CCl_2自由基被无机小分子猝灭的速率常数

Measurements of Quenching Rate Constants of CCl_2( A^1B_1 and a^3B_1) by Some Inorganic Molecules

对ＣＣｌ４／Ａｒ混合气体脉冲直流高压放电产生 ＣＣｌ２自由基，用 ５４１．５２ ｎｍ激光将电子基态 ＣＣｌ２激励到Ａ１Ｂ１（０，４，０）振动能级上．通过检测激发态 ＣＣｌ２时间分辨荧光信号，测得室温下 ＣＣｌ２（Ａ１Ｂ１和 ａ３Ｂ１）被 Ｏ２、Ｎ２、ＮＯ、ＣＯ２、ＣＳ２、Ｈ２Ｏ、ＳＯ２，和ＳＦ６分子猝灭的实验结果．用我们提出的三能级模型分析处理实验数据，获得了ＣＣｌ２（Ａ１Ｂ１）态和 ＣＣｌ２（ａ３Ｂ１）态的碰撞猝灭速率常数 ｋＡ和 ｋａ值．

CCl2 free radicals were produced by dc discharge of CCl4 (in Ar). Ground electronic state CCl2 radi-cal was electronically excited to A1 B1 (0, 4, 0) state with Nd: YAG laser pumped dye laser at 541. 52 nm. Experi-mental quenching data of CCl2 (A1B1 and a 3B1) by O2, N2, NO, CO2, CS2, H2O, SO2 and SF6 were obtained by observing time resolved fluorescence from the excited Cd2 radicals, which showed a superposition of two expo-nential decay components. The state-resolved rate constants kA and ka were first time acquired by analyzing and dealing with these data by using a three-level-model proposed by us.