三氯乙烯的真空紫外同步辐射光电离和光解离  

Vacuum ultraviolet photoionization and photodissociation of C_2HCl_3 by synchrotron radiation

作　　者：马靖[1] 丁蕾[1] 顾学军[1] 方黎[1] 张为俊[1] 卫立夏[2] 王晶[2] 杨斌[2] 黄超群[2] 齐飞[2] 

机构地区：[1]中国科学院安徽光学精密机械研究所环境光谱学研究室,合肥230031 [2]中国科学技术大学国家同步辐射实验室,合肥230029

出　　处：《物理学报》2006年第6期2708-2713,共6页Acta Physica Sinica

基　　金：中国科学院创新方向性项目(批准号:KJCX2-SW-H08)资助的课题

摘　　要：利用真空紫外(VUV)同步辐射光源和反射式飞行时间质谱仪,在超声冷却条件下对三氯乙烯(C2HCl3)进行了光电离研究,通过测量各离子的光电离效率(PIE)曲线,得到了C2HCl3的电离势PI(C2HCl3)=9·51±0·05eV,以及C2HCl3光解离碎片离子的出现势(PA):PA(C2HCl2+)=12·40±0·05eV,PA(C2HCl+)=15·88±0·05eV和PA(CCl+)=18·33±0·0eV.根据实验和理论计算的结果,分析了可能的解离通道,并结合相关文献所给的热力学数据,推导出主要离子的标准生成焓及母体离子的解离能.实验获得了118.0nm同步辐射光电离下C2HCl3的质谱图,这为以后采用该波长的激光实现C2HCl3的快速探测提供了实验数据.The photoionization and photodissociation of C2HCl3 by vacuum ultraviolet （VUV） photons from synchrotron radiation source were investigated under the supersonic beam conditions by using a reflectron-time-of-flight mass spectrometer （TOF-MS） . The photoionization mass spectrum and the photoionization efficiency （PIE） curves of the parent ion and some fragment ions were measured. The ionization energy of C2HCl3 was measured to be 9.51±1= 0.05 eV. The potentials for the appearance of C2HCl2^＋ , C2HCl^＋ , and CCl^＋ are obtained to be 12.40 ±0.05, 15.88 ± 0.05, and 18.33 ± 0.05, respectively. The formation enthalpies of some major ions and the dissociation energy （DE） of C2HCl3 have been evaluated from these data. According to the experimental results and the theoretical calculations by G1 theory, the main possible channels of dissociative photoionization of C2HCl3 have been discussed. In the future, one can detect C2HCl3 with SPI-TOFMS technique using 118.0nm laser. Based on the mass spectrum obtained at that wavelength using synchrotron radiation source.

关 键 词：同步辐射光电离 电离势 出现势 三氯乙烯 

分 类 号：O432.1[机械工程—光学工程]