摘要
本文利用同步辐射真空紫外和超声分子束反射式飞行时间质谱系统研究间二甲苯的光电离和离解光电离.通过测定母体离子C_(8)H_(10)^(+)和主要碎片离子(C_(8)H_(9)^(+)和C_(7)H_(7)^(+))的光电离效率谱,确定了母体分子的电离能和主要碎片离子(C_(8)H_(8)^(+)和C_(7)H_(7)^(+))的出现势分别为8.60±0.03 eV,11.76±0.04 eV和11.85±0.05 eV eV.在B3LYP/6-311++G(d,p)水平上优化了两个主要解离通道的反应物、过渡态、中间体和产物的结构,并在G3水平上计算了它们的能量,以及两个主要的离解光电离通道产物C_(7)H_(7)^(+)+CH_(3)和C_(8)H_(9)^(+)+H的能量.结合理论和实验结果,间二甲苯的离解光电离机理主要过程是C-H键或C-C键的离解和氢迁移.
The photoionization and dissociative photoionization of m-xylene(C8H10)were researched by using synchrotron radiation vacuum ultraviolet(SR-VUV)and supersonic expanding molecular beam reflectron time-of-flight mass spectrometer(RFTOF-MS)system.The photoionization efficiency spectra(PIEs)of parent ion C_(8)H_(10)^(+) and main fragment ions C_(8)H_(9)^(+) and C_(7)H_(7)^(+) were observed,and the ionization energy(IE)of m-xylene and appearance energies(AEs)of main fragment ions C_(8)H_(9)^(+) and C_(7)H_(7)^(+) were determined to be 8.60±0.03 eV,11.76±0.04 eV and 11.85±0.05 eV,respectively.Structures of reactant,transition states(TSs),intermediates(INTs),and products involved in two dominant dissociation channels were optimized at the B3LYP/6-311++G(d,p)level,and the relative energies were calculated at the G3 level.Based on the results,two major dissociative photoionization channels,C_(7)H_(7)^(+)+CH_(3)and C_(8)H_(9)^(+)+H were calculated at the B3LYP/6-311++G(d,p)level.On the basis of theoretical and experimental results,the dissociative photoionization mechanisms of m-xylene were proposed.The C–H or C–C bond dissociation and hydrogen migration are the main processes in the dissociation channels of m-xylene cation.
作者
赵玉杰
杨昊航
黄培
李李
靳建辉
陈俞钱
曹小岗
曾奇
杜俊杰
单晓斌
盛六四
Yujie Zhao;Haohang Yang;Pei Huang;Li Li;Jianhui Jin;Yuqian Chen;Xiaogang Cao;Qi Zeng;Junjie Du;Xiaobin Shan;Liusi Sheng(Engineering Research Center of Nuclear Technology Application(East China University of Technology),Ministry of Education,Nanchang 330013,China;School of Nuclear Science and Engineering,East China University of Technology,Nanchang 330013,China;National Synchrotron Radiation Laboratory,School of Nuclear Science and Technology,University of Science and Technology of China,Hefei 230029,China;School of Geophysics and Measurement-Control Technology,East China University of Technology,Nanchang 330013,China;Anhui Nuclear Exploration Technology Central Institute,Wuhu 241002,China)
基金
This work was supported by the National Natural Science Foundation of China(No.11275006,No.12105042,No.11805032,No.11505027,No.11575178,No.U1532137)
Nuclear Technology Application Engineering Research Center Open Foundation of Ministry of Education(No.HJSJYB2015-6,No.HJSJYB2017-1,HJSJYB2018-6)
the Chinese Scholarship Council(No.201608360053)
the Graduate Students High-Quality Course Construction Program of Jiangxi Province(No.JXYYK2016-12)
the China Postdoctoral Science Foundation(No.2013M531530)
the Doctoral Foundation of East China University of Technology(No.DHBK201401,No.DHBK2018059)
the Provincial Natural Science Research Program of Higher Education Institutions of Anhui Province(No.KJ2012B086).
作者简介
Author to whom correspondence should be addressed:Yujie Zhao,E-mail:jackzyj@ustc.edu.cn;Author to whom correspondence should be addressed:Liusi Sheng,lssheng@ustc.edu.cn。
