Ultrafast Photodissociation Dynamics of the F State of Sulfur Dioxide by Femtosecond Time-Resolved Pump-Probe Method
Ultrafast Photodissociation Dynamics of the F State of Sulfur Dioxide by Femtosecond Time-Resolved Pump-Probe Method
复制标题
DOI：
10.1088/0256-307x/28/3/033301
复制
发表时间：
2011-03
影响因子：
3.5
通讯作者：
Dongdong Zhang;Qiang Ni;Sizuo Luo;Jing Zhang;Hang Liu;Haifeng Xu;M. Jin;D. Ding
中科院分区：
文献类型：
--
作者：
Dongdong Zhang;Qiang Ni;Sizuo Luo;Jing Zhang;Hang Liu;Haifeng Xu;M. Jin;D. Ding
利用飞秒泵浦-探测法研究了二氧化硫的解离动力学。通过吸收267 nm飞秒激光脉冲的两个光子，并在两个激光之间的不同延迟时间被400 nm激光脉冲电离，SO2分子被激发到F态。观察到了母离子(SO+2)和碎片离子(SO+、S+和O+)的瞬变现象。SO+2的瞬变可以很好地符合双指数衰减，其快分量和慢分量的寿命分别为280ps和2.97ps。SO+瞬变由270ps和2.50ps两个生长分量组成。结果表明，SO2的F态沿S-O键解离。然而，S+和O+的瞬变具有不同的行为，由快速增长和长衰减组成。讨论了碎片形成的可能机制，以了解SO2 F态的解离动力学。
A femtosecond pump-probe method is employed to study the dissociation dynamics of sulfur dioxide. SO2 molecules are excited to the F state by absorbing two photons of 267 nm femtosecond laser pulses, and ionized by 400 nm laser pulses at different delay times between the two lasers. Transients of both parent ions (SO+2) and the fragment ions (SO+, S+ and O+) are observed. The SO+2 transient can be well fitted to a biexponential decay comprising a fast and a slow component of 280 fs and 2.97 ps lifetimes, respectively. The SO+ transient consists of two growth components of 270 fs and 2.50 ps. The results clearly show that the F state of SO2 dissociates along an S-O bond. The transients of S+ and O+, however, have different behavior, which consist of a fast growth and a long decay component. A possible mechanism of the fragment formation is discussed to understand the dissociation dynamics of the F state of SO2.