【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.更多还原

【Abstract】 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±0.05 eV. The potentials for the appearance of C₂HCl⁺₂, 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.更多还原