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化学学报
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化学学报 ›› 2002, Vol. 60 ›› Issue (5): 825-829. 上一篇    下一篇

研究论文

二甲胺同步辐射光电离解离机理的质谱研究

胡正发;王振亚;周士康;王娟;盛六四;张允武   

  1. 中国科学院安徽光学精密机械研究所环境光谱学实验室,合肥(230031);中国 科学技术大学,合肥(230026)
  • 发布日期:2002-05-15

Mass Resolved Photoionization and Photodissociation of Dimethylamine with Synchrotron Radiation

Hu Zhengfa;Wang Zhenya;Zhou Shikang;Wang Juan;Sheng Liusi;Zhang Yunwu   

  1. Environment Spectroscopy Laboratory, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences,Hefei(230031);National Synchrotron Radiation Laboratory, University of science and Technology of China,Hefei(230026)
  • Published:2002-05-15

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493

被引次数

20 | 3

利用同步辐射光源，结合飞行时间质谱，在超声射流冷却条件下研究了(CH_3) _2NH(DMA)的光电离解离机理。实验观察到四种主要离子(CH_3)_2NH·~+， CH_3NH~+CH_2，CH_2NH_2~+和CHNH~+，质荷比分别为m/z = 45，44，30和28。四种 离子的出现势（AE）分别为8.26，9.52，11.93和11.27 eV，其中分子电离热IP = （8.26 ± 0.01） eV，计算得到分子离子的生成热Δ_fH~o = 778.55 kJ/mol。 分析表明离子CH_3NH~+CH_2来自母体离子的α去H过程。其他碎片离子由后续逐级 解离去H反应以及脱CH_3通道生成。

关键词: 辐射, 光电离, 飞行时间质谱法, 二甲胺

Photoionization and photodissociation of dimethylamine (DMA), by using synchrotron radiation combining with time of flight-mass spectroscopy (TOF-MS), is performed under supersonic molecular beam. Four main ions of (CH_3)_2NH·~+, CH_3NH~+CH_2, CH_2NH_2~+ and CHNH~+ are observed, at appearance energy (AE) of 8.26, 9.52, 11.93 and 11.27 eV respectively. DMA's IP = 8.26 eV and heat of formation of parent ion Δ_fH~o = 778.55 kJ/mol obtained are in well agreement with recommended values. The photo fragmentation mechanism is also discussed.

Key words: RADIATION, PHOTOIONIZATION, TIME-OFF FLIGHT MASS SPECTROMETRY, DIMETHYLAMINE

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