Multiphoton Ionization/Dissociation of Molecular Sulfur S2 in the UV Region
The multiphoton ionization/dissociation dynamics of molecular sulfur (S2) in the ultraviolet range of 205–300 nm is studied using velocity map ion imaging (VMI). In this one-color experiment, molecular sulfur (S2) is generated in a pulsed discharge and then photodissociated by UV radiation. At the t...
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Published in | The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Vol. 128; no. 20; pp. 4030 - 4037 |
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Main Authors | , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
American Chemical Society
23.05.2024
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Subjects | |
Online Access | Get full text |
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Summary: | The multiphoton ionization/dissociation dynamics of molecular sulfur (S2) in the ultraviolet range of 205–300 nm is studied using velocity map ion imaging (VMI). In this one-color experiment, molecular sulfur (S2) is generated in a pulsed discharge and then photodissociated by UV radiation. At the three-photon level, superexcited states are accessed via two different resonant states: the B 3Σu – (v′ = 8–11) valence states at the one-photon level and a Rydberg state at the two-photon level. Among the decay processes of these superexcited states, dissociation to electronically excited S atoms is dominant as compared to autoionization to ionic states S2 + (X 2Πg) at wavelengths λ < 288 nm. The anisotropy parameter extracted from these images reflects the parallel character of these electronic transitions. In contrast, autoionization is found to be particularly efficient at S(1D) and S(1S) detection wavelengths around 288 nm. Information obtained from the kinetic energy distributions of S atoms has revealed the existence of vibrationally excited S2 + (X 2Πg (v + > 11)) that dissociates to ionic products following one-photon absorption. This work also reveals many interesting features of S2 photodynamics compared to those of electronically analogous O2. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1089-5639 1520-5215 |
DOI: | 10.1021/acs.jpca.4c02134 |