物理化学学报 >> 1996, Vol. 12 >> Issue (11): 981-985.doi: 10.3866/PKU.WHXB19961105

研究论文 上一篇    下一篇

甲胺分子多光子电离质谱研究

柳晓军,张冰,方黎,郭文跃,周金刚,蔡继业,路轶群,周士康   

  1. 中国科学院安徽光学精密机械研究所激光光谱开放实验室,合肥 230031
  • 收稿日期:1996-05-10 修回日期:1996-07-10 发布日期:1996-11-15
  • 通讯作者: 柳晓军

Study of the Multiphoton Ionization Mass Spectra of Methylamine

 Liu Xiao-Jun,Zhang Bing,Fang Li,Guo Wen-Yue,Zhou Jin-Gang,Cai Ji-Ye,Lu Yi-Qun,Zhou Shi-Kang   

  1. Laser Spectroscopy Laboratory,Anhui Institute of Optics and Fine Mechanics,Academia Sinica,Hefei 230031
  • Received:1996-05-10 Revised:1996-07-10 Published:1996-11-15
  • Contact: Liu Xiao-Jun

摘要:

用多光子电离飞行时间质谱法,利用可调谐脉冲激光器,测得了甲胺分子在不同激光波长和激光功率下的多光子电离和解离产物,主要产物(CH3NH2+、CH2NH2+、CHNH2+、CH2NH+、CHNH+)经历了一个2+2共振多光子电离过程,CH2NH2+离子源于母体离子CH3NH2+的离解,CHNH2+(CH2NH+)和CHNH+离子则归因于CH2NH2+离子的进一步离解. 母体离子CH3NH2+的离解速率常数随激发波长的增大而减小。

关键词: 甲铵, 多光子电离, 飞行时间质谱

Abstract:

Multiphoton ionization-dissociation process of Methylamine Molecules is studied using Time-Of-Flight mass spectrometer with a pulsed dye laser. Four ion peaks observed under different laser wavelength and laser power are assigned to CH3NH2+、CH2NH2+、 CHNH2+ (CH2NH+) and CHNH+. Based on the experimental results, the Multiphoton lonization and Dissociation(MPID) mechanism of CH3NH2 are discribed:CH3NH2 molecule is ionized to generate CH3NH2+ via 2+2 photon(two photon resonant excitation and two photon ionization)process. CH3NH2+ dissociate to produce CH2NH2+. CHNH2+(CH2NH+) and CHNH+ are generated by the consequent dissociation of CH2NH2+. The experimental results indicate that the dissociation rate constant of CH3NH2+ decreases as laser wavelength increases.

Key words: Methylamine, Multiphoton ionization and dissociation(MPID), Time-of-flight mass spectrometer(TOF-MS)