三氯乙烯的真空紫外同步辐射光电离和光解离

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P_I(C₂HCl₃)=9.51±0.05eV，以及C₂HCl₃光解离碎片离子的出现势(P_A)：P_{关键词： 同步辐射光电离 电离势 出现势 三氯乙烯}

Vacuum ultraviolet photoionization and photodissociation of C2HCl3 by synchrotron radiation

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.