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.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10411858PMC
http://dx.doi.org/10.1039/d3sc03328gDOI Listing

Publication Analysis

Top Keywords

vuv photodissociation
12
vacuum ultraviolet
8
earth's atmosphere
8
earth's primitive
8
primitive atmosphere
8
earth's
5
photodissociation
4
ultraviolet photodissociation
4
photodissociation sulfur
4
sulfur dioxide
4

Similar Publications

A chlorine-substituted Criegee intermediate, ClCHOO, is photolytically generated using a diiodo precursor, detected by VUV photoionization at 118 nm, and spectroscopically characterized via ultraviolet-visible (UV-vis)-induced depletion of / = 80 under jet cooled conditions. UV-vis excitation resonant with a π* ← π transition yields a significant ground state depletion, indicating a strong electronic transition and rapid photodissociation. The broad absorption spectrum peaks at 350 nm and is attributed to contributions from both (∼70%) and (∼30%) conformers of ClCHOO based on spectral simulations using a nuclear ensemble method.

View Article and Find Full Text PDF

The dicarbon molecule, C, is one of the most important diatomic species in various gaseous environments. Despite extensive spectroscopic studies in the last two centuries, the radiative and photodissociative properties of C in its highly excited electronic states are still largely unexplored, particularly in the short vacuum ultraviolet (VUV) region. In this study, the lifetimes of C for rotational levels in the recently identified 1Σ state up to the vibrational level ν' = 4 and in the Σ state up to ν' = 2 are measured for the first time with a VUV-pump-UV-probe photoionization scheme.

View Article and Find Full Text PDF

The radiative and photodissociative properties of the dicarbon molecule, C, in high-lying electronic states are of utmost importance for modeling the photochemical processes that occur in various astronomical environments. Despite extensive spectroscopic studies in the last two centuries, the photodissociation properties of C are still largely unknown, particularly for quantum states in the vacuum ultraviolet (VUV) region. Here, the lifetimes of C for each individual rovibrational level in the recently identified 2Σ state are measured for the first time using a VUV-pump-UV-probe photoionization scheme.

View Article and Find Full Text PDF

Growth mechanism of aromatic prebiotic molecules: insights from different processes of ion-molecule reactions in benzonitrile-ammonia and benzonitrile-methylamine clusters.

Phys Chem Chem Phys

August 2024

MOE Key Laboratory of Laser Life Science & Guangdong Provincial Key Laboratory of Laser Life Science, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, College of Biophotonics, South China Normal University, Guangzhou 510631, China.

Benzonitrile (BN, CHCN) has been detected in the cold molecular cloud Taurus molecular cloud-1 (TMC-1) in 2018, which is suggested to be a precursor in the formation of more complex nitrogen-containing aromatic interstellar compounds. In this study, we utilized mass-selected infrared (IR) photodissociation spectroscopy and quantum chemical calculations to investigate the structures and gaseous ion-molecule reactions of benzonitrile-ammonia (BN-NH) and benzonitrile-methylamine (BN-MA) clusters. The spectral observations indicate that the cyclic hydrogen bonding structure predominates in both neutral clusters.

View Article and Find Full Text PDF

Under irradiation of a vacuum ultraviolet (VUV) photon, methane dissociates and yields multiple fragments. This photochemical behavior is not only of fundamental importance but also with wide-ranging implications in several branches of science. Despite that and numerous previous investigations, the product channel branching is still under debate, and the underlying dissociation mechanisms remain elusive.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!