Vacuum ultraviolet(VUV)pho-todissociation dynamics of carbonyl sulfide was investigated experimen-tally by using a tunable photol-ysis light source and the time-sliced velocity map ion imaging tech-nique.Ion images of S(3PJ=2,1,0)dissociation products were mea-sured at five photolysis wavelengths from 133.26 nm to 139.96 nm,corresponding to the F Rydberg state of OCS.Two dissociation channels:S(3PJ)+CO(X1∑+)and S(3PJ)+CO(A3Π)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(3PJ)+CO(X1Σ+)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 pa-rameters for S(3PJ)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.

Ling Tang;Wentao Chen;Daofu Yuan;Shengrui Yu;Xueming Yang;Xingan Wang

Department of Chemical Physics,University of Science and Technology of China,Hefei 230026,China;Hangzhou Institute of Advanced Studies,Zhejiang Normal University,Hangzhou 311231,China;State key Laboratory of Molecular Reaction Dynamics,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,China;School of Science,Southern University of Science and Technology,Shenzhen 518055,China

化学物理学报（英文版）

[1]Ling Tang;Wentao Chen;Daofu Yuan;Shengrui Yu;Xueming Yang;Xingan Wang-.Vacuum Ultraviolet Photodissociation Dynamics of OCS via the F Rydberg State:the S(3PJ=2,1,0)Product Channels)[J].化学物理学报（英文版）,2022(02):249-256

Photodissociation,3PJ,todissociation,photol,+CO,photodissociation

Vacuum,Ultraviolet,Dynamics,OCS,via,Rydberg,State,Product,Channels,ultraviolet,VUV,dynamics,carbonyl,sulfide,was,investigated,experimen,tally,by,using,tunable,light,source,sliced,velocity,map,imaging,tech,nique,Ion,images,products,were,mea,sured,five,photolysis,wavelengths,from,corresponding,Two,channels,X1,A3,observed,former,being,dominant,vibrational,states,partially,resolved,total,kinetic,energy,releases,anisotropy,parameters,branching,ratios,lying,determined,We,found,that,suddenly,changed,negative,positive,when,excited,higher,levels,Furthermore,even,different,These,anomalous,phenomena,may,result,simultaneous,existence,both,parallel,perpendicular,mechanisms,suggesting,involvement,other,electronic,symmetry,initially,region,This,work,provides,further,understanding,nonadiabatic,couplings,process

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