Vacuum Ultraviolet Photodissociation Dynamics of OCS via the F Rydberg State:theS(^(3)P_(J=2,1,0))Product Channels  

OCS分子在里德堡F态的真空紫外光解动力学:S(^(3)P_(J=2,1,0))产物通道

作　　者：Ling Tang Wentao Chen Daofu Yuan Shengrui Yu Xueming Yang Xingan Wang 唐翎;陈文韬;袁道福;俞盛锐;杨学明;王兴安(中国科学技术大学化学物理系,合肥230026;浙江师范大学杭州高等研究院,杭州311231;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;南方科技大学理学院,深圳518055)

机构地区：[1]Department of Chemical Physics,University of Science and Technology of China,Hefei 230026,China [2]Hangzhou Institute of Advanced Studies,Zhejiang Normal University,Hangzhou 311231,China [3]State key Laboratory of Molecular Reaction Dynamics,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China [4]School of Science,Southern University of Science and Technology,Shenzhen 518055,China

出　　处：《Chinese Journal of Chemical Physics》2022年第2期249-256,I0001,共9页化学物理学报（英文）

基　　金：supported by the National Key R&D Program of China(No.2016YFF0200500);the National Natural Science Foundation of China(No.22125302)。

摘　　要：Vacuum ultraviolet(VUV)photodissociation dynamics of carbonyl sulfide was investigated experimentally by using a tunable photolysis light source and the timesliced velocity map ion imaging technique.Ion images of S(^(3)P_(J=2,1,0))dissociation products were measured at five photolysis wavelengths from 133.26 nm to 139.96 nm,corresponding to the F Rydberg state of OCS.Two dissociation channels:S(^(3)P_(J))+CO(X^(1)Σ+)and S(^(3)P_(J))+CO(A^(3)Π)were observed with the former being dominant.The vibrational states of CO co-products were partially resolved in the ion images.The product total kinetic energy releases,anisotropy parameters(β),and the branching ratios of high-lying CO vibrational states were determined for the S(^(3)P_(J))+CO(X^(1)Σ^(+))channel.We found that the anisotropy parameters suddenly changed from negative to positive when OCS was excited to the higher vibrational levels of the F state.Furthermore,the anisotropy parameters for S(^(3)P_(J))products of J=2,1,0 were even different.These anomalous phenomena may result from the simultaneous existence of both parallel and perpendicular dissociation mechanisms,suggesting the involvement of other electronic states with different symmetry in the initially-excited energy region.This work provides a further understanding of the nonadiabatic couplings in the VUV photodissociation process of OCS.

关 键 词：Vacuum ultraviolet photodissociation Velocity map ion imaging Carbonyl sulfide 

分 类 号：O643.1[理学—物理化学]