Photodissociation Dynamics of 2-1odotoluene Investigated by Femtosecond Time-Resolved Mass Spectrometry  

邻碘甲苯分子光解动力学的飞秒时间分辨质谱研究

作　　者：刘志明[1] 王艳梅[1] 胡春龙[1] 龙金友[1] 张冰[1] 

机构地区：[1]中国科学院武汉物理与数学研究所,波谱与原子分子物理国家重点实验室,武汉430071

出　　处：《Chinese Journal of Chemical Physics》2016年第1期53-58,I0001,共7页化学物理学报（英文）

基　　金：This work was supported by the National Basic Research Program of China （973 Program） （No.2013CB922200） and the National Natural Science Foundation of China （No.91121006, No.21273274, No.21173256, and No.21303255）.

摘　　要：The photodissociation dynamics of 2-iodotoluene following excitation at 266 nm have been investigated employing femtosecond time-resolved mass spectrometry. The photofragments are detected by multiphoton ionization using an intense laser field centered at 800 nm. A dissociation time of 3804-50 fs was measured from the rising time of the co-fragments of toluene radical （C7H7） and iodine atom （I）, which is attributed to the averaged time needed for the C-I bond breaking for the simultaneously excited nσ and ππ＊ states by 266 nm pump light. In addition, a probe light centered at 298.23 nm corresponding to resonance wavelength of ground-state iodine atom is used to selectively ionize ground-state iodine atoms generated from the dissociation of initially populated hσ＊ and ππ＊ states. And a rise time of 4004-50 fs is extracted from the fitting of time-dependent I＋ transient, which is in agreement with the dissociation time obtained by multiphoton ionization with 800 nm, suggesting that the main dissociative products are ground-state iodine atoms.

关 键 词：resolved mass 2-1odotoluene PHOTODISSOCIATION Dissociation time Femtosecond timespectrometry 

分 类 号：O[理学]