用QM研究了胍类乳酸盐离子液体[tmgH][L]的离子对结构及其捕集CO2/SO2的机理。结果发现，[tmgH]+中心碳原子和–NH2的正电荷具有更加局域化的特征，导致其对CO2捕集能力极弱，但仍对SO2具有良好的捕集效果，其微观机理是在[L]－作用下[tmgH]+中的–NH2与SO2反应形成了氨基亚磺酸结构。进一步研究还发现，[tmgH][L]离子对在气相中可能发生离子间的质子转移生成更加稳定的二聚体、三聚体或四聚体。 （3）采用QM和MD研究了ZnBr2/[mmim][Br]体系的微观结构。结果发现，在{Zn[Br]m[mmim]n}2-m+n离子簇中，Zn2+周围的[Br]－配位数为3~4；当 [mmim][Br]:ZnBr2=2（摩尔比）时，液相中Zn2+主要以ZnBr4或 [ZnYBrX]2Y-X的形式存在，即一个[Br]－被多个Zn2+共享，且Zn2+以饱和配位形式存在。
英文摘要	In order to understand the structure-property relationships of functional ionic liquids (ILs) at a microscopic level and establish a theoretical foundation for capturing CO2/SO2 by ILs, in this work, the structure, properties and function mechanism of functional ILs and IL complex system are systemically studied by using ab initio quantum mechanics (QM) calculations and molecular dynamics (MD) simulations. The details are listed as follows. (1)Structure and interaction in amino-functionalized imidazolium and amino acid phosphonium ILs were studied by using QM calculations and MD simulations. It was found that a) in amino-functionalized imidazolium ILs, besides C2, C4 and C5 on imidazolium ring, terminal –NH2 on alkyl side chain is a new strong anion-cation interaction site, which enhances the absorption ability of –NH2 for CO2, however, possibly results in higher viscosities of such ILs simultaneously; b) in amino acid phosphonium ILs, the –NH2 is free, which partially explains the lower viscosities than that of amino-functionalized imidazolium ILs, and electron-donating carboxylate group in anions makes the frontier molecular orbitals between –NH2 and CO2 effectively overlap which is consistent with the excellent capture ability for CO2. (2)Guanidinium lactate [tmgH][L] ion pair and the function mechanism in CO2/SO2 absorption were studied by using QM calculations. It was found that a) positive charges are more localized on the central C atom and –NH2 of [tmgH]+, which results in the weak capture ability for CO2; b) the excellent capture ability for SO2 results from the microscopic fact that the –NH2 in [tmgH]+ reacts with CO2 to produce aminosulfinate unit with the assistant of [L]－. Another find is that a proton transfer happens in [tmgH][L] gas phase ion pair and form more stable molecular di-, tri- or tetra-polymers. (3)Structure of ZnBr2/[mmim][Br] system was studied by using QM calculations and MD simulations. It was found that a) in {Zn[Br]m[mmim]n}2-m+n ion clusters, Zn2+ is coordinated by 3~4 [Br]－ ligands; b) in the liquid phase where the molar ratio of [mmim][Br]:ZnBr2 is 2, Zn2+ exists in the term of ZnBr4 or [ZnYBrX]2Y-X network-unit where [Br]－ is shared by many Zn2+ with a full coordination.
语种	中文
公开日期	2013-09-13
页码	147
内容类型	学位论文
源URL	[http://ir.ipe.ac.cn/handle/122111/1054]
专题	过程工程研究所_研究所（批量导入）
推荐引用方式 GB/T 7714	于光任. 离子液体的量子力学计算和分子动力学模拟研究[D]. 过程工程研究所. 中国科学院过程工程研究所. 2007.

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