266nm激光下硝基苯的多光子电离解离研究

在266nm波长激光下,通过激光质谱仪获得气相硝基苯的共振增强多光子电离/飞行时间质谱（REMPI-TOFMS）。根据质谱图中出现的主要离子峰信息,对硝基苯的光解离过程进行了分析。硝基苯与266nm激光的作用过程为三光子过程,其首先吸收两个光子跃迁至激发态,一部分处于激发态的分子,因内转换导致结构重排,生成分子异构体。处于激发态的硝基苯分子或分子异构体共振吸收一光子后发生解离,并给出其可能的解离通道。

Study on multiphoton ionization and dissociation of nitrobenzene at 266 nm

The processes of resonance enhanced multiphoton ionization and dissociation of nitrobenzene are studied with the laser mass spectrometer at 266 nm.The time of flight mass spectra of nitrobenzene is obtained.The dynamic yielding of fragment ions is discussed based on the mass spectra.It is shown that nitrobenzene molecules are firstly two-photons resonantly excited from ground state to excited state and isomerization is found in the course of internal conversion.The excited nitrobenzene molecules and isomers decompose into fragments when they absorb another one photon.The possible dissociation pathways are proposed.