CCl_2(A^1B_1)自由基不同振动态的猝灭动力学  

The Collisional Quenching of CCl_2(A^1B_1) in Different Vibrational States by Quenchers

作　　者：高义德[1] 冉琴[1] 陈旸[1] 陈从香[1] 

机构地区：[1]中国科学院选键化学开放实验室

出　　处：《化学学报》2002年第2期256-260,共5页Acta Chimica Sinica

基　　金：国家自然科学基金 (No.10 0 32 0 5 0 )重点项目 ;国家自然科学基金 (No.2 99730 38)项目;国家重点基础研究专项基金 (No .G19990 75 30 4)资助

摘　　要：对CCl4 /Ar混合气体直流脉冲放电产生CCl2 自由基 ,再分别用波长为 5 5 0 .5 6nm ,5 41.5 2nm ,5 32 .2 5nm ,5 2 4.31nm ,5 2 3.82nm和 5 2 3.2 7nm的激光将电子基态CCl2 激励到激发态A1B1的 (0 ,3,0 ) ,(0 ,4,0 ) ,(1,3,0 ) ,(0 ,6 ,0 ) ,(1,4,0 ) ,(2 ,2 ,0 )振动态 ,激发态CCl2 (A1B1)的不同振动态的时间分辨荧光信号显示该信号呈双指数衰减 .测得室温下CCl2 (A1B1)不同振动态被NH3 ,H2 O ,CH2 Br2 ,NH(CH3 ) 2 ,NH(C2 H5) 2 ,N(C2 H5) 3 ,n C6H14 等分子猝灭的实验结果 ,用三能级模型分析处理实验数据 ,获得态分辨速率常数kA 和ka 值 ,并对实验结果进行了讨论 .CCl2 free radicals were produced by D.C. discharge of CCl4 (in Ar). Ground electronic state CCl2 radical was electronically excited to A(1)B(1)(0,3,0), (0,4,0), (1,3,0), (0,6,0), (1,4,0) and (2,2,0) vibronic states by Nd: YAG laser pumped dye laser at the wavelength of 550.56, 541.52, 532.25, 524.31, 523.82 and 523.37 nm, respectively. Experimental quenching rate data of CCl2(A(1)B(1) and a(3)B(1)) by NH3, H2O, CH2Br2, NH(CH3)(2), NH(C2H5)(2), N(C2H5)(3), and n-C6H14 were obtained by observing the time resolved fluorescence signals from the excited CCl2 radical transitions, which showed a superposition of two exponential decay components. The state-resolved rate constants k(A) and k(a) were acquired by analyzing and dealing with these data by using three-level-model, which was put forward by us.

关 键 词：动力学 猝灭速率常数 三能级模型 四氯化碳 CCL2自由基 卡宾 氩 脉冲放电 

分 类 号：O621.25[理学—有机化学]