Here we report the study of the photodissociation dynamics of carbonyl sulfide in the vacuum ultraviolet region using the time-sliced velocity map ion imaging technique.Images of S(^3PJ=2,1,0),S(^1D2)and S(^1S0)produc...Here we report the study of the photodissociation dynamics of carbonyl sulfide in the vacuum ultraviolet region using the time-sliced velocity map ion imaging technique.Images of S(^3PJ=2,1,0),S(^1D2)and S(^1S0)products were measured at four photolysis wave-lengths of 129.32,128.14,126.99,and 126.08 nm,respectively.Four main dissociation channels:S(^3PJ=2,1,0)+CO(X^1Σ^+),S(^3PJ=2,1,0)+CO(A^3π),S(^1D2)+CO(X^1Σ^+)and S(^1S0)+CO(X^1Σ^+)channels,have been clearly observed and identified.Vibrational states of the CO co-products were partially resolved in the experimental images.From these images,the product total kinetic energy releases,the branching ratios and angular distributions of products have been derived.While the S(^3PJ=2,1,0)+CO(A^3π)product channel is formed through the adiabatic dissociation process after the excitation to the(3^1Σ^+)excited state,the results suggest that strong nonadiabatic coupling plays an important role in the formation of other three channels.展开更多
Ion-pair dissociation is an important molecular process and frequently happens when the target molecule is pumped to its electronically superexcited states. In contrast to the experimental studies of photoexcitation i...Ion-pair dissociation is an important molecular process and frequently happens when the target molecule is pumped to its electronically superexcited states. In contrast to the experimental studies of photoexcitation ion-pair dissociation, there are some experimental challenges in the electron-impact ion-pair dissociation study, in particular, on determination of the energetic threshold. Here we report an experimental development for the ion-pair dissociation study by using the monochromized electron impacts. As an example, the threshold of BrCN→Br^-+CN^+ is determined as 13.78 eV according to the appearance energy of CN^+ signals, meanwhile, the time-sliced ion velocity image of CN^+ is recorded at 16.09 eV and indicates an anisotropic distribution of the CN^+ momentum.展开更多
We study the phot odissociation dynamics of CS2 in the ultraviolet region using the time-sliced velocity map ion imaging technique.The S(3 Pj)+CS(X1E+)product channels were observed and identified at four wavelengths ...We study the phot odissociation dynamics of CS2 in the ultraviolet region using the time-sliced velocity map ion imaging technique.The S(3 Pj)+CS(X1E+)product channels were observed and identified at four wavelengths of 201.36,203.10,204.85 and 206.61 nm.In the measured images of S(3Pj=2,1,0),the vibrational states of the CS(X1E+)co-products were partially resolved and the vibrational state distributions were determined.Moreover,the product total kinetic energy releases and the anisotropic parameters were derived.The relatively small anisotropic parameter values indicate that the S(3Pj=2丄0)+CS(X1E+)channels are very likely formed via the indirect predissociation process of CS2.The study of the S(3Pj=2,1;0)+CS(X1E+)channels,which come from the spin-orbit coupling dissociation process of CS2,shows that nonadiabatic process plays a role in the ultraviolet photodissociation of CS2.展开更多
基金supported by the National Natural Science Foundation of China(No.22125302,No.22173099,No.22288201,No.21873089,and No.21973037)the Guangdong Science and Technology Program(No.2019ZT08L455 and No.2019JC01X091)the Shenzhen Science and Technology Program(No.ZDSYS20200421111001787).
基金supported by the National Natural Science Foundation of China(20673140,20703060)Science and Technology Research Foundation of Hubei Provincial Department of Education,China(Z20082601)~~
基金supported by the National Key R&D Program of China (No.2016YFF0200500)the National Natural Science Foundation of China (No.21473173,No.21590802,No.21327901 and No.21773213)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences (No.XDB17000000)the Fundamental Research Funds for the Central Universities.
文摘Here we report the study of the photodissociation dynamics of carbonyl sulfide in the vacuum ultraviolet region using the time-sliced velocity map ion imaging technique.Images of S(^3PJ=2,1,0),S(^1D2)and S(^1S0)products were measured at four photolysis wave-lengths of 129.32,128.14,126.99,and 126.08 nm,respectively.Four main dissociation channels:S(^3PJ=2,1,0)+CO(X^1Σ^+),S(^3PJ=2,1,0)+CO(A^3π),S(^1D2)+CO(X^1Σ^+)and S(^1S0)+CO(X^1Σ^+)channels,have been clearly observed and identified.Vibrational states of the CO co-products were partially resolved in the experimental images.From these images,the product total kinetic energy releases,the branching ratios and angular distributions of products have been derived.While the S(^3PJ=2,1,0)+CO(A^3π)product channel is formed through the adiabatic dissociation process after the excitation to the(3^1Σ^+)excited state,the results suggest that strong nonadiabatic coupling plays an important role in the formation of other three channels.
基金supported by the National Natural Science Foundation of China (No.21625301)
文摘Ion-pair dissociation is an important molecular process and frequently happens when the target molecule is pumped to its electronically superexcited states. In contrast to the experimental studies of photoexcitation ion-pair dissociation, there are some experimental challenges in the electron-impact ion-pair dissociation study, in particular, on determination of the energetic threshold. Here we report an experimental development for the ion-pair dissociation study by using the monochromized electron impacts. As an example, the threshold of BrCN→Br^-+CN^+ is determined as 13.78 eV according to the appearance energy of CN^+ signals, meanwhile, the time-sliced ion velocity image of CN^+ is recorded at 16.09 eV and indicates an anisotropic distribution of the CN^+ momentum.
基金This work was supported by the National Key R&D Program of China(No.2017YFF0104500)the National Natural Science Foundation of China(No.21590802 and No.21473173)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB17000000).
文摘We study the phot odissociation dynamics of CS2 in the ultraviolet region using the time-sliced velocity map ion imaging technique.The S(3 Pj)+CS(X1E+)product channels were observed and identified at four wavelengths of 201.36,203.10,204.85 and 206.61 nm.In the measured images of S(3Pj=2,1,0),the vibrational states of the CS(X1E+)co-products were partially resolved and the vibrational state distributions were determined.Moreover,the product total kinetic energy releases and the anisotropic parameters were derived.The relatively small anisotropic parameter values indicate that the S(3Pj=2丄0)+CS(X1E+)channels are very likely formed via the indirect predissociation process of CS2.The study of the S(3Pj=2,1;0)+CS(X1E+)channels,which come from the spin-orbit coupling dissociation process of CS2,shows that nonadiabatic process plays a role in the ultraviolet photodissociation of CS2.