Photodissociation of CO2 via the 1Πg state: Wavelength-dependent imaging studies of O(1D2) photoproducts

Liu，Qian1; Gao，Qinghua1; Liu，Peng1; Yang，Xueming1,2,3; Yu，Shengrui1

2024-01-07

10.1063/5.0180860

Journal of Chemical Physics   影响因子和分区

0021-9606

1089-7690

Photodissociation of CO via the Π state is investigated using a time-sliced velocity-mapped ion imaging apparatus combined with a tunable vacuum ultraviolet photolysis source. The main O(D) + CO(Xς) channel is directly observed from the measured images of O(D) photoproducts at 129.08-134.76 nm. The total kinetic energy release spectra determined based on these images show that the energetic thresholds for the O(D) + CO(Xς) photoproducts correspond to the thermochemical thresholds for the photodissociation of CO(v = 0) and CO(v = 1). One significant difference among the CO(Xς, v) vibrational distributions for the predominant CO(v = 0) dissociation is that the population of CO(v = 0) becomes favorable at 130.23-133.45 nm compared to the Boltzmann-like component (v > 0) that always exists at 129.08-134.76 nm. The wavelength dependences of the overall β are found to follow the variation trend of the CO(v = 0) abnormal intensity. The vibrational state-specific β values present a roughly decreasing trend with an increase in v, whereas β(v = 0) appears to be significantly larger than β(v = 1) at 130.23-133.45 nm compared to 134.76 and 129.08 nm. The non-statistical CO(v = 0) with larger β values at 130.23-133.45 nm implies that an additional pathway may open through the conical intersection coupling to the dissociative 2A′ state, except for the ever-existing pathway that yields the Boltzmann-like component. In contrast, at 129.08 nm, the restoration of the statistical equilibrium in the CO(Xς, v) vibrational distribution may be caused by the emergence of novel dissociation pathways arising from the participation of the 3A″ state.

SCI ; EI

英语

其他

CHEMISTRY

2-s2.0-85181414951

Scopus

1.Hangzhou Institute of Advanced Studies,Zhejiang Normal University,Hangzhou,1108 Gengwen Road Zhejiang Province,311231,China
2.State Key Laboratory of Molecular Reaction Dynamics,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian,457 Zhongshan Road, Liaoning Province,116023,China
3.Department of Chemistry,College of Science,Southern University of Science and Technology,Shenzhen,1088 Xueyuan Road,518055,China

Liu，Qian,Gao，Qinghua,Liu，Peng,et al. Photodissociation of CO2 via the 1Πg state: Wavelength-dependent imaging studies of O(1D2) photoproducts[J]. Journal of Chemical Physics,2024,160(1).

Liu，Qian,Gao，Qinghua,Liu，Peng,Yang，Xueming,&Yu，Shengrui.(2024).Photodissociation of CO2 via the 1Πg state: Wavelength-dependent imaging studies of O(1D2) photoproducts.Journal of Chemical Physics,160(1).

Liu，Qian,et al."Photodissociation of CO2 via the 1Πg state: Wavelength-dependent imaging studies of O(1D2) photoproducts".Journal of Chemical Physics 160.1(2024).