乙醛紫外多光子电离动力学研究

本文报道了在分子束条件下,用XeCl准分子激光多光子电离乙醛的质谱研究结果。碎片离子强度与进气量之间的线性变化关系表明乙醛的多光子电离(MPI)过程是一个单体反应,揭示了乙醛紫外光解的一些性质。由取得的质谱、质谱中碎片离子强度与激光光强之间的变化关系,以及其乙醛第一单重激发态¹(n,π^*)的光物理性质,我们提出了母体分子离解——中性碎片电离模型,根据这个模型,可以解释实验结果。 关键词：

DYNAMICS OF MULTIPHOTON IONIZATION OF ACETALDEHYDE BY UV LASER

In this article, we present the experimental results of mass spectroscopic study of multi-photon ionized acetaldehyde molecules in gaseous phase excited by XeCl excimer laser under the molecular beam condition. Based on the linear relations between the intensities of fragment ions and the pressure of sample gas, we show that the multiphoton ionization and fragmentation of acetaldehyde is an unimolecular reaction, this result reveals some photochemical be havior of acetaldehyde in the photolysis process by uv laser. According to the MPP mass spectrum of acetaldehyde, the variation of the intensities of the fragment ions in the MPI mass spectrum with laser power and photophysical property of its first excited single state ¹(n,π^*), we propose a parent dissociation-neutral fragments ionization model of MPI of acetaldehyde, with which the experimental results can be explained.