四氯乙烯的同步辐射光电离研究

利用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四氯乙烯(C₂Cl₄)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C₂Cl₄的电离势IP(C₂Cl₄) =(9.36±0.05)eV及C₂Cl₄光解离碎片离子C₂Cl₃⁺，C关键词：真空紫外光电离离子出现势电离势四氯乙烯

Photoionization studies of C2Cl4 using synchrotron radiation

The photoionization and photodissociation processes of C₂Cl₄ were investigated under the supersonic molecular beam conditions by using a reflectron-time-of-flight mass spectrometer (TOF-MS) and vacuum ultraviolet (VUV) photons from synchrotron radiation source. The photoionization mass spectrum and the photoionization efficiency (PIE) curves of the parent ion and some fragment ions were measured. The appearance potentials of these ions are obtained from their PIE curves. The formation enthalpies of some major ions and the dissociation energy of C₂Cl₄ have been evaluated from these data. According to the experimental results and the energy calculated by G1 theory, the main possible channels of dissociative photoionization of C₂Cl₄ have been discussed. In the future, we can detect C₂Cl₄ with single photon ionization(SPI)-TOFMS technique using 118.0nm laser radiation. This is based on the mass spectrum obtained at the wavelenth by using synchrotron radiation source.