飞秒泵浦-探测质谱方法研究苯内转换动力学(英文)  

Internal Conversion Dynamics of Benzene Studied by Femtosecond Pump-probe Mass Spectroscopy

作　　者：尹淑慧[1] 刘红平[1] 张建阳[1] 姜波[1] 王利[1] 沙国河[1] 楼南泉[1] 

机构地区：[1]中国科学院大连化学物理研究所分子反应动力学国家重点实验室,大连116023

出　　处：《Chinese Journal of Chemical Physics》2003年第3期171-175,共5页化学物理学报（英文）

基　　金：国家自然科学基金资助项目 ( 2 983 3 0 80 ,2 995 3 0 0 1)

摘　　要：以飞秒 40 0及 2 66nm激光脉冲结合泵浦 探测飞行时间质谱方法研究了苯S2 态内转换动力学 .40 0nm双光子过程将苯分子激发到S2 电子态 ,布居在S2 电子态的分子由于能级耦合无辐射弛豫到S1电子态 .通过测定C6 H6 +讯号强度随泵浦 探测延迟时间的改变 ,获得苯S2 及S1电子态的衰减寿命分别为 ( 48± 1)fs及 ( 6.5± 0 .2 )ps ,S2The detection of benzene photolons in pump-probe experiments with the fermosecond laser pulse at 400 and 266 nm has allowed to study the dynamics of the internal conversion after excitation to the electronic S-2 state. For the S-2 state, an extremely short lifetime tau(D1) = ( 48 +/- 1) fs has been obtained, whereas the lifetime tau(D2) = ( 6.5 +/- 0.2) ps of the S-1 state populated by the internal conversion from the S-2 state is longer than that of the S-2 state. The deactivation of the S-2 state as well as the S-1 state has been explained by the internal conversion to lower electronic states caused by the conical intersection of the corresponding potential surfaces.

关 键 词：寿命 泵浦-探测 内转换 

分 类 号：O657.3[理学—分析化学] O657.63[理学—化学]