中文摘要：

利用飞行时间质谱技术得到了氟利昂F1110（C2Cl4）在400nm飞秒脉冲激光作用下的飞行时间质谱图,发现了C2Cl4^＋、C2Cl3^＋和C2Cl2^＋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C2Cl4^＋在光解离过程中解离通道的能量变化,得出C2Cl4^＋在光解离过程中需要吸收能量,说明C2Cl4^＋在大气层中比较稳定。与已有实验得到的C2Cl4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,C2Cl4在红外光辐射下更易发生解离。采用同样的基组对C2Cl4和C2Cl4^＋中的C-Cl键进行势能面扫描,得到其鞍点,发现当C2Cl4解离生成C2Cl4^＋时,C-Cl键的活性变高,更易断键解离。计算和分析了C2Cl4^＋的红外光谱和拉曼光谱,利用从头算CIS方法得到了C2Cl4^＋的紫外可见吸收光谱。

英文摘要：

Time-of-flight mass spectrum of freon 1110 （C2Cl4） under action of 400 nm femtosecond laser pulse is obtained by time-of-flight mass spectrometry technology. Three major fragment ions,C2Cl4^＋ , C2Cl3^＋ and C2Cl2^＋ are discovered in the mass spectrum. Based on the density functional theory, the energy changes in dissociation channels of Cz C14＋ during photodissociation process are further calculated and analyzed at the basis set of B3LYP/6-311G＋＋ （d, p）. The results show that C2Cl4^＋ needs to absorb energy during photodissociation process, which indicates that C2Cl4^＋ is more stable in the ozone layer. Besides, compared with the mass spectrum of C2Cl4 obtained with 800 nm femtosecond pulse laser which has been experienced by other researchers, and through calculating the proportion of each peak to total peak area and the chlorine isotope abundance ratio of major ions in the mass spectra, it is found that C2Cl4 is more likely to dissociate under infrared light radiation. Moreover, the potential energy surfaces of C2Cl4^＋ and C2Cl4^＋ about C-Cl bond are scanned via the same basis set, and the saddle points are obtained. It is found that the activity of C-Cl bond of C2Cl4^＋ becomes higher and the C-C1 bond is easier to break than that in C2Cl4. Infrared spectrum and Raman spectrum of C2Cl^＋ are calculated and analyzed, and UV-VIS spectrum is obtained with CIS method.