Recently,the team led by Researcher Yuan Kaijun from the Molecular Photochemical Kinetics Research Group (Group 2507) of Dalian Light Source Research Laboratory,in collaboration with Professor Mike Ashfold from the University of Bristol in the UK and Professor Hu Xixi from Nanjing University,revealed the photochemical kinetics of the high-electron excited state of interstellar hydrogen sulfide molecules and constructed the full-band and full-channel dissociation kinetics images of hydrogen sulfide.
Hydrogen sulfide molecules are one of the most important molecules in the solar nebula,and their photochemical processes are of great significance to the origin and evolution of interstellar media such as elemental sulfur,sulfhydryl radicals (SH),and hydrogen gas (H2). Although the research on the photodissociation of hydrogen sulfide molecules has received increasing attention,up to now,high-resolution and complete kinetic images have not been constructed at home and abroad.
In this work, Yuan Kaijun's team utilized the Dalian Coherent Light Source in combination with Rydberg hydrogen atom time-of-flight spectroscopy and time-slice ion imaging technology to measure the photochemistry of all product channels of hydrogensulfide in the extreme ultraviolet band. The experimental results show that the kinetics and quantum yield of the photolysis productsof hydrogensulfide have obvious wavelength-dependent characteristics. Theoretical calculations have clarified the complex non-adiabatic dissociation characteristics during the photolysis of hydrogen sulfide by constructing a high electron excitation potential energy surface. This work not only provides a scientific basis for the construction of the interstellar sulfur chemical model, but also offers a research example for the development of quantum dynamics theory.
In recent years, Yuan Kaijun's team has studied the extreme ultraviolet photochemistryof interstellar hydrogen sulfide molecules based on the Dalian Coherent Light Source System and measured the quantum yield of SH radicals generated by hydrogen sulfide photochemistry (Nature Communications, 2020). The rotational excitation-dependent photochemical reaction mechanism of hydrogen sulfide wasrevealed (Nature Communications, 2021), and it was proposed that the photochemical process of hydrogen sulfide is an important source of high-vibration-excited H2 in interstellar space (The Journal of Physical Chemistry Letters). (2022)
The related achievement is "The vibronic state dependent predissociation of H2S: The title "determination of all Fragmented processes" was published in Chemical Science and was selected as the cover article. The first author of this work is Zhao Yarui, a jointly trained doctoral student in Group 2507 of Dalian Institute of Chemical Physics. This work was supported by the National Natural Science Foundation of China, the Key Technology Team of the Chinese Academy of Sciences, the Xingliao Talent Program of Liaoning Province, and other projects. (Written and photographed by Zhao Yarui and Yuan Kaijun)
The article links: https://doi.org/10.1039/D2SC06988A
