中国物理B ›› 1998, Vol. 7 ›› Issue (4): 271-276.doi: 10.1088/1004-423X/7/4/004

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MULTIPHOTON IONIZATION MASS SPECTRA OF n-C3H7I AND i-C3H7I AT 532 nm

章莲蒂, 魏杰, 姜芸芸, 方黎, 张树东, 郭文跃, 蔡继业   

  1. Laboratory of Laser Spectroscopy, Anhui Institute of Optics and Fine Mechanics, Academia Sinica, Hefei 230031, China
  • 收稿日期:1997-06-28 修回日期:1997-09-29 出版日期:1998-04-20 发布日期:1998-04-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China.

MULTIPHOTON IONIZATION MASS SPECTRA OF n-C3H7I AND i-C3H7I AT 532 nm

ZHANG LIAN-DI (章莲蒂), WEI JIE (魏杰), JIANG YUN-YUN (姜芸芸), FANG LI (方黎), ZHANG SHU-DONG (张树东), GUO WEN-YUE (郭文跃), CAI JI-YE (蔡继业)   

  1. Laboratory of Laser Spectroscopy, Anhui Institute of Optics and Fine Mechanics, Academia Sinica, Hefei 230031, China
  • Received:1997-06-28 Revised:1997-09-29 Online:1998-04-20 Published:1998-04-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China.

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摘要： Multiphoton Ionization (MP) Mass Spectra of n-C3H7I AND i-C3H7I are obtained using a time-offlight mass spectrometer at 532 nm. No parentions are observed in MPI of both isomers. N-propyl cation dissociates more extensively than isopropyl cation. The C2H+5(M/Z=29) ion is observed instead of C2H+4(M/Z=28) ion in MPI of n-C3H7I, in contrast to i-C3H7I. It is found that parent molecules are first two-photon resonantly excited to A-band, then go through dissociation. Fragment ions are produced by ionization and dissociation of neutral fragments. We present directly the diss ociation pathways of n-propyl cation according to the results proposed by Levine using maximum entropy formalism. Moreover, those of isopropyl cation are discussed in this paper through branching ratio analyses.

Abstract: Multiphoton Ionization (MP) Mass Spectra of n-C3H7I AND i-C3H7I are obtained using a time-offlight mass spectrometer at 532 nm. No parentions are observed in MPI of both isomers. N-propyl cation dissociates more extensively than isopropyl cation. The C2H+5(M/Z=29) ion is observed instead of C2H+4(M/Z=28) ion in MPI of n-C3H7I, in contrast to i-C3H7I. It is found that parent molecules are first two-photon resonantly excited to A-band, then go through dissociation. Fragment ions are produced by ionization and dissociation of neutral fragments. We present directly the diss ociation pathways of n-propyl cation according to the results proposed by Levine using maximum entropy formalism. Moreover, those of isopropyl cation are discussed in this paper through branching ratio analyses.

中图分类号:  (Multiphoton ionization and excitation to highly excited states (e.g., Rydberg states))

  • 33.80.Rv
33.15.Ta (Mass spectra) 33.80.Gj (Diffuse spectra; predissociation, photodissociation)