量子电子学报 ›› 2018, Vol. 35 ›› Issue (5): 513-522.

• 光谱 •    下一篇

羟基丙酮的真空紫外光电离解离

费维飞, 王 明, 陈 军, 李照辉, 余业鹏,林 烜, 刘付轶, 单晓斌, 盛六四   

  1. 中国科学技术大学国家同步辐射实验室, 安徽 合肥 230029
  • 收稿日期:2017-05-04 修回日期:2017-06-18 出版日期:2018-09-28 发布日期:2018-09-29
  • 通讯作者: 刘付轶 (1964-),安徽天长人,高级工程师,硕士生导师,主要从事自由基反应动力学方面的研究。 E-mail:fyliu@ustc.edu.cn
  • 作者简介:费维飞(1991-),安徽肥东人,研究生,主要从事小分子光电离解离质谱方面的研究。
  • 基金资助:

    Supported by National Natural Science Foundation of China(国家自然科学基金,91544105,41275127,U1532137,U1232209,U1232130,11575178

Vacuum ultraviolet ionization and dissociation of hydroxyacetone

FEI Weifei, WANG Ming, CHEN Jun, LI Zhaohui, YU Yepeng, LIN Xuan, LIU Fuyi, SHAN Xiaobin, SHENG Liusi   

  1. National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China
  • Received:2017-05-04 Revised:2017-06-18 Published:2018-09-28 Online:2018-09-29

摘要:

利用真空紫外同步辐射、反射式飞行时间质谱(PI-TOF-MS)和量子化学计算方法研究了气相羟基丙酮(HA)的光电离解离通道。通过测定9.5~15.5 eV光子能量下的光电离效率(PIE)曲线获得了HA的电离能(IE)(9.78 ± 0.06 eV)以及主要碎片离子(C3H5O2+,C3H5O+,C2H5O+,C2H4O+,CH3CO+,CH2OH+,COH+,C2H3+和CH3+)的出现势(AEs)。使用G3B3//B3LYP/6-311++G(d, p)组合方法进行量化计算,得到了与该分子解离过程中相关的反应物、过渡态、中间体及产物的最优结构和单点能。根据实验测得的离子出现势并结合量化计算,分析了羟基丙酮的光电离解离通道及机理。研究结果表明结构重排及分子离子内部氢原子转移在羟基丙酮的光电离解离的过程中起到非常重要的作用。

关键词: 羟基丙酮, 光电离质谱, 光电离解离, 电离能, 出现势, 量子化学计算

Abstract:

The photoionization and dissociative channels of gas-phase hydroxyacetone(HA) are investigated by using vacuum ultraviolet synchrotron radiation, photoionization reflectron time-of-flight mass spectrometer (PI-TOF-MS) and quantum chemistry calculation methods. The ionization energy (IE) of HA, (9.78 ± 0.06) eV, and the appearance energies (AEs) of the major fragment ions C3H5O2+, C3H5O+, C2H5O+, C2H4O+, CH3CO+, CH2OH+, COH+, C2H3+, CH3+ are obtained by measuring photoionization efficiency (PIE) curves in the photon energy region of 9.5~15.5 eV. Quantitative calculation is carried out by G3B3//B3LYP/6-311++G(d, p) combination method. The reactants, transition states and intermediates related with the molecular dissociation process and the optimal product structure and single point energy are obtained. According to the measured ions appearance potential, the photoionization dissociation channel and mechanism of HA are analyzed combining with quantitative calculation. Results show that the structure rearrangement and molecular ion internal hydrogen atom transfer play an important role in the process of photoionization dissociation of HA.

Key words: hydroxyacetone, photoionization mass spectrometry, dissociative photoionization, ionization energy, appearance energy, quantum chemistry calculation

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