Photofragment translational spectroscopy of iodobenzene at 266 nm  

作　　者：张宏 朱荣顺 王光俊 孙巨龙 韩克利 何国钟 楼南泉 

出　　处：《Science China Chemistry》1999年第3期305-310,共6页中国科学（化学英文版）

基　　金：Project supported by the National Natural Science Foundation of China;the Youth Fund of Dalian Institute of Chemical Physics;the Chinese Academy of Sciences

摘　　要：The photofragmentation of C6H5] at 266 nm is investigated on the nuiversal crossed molecular beam ma-chine, and the translational spectroscopy as well as the angular distribution of I atom is measured. The results reveal that under the laser intensity of 108 W/cm2 the single-photon dissociation competes with multi-photon processes. In singlephoton dissociation the anisotropy parameter β is 0.4 and the average translational energy is only 1.04 kcal/mol, which indicates that this process is a slow predissociation. In two-photon photofragmentation the average translational energy is 51.64 kcal/mol, which accounts for about 35% of the available energy. Another photofragmentation channel is even more faster, whose peak in time-of-flight spectra corresponds to four or five photon absorptions. The branching ratio of these three channels is determined to be about 3:3:4.The photofragmentation of C₆ H₅I at 266 nm is investigated on the nuiversal crossed molecular beam machine, and the translational spectroseopy as well as the angular distribution of I atom is measured. The results reveal that under the laser intensity of 10⁸ W/cm² the single-phuton dissociation competes with multi-photon processes. In singlephoton dissociation the anisotropy parameter β is 0.4 and the average translational energy is only 1.04 keal/mol, which indicates that this process is a slow predissociation. In two-photon phutofragmentation the average translational energy is 51.64 kcal/mol, which accounts for about 35% of the available energy. Another photofragmentation channel is even more faster, whose peak in time-of-flight spectra corresponds to four or five photon absorptions. The branching ratio of these three channels is determined to be about 3: 3: 4.

关 键 词：UNIVERSAL CROSSED molecular beam machine ANGULAR DISTRIBUTION TRANSLATIONAL energy distribution. 

分 类 号：O657.3[理学—分析化学]