气相CBr2 自由基的产生及激光诱导荧光色散谱研究
The Production and Dispersed Laser Induced Fluorescence Spectrum of Dibromocarbene in Gas Phase
-
摘要: 利用双层流动反应管作为束源,研究了F与CH2Br2反应生成的CBr2和Br2的气相激光诱导荧光色散谱,将得到的谱线分别指定为CBr2的(0,13,0)→(0,v2″,0)(v2″=1~6)跃迁和Br2的 3Π+u→ 1Σ+g跃迁,从光谱中首次得到气相CBr2自由基基态弯曲振动频率ν2″=215 cm-1,实验确认了CBr2自由基和Br2是F+CH2Br2过程多步反应的产物.Abstract: Dispersed laser induced fluorescence spectra of gas-phase CBr2 and Br2 produced by the reaction of F atom with CH2Br2 in the microwave discharge flow tube apparatus have been measured. The dispersed fluorescence spectrum excited at 571.9 nm was assigned to A(0,13,0)→X(0,v2",0)( v2"=16)transitions of CBr2,the fundamental vibrational frequencies of bending mode of gas - phase CBr2 in electronic ground state was firstly derived from the spectrum to be v2"=215 cm-1 . The dispersed fluorescence spectrum excited at 575. 3 nm was assigned to B3Π+u →X1Σ+g transitions of Br2 . The generation of CBr2 and Br2 species is believed to be the second or third step reaction of F atom with CH2Br2 .