H_(2)S^(+)在A^(2)A_(1)(v1=1,v2=8,v3=0)激发态的光解动力学  

Photodissociation Dynamics of H_(2)S^(+) via A^(2)A_(1)(1,8,0)Excited State

作　　者：李洁 王雅玲 谭玉欣 张宁 王文鑫 胡丽如 袁道福 王兴安[1] 杨学明[3,4] Jie Li;Yaling Wang;Yuxin Tan;Ning Zhang;Wenxin Wang;Liru Hu;Daofu Yuan;Xingan Wang;Xueming Yang(Department of Chemical Physics,University of Science and Technology of China,Hefei 230026,China;Hefei National Research Center for Physical Science at the Microscale,University of Science and Technology of China,Hefei 230026,China;State Key Laboratory of Molecular Reaction Dynamics,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China;Department of Chemistry,School of Science,Southern University of Science and Technology,Shenzhen 518055,China)

机构地区：[1]中国科学技术大学化学物理系,合肥230026 [2]中国科学技术大学合肥微尺度物质科学国家研究中心,合肥230026 [3]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 [4]南方科技大学理学院化学系,深圳518055

出　　处：《Chinese Journal of Chemical Physics》2024年第2期271-278,I0103,共9页化学物理学报（英文）

基　　金：This work was supported by the National Natural Science Foundation of China(No.22125302).

摘　　要：振动激发在分子和离子的光解动力学中有着重要的作用:开展特定振动激发态分子离子的光解离动力学实验研究存在很大挑战,尤其是实现合频振动激发离子的量子态选择的制备.本文利用时间切片离子速度成像技术研究了H_(2)S^(+)离子经A^(2)A_(1)(v1=1,v2=8,v3=0)激发态解离生成S^(+)(4S)和H_(2)的光解动力学.实验结合多光子电离和共振激发技术制备了振动激发的H_(2)S^(+),获得了离子在357.02~358.38nm范围内六个光解波长下产物S^(+)的速度影像.根据实验影像,获得了产物的总平动能谱和不同转动态的角分布各项异性参数特别指出地是在很窄的光解能量范围内,转动产物H_(2)(J=1)和H_(2)(J=3)的分支比出现多次反转,该现象与A^(2)A_(1)态单一振动模式激发的H2S+离子的光解动力学行为有明显不同.该研究表明,合频振动激发的H_(2)S^(+)离子光解动力学中可能存在振动模式之间的协同效应.Excitation of vibration plays an important role in the photodissociation dynamics of molecules and ions.Experiments on the photodissociation dynamics of molecular ions via well-defined excited vibrational states present a formidable challenge,particularly when it comes to the selective preparation of ions at the vibrational combination level.Here,using time-sliced velocity map ion imaging,the photodissociation of H_(2)S^(+)via A^(2)A_(1)(ν1=1,ν2=8,ν3=0,K=1)state leading to S^(+)(4S)and H_(2) products was investigated.The excited H_(2)S^(+)cations were prepared by multiphoton ionization of H_(2)S,followed by resonant excitation.Images of S+ions were captured at six wavelengths ranging from 357.02 nm to 358.38 nm.From the ion images,the total kinetic energy release distributions and rotational state-specific anisotropy parameters were derived.Notably,repeatedly reversed branching ratios of the H_(2)(J=1)and H_(2)(J=3)rotational states were observed in a narrow photolysis energy region.This behavior was totally different from the results in recent studies on the photodissociation of H_(2)S^(+)where only a single vibrational modeν2 was excited for parent ions in A^(2)A_(1)(ν1,ν2,ν3)states.The present study indicates that potential vibrational synergy effect was observed in the photodissociation dynamics of H_(2)S^(+)when the parent ions were excited in a combinational vibrational mode.

关 键 词：H_(2)S^(+)离子 离子速度成像 合频振动模式 光解动力学 

分 类 号：O643.1[理学—物理化学]