Chang Yao, Fu Yanlin, Chen Zhichao, Luo Zijie, Zhao Yarui, Li Zhenxing, Zhang Weiqing, Wu Guorong, Fu Bina, Zhang Dong H, Ashfold Michael N R, Yang Xueming, Yuan Kaijun
State Key Laboratory of Molecular Reaction Dynamics, Dalian Coherent Light Source, Dalian Institute of Chemical Physics, Chinese Academy of Sciences 457 Zhongshan Road Dalian 116023 China
Marine Engineering College, Dalian Maritime University Liaoning 116026 China.
Chem Sci. 2023 Aug 1;14(31):8255-8261. doi: 10.1039/d3sc03328g. eCollection 2023 Aug 9.
The emergence of molecular oxygen (O) in the Earth's primitive atmosphere is an issue of major interest. Although the biological processes leading to its accumulation in the Earth's atmosphere are well understood, its abiotic source is still not fully established. Here, we report a new direct dissociation channel yielding S(D) + O(aΔ/XΣ) products from vacuum ultraviolet (VUV) photodissociation of SO in the wavelength range between 120 and 160 nm. Experimental results show O production to be an important channel from SO VUV photodissociation, with a branching ratio of 30 ± 5% at the H Lyman-α wavelength (121.6 nm). The relatively large amounts of SO emitted from volcanic eruptions in the Earth's late Archaean eon imply that VUV photodissociation of SO could have provided a crucial additional source term in the O budget in the Earth's primitive atmosphere. The results could also have implications for abiotic oxygen formation on other planets with atmospheres rich in volcanically outgassed SO.
地球原始大气中分子氧（O）的出现是一个备受关注的重要问题。尽管导致其在地球大气中积累的生物过程已为人熟知，但其非生物来源仍未完全明确。在此，我们报告了一个新的直接解离通道，该通道在120至160纳米波长范围内，通过真空紫外线（VUV）对SO的光解离产生S(D) + O(aΔ/XΣ)产物。实验结果表明，O的产生是SO VUV光解离的一个重要通道，在氢莱曼α波长（121.6纳米）处的分支比为30±5%。在地球太古宙晚期，火山喷发释放出相对大量的SO，这意味着SO的VUV光解离可能在地球原始大气的氧预算中提供了一个关键的额外来源项。这些结果也可能对其他拥有富含火山排放SO的大气的行星上的非生物氧形成产生影响。
