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利用飞行时间质谱技术得到了氟利昂F1110(C_2Cl_4)在400nm飞秒脉冲激光作用下的飞行时间质谱图,发现了C_2Cl_4~+、C_2Cl_3~+和C_2Cl_2~+这三种主要的碎片离子。利用密度泛函理论在B3LYP/6-311G++(d,p)基组水平上进一步计算和分析了C_2Cl_4~+在光解离过程中解离通道的能量变化,得出C_2Cl_4~+在光解离过程中需要吸收能量,说明C_2Cl_4~+在大气层中比较稳定。与已有实验得到的C_2Cl_4在800nm飞秒脉冲激光作用下的质谱图进行比较,并通过计算碎片峰中各主要离子的比例以及氯同位素的丰度比发现,C_2Cl_4在红外光辐射下更易发生解离。采用同样的基组对C_2Cl_4和C_2Cl_4~+中的C—Cl键进行势能面扫描,得到其鞍点,发现当C_2Cl_4解离生成C_2Cl_4~+时,C—Cl键的活性变高,更易断键解离。计算和分析了C_2Cl_4~+的红外光谱和拉曼光谱,利用从头算CIS方法得到了C_2Cl_4~+的紫外可见吸收光谱。
The time-of-flight mass spectra of freon F1110 (C_2Cl_4) irradiated by 400nm femtosecond laser were obtained by using time-of-flight mass spectrometry. Three main fragment ions of C_2Cl_4 ~ +, C_2Cl_3 ~ + and C_2Cl_2 ~ + were found. The energy of the dissociation channel of C_2Cl_4 ~ + during photodissociation was further calculated and analyzed at the B3LYP / 6-311G ++ (d, p) basis by density functional theory. It was found that the photolysis of C_2Cl_4 + The process needs to absorb energy, indicating that C_2Cl_4 ~ + is relatively stable in the atmosphere. It is found that C_2Cl_4 is more susceptible to IR in the presence of C_2Cl_4 at 800 nm compared with the mass spectra of C_2Cl_4 pulsed laser at 800 nm. from. Using the same basis set to scan C-Cl bonds in C 2 Cl 4 and C 2 Cl 4+, the saddle points were obtained. It was found that when C 2 Cl 4 dissociated to C 2 Cl 4+, the activity of C-Cl bonds became higher, from. The infrared spectra and Raman spectra of C_2Cl_4 ~ + were calculated and analyzed. The UV-Vis absorption spectra of C_2Cl_4 ~ + were obtained by ab initio CIS method.