离子液中溶剂化电子的结构及其演化动力学  

Structures and Time-Evolution Dynamics of Solvated Electron in Ionic Liquids

作　　者：步宇翔[1] 

机构地区：[1]山东大学化学与化工学院理论化学研究所,济南250100

出　　处：《化学进展》2012年第6期1094-1104,共11页Progress in Chemistry

基　　金：国家自然科学基金项目(No.20633060;20973101);教育部新世纪优秀人才支持计划;山东大学自主创新基金项目(No.2009JC020)资助

摘　　要：本文综述了离子型液体介质中过剩电子的结构、存在状态及其时间演化动力学特征。基于从头算分子动力学模拟及计算结果,重点阐述了咪唑型、吡啶型、碱金属离子型熔盐氯化物离子液中与过剩电子溶剂化密切相关的溶剂化能量学、结构特征、可能的存在状态以及态-态转化稳态动力学机制,分析了此类离子型介质中电子高效传导的内在本质及离子液组成离子的重要作用。阳离子的最低未占轨道组成的导带结构是离子液中过剩电子的溶剂化态及其稳定性的决定因素,任何能影响或改变其导带结构的因素均能显著影响过剩电子溶剂化。但快速的态-态转化及电子迁移并不明显取决于其组成离子扩散动力学,而是敏感地受离子液涨落所控制。这种基于溶剂化电子的迁移模式构成了此类离子型介质甚至其他液态介质中电子转移的新途径。Structures,states and time-evolution dynamics of excess electron in ionic liquid media are surveyed.On the basis of the ab initio calculations and molecular dynamics simulations,we discussed the solvation energetics,structural characters,possible existing states and state-to-state conversion mechanisms associated with solvation of excess electron in the imidazolium-type,the pyridinium-type,and the quaternary ammonium-type chloride room temperature ionic liquids,and a representative alkali-metal halide molten salt,and analyzed the nature of efficient conduction of electrons in such media and the important role of constituent ions of the ionic liquids.The conduction band structure consisted of the lowest unoccupied molecular orbitals of the cations is a decisive factor in determining the solvated states and stability of the excess electron in ionic liquids,and any factors which affect or change the conduction band structure do considerably affect solvation of excess electron in ionic liquids.However,the rapid state-to-state conversion dynamics and electron migration do not sensitively depend on the diffusion dynamics of the constituent ions,but are controlled by ionic liquid fluctuation.This kind of solvated-electron-based electron migration mechanism provides a new electron transfer pathway in such ionic media or other liquid media.

关 键 词：溶剂化电子 离子液 定域态 弥散态 电子稳态演化动力学 

分 类 号：O641.121[理学—物理化学] O643.1[理学—化学]