低能离子-分子反应动力学的研究进展  

Progresses in the Study of Low-Energy Ion-molecule Reaction Dynamics

作　　者：胡婕 田善喜 Hu Jie;Tian Shanxi(Hefei National Laboratory for Physical Sciences at the Microscale,University of Science and Technology of China,Hefei 230026;Chemical Physics Department,University of Science and Technology of China,Hefei 230026)

机构地区：[1]中国科学技术大学合肥微尺度物质科学国家研究中心,合肥230026 [2]中国科学技术大学化学物理系,合肥230026

出　　处：《化学学报》2022年第4期535-541,共7页Acta Chimica Sinica

基　　金：国家自然科学基金(Nos.22003062,21625301)资助。

摘　　要：离子-分子反应是星际空间、地球大气、燃烧火焰和等离子体等各类环境中物质演化的关键步骤之一,而且此类反应还涉及到电荷转移、能量传递等基本物理化学过程.近十几年来,离子速度成像技术的引入推动了低能离子-分子反应动力学的实验研究,但仍有很多微观动力学机制有待深入探索.基于自制的交叉束离子速度成像装置,本研究组最近利用延迟线阳极探测器实现了多通道产物的三维离子速度影像的高效测量.对Ar^(+)和小分子的电荷转移研究中,作者发现了此过程与光电离、Marcus理论模型之间的差异;通过研究Ar^(+)与O_(2)、CO的解离性电荷转移反应,揭示了奇特的立体动力学特征,分析了解离性电荷转移与纯电荷转移的动力学差异.结合国际上相关研究,作者对未来的实验技术发展与研究内容作了展望.Ion-molecule reaction is one of the most fundamental processes in the Earth and other planets’atmosphere,interstellar space and combustion.Basic physical chemistry processes such as charge transfer and energy transfer are frequently involved in the low-energy(several e V)ion-molecule reactions.In recent decades,the experimental study of low-energy ion-molecule reaction dynamics is highly benefit from the introduction of velocity map imaging method,but some dynamics mechanisms remain to be validated.Based on our own cross-beam ion velocity imaging apparatus,we have recently realized an efficient measurement of three-dimensional ion velocity images for multiple products by using a delay line anode detector,indicating the much higher efficiency.Upon above technique improvement,more details about the charge transfer reactions between Ar^(+)and small molecules have been revealed.Here we summarize and emphasize the dynamics differences among this process,photoionization and Marcus theoretical model.Meanwhile,we obtained stereodynamic characteristics of the dissociative charge transfer reactions of Ar^(+)with O_(2)and CO.Moreover,comparison between the charge transfer only and dissociative charge transfer reaction indicates that the latter is not a subsequent even of the former,namely,these two processes may have completely different pathways.We also present a perspective about the experimental techniques those are potentially applicable and some interesting topics in the future.

关 键 词：离子-分子反应 交叉束 离子速度成像 电荷转移 解离电荷转移 

分 类 号：O643.1[理学—物理化学]