Journal Article

PUBDB-2025-04805

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Dissociative Photoionization of 2-Thiouracil and 4-Thiouracil: A Molecular Dynamics Study

Roy, B. ; Titov, E. (Corresponding author)Extern* ; Robinson, M. S.CFEL*Extern*XFEL.EU* ; Guehr, M.Extern*XFEL.EU*DESY* ; Saalfrank, P.Extern*XFEL.EU*

2025
American Chemical Society Washington, DC

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Please use a persistent id in citations: doi:10.1021/acs.jpca.5c03342  doi:10.3204/PUBDB-2025-04805

Abstract: Thionated nucleobases have drawn considerable attention due to their role in medical treatment and biology, which triggered studies of their photophysics and photochemistry using various experimental and theoretical techniques. In particular, vacuum ultraviolet (VUV)-induced dissociative photoionization of 2-thiouracil (2-TU) has been recently studied using synchrotron radiation [Robinson et al., Molecules 2023, 28, 2354]. Here, using molecular dynamics simulations at the semiempirical OM2 level, we study the fragmentation dynamics of the cations of 2-TU and its isomer, 4-thiouracil (4-TU). Considering various VUV photon energies, we calculate energy-resolved mass spectra and breakdown diagrams for 2-TU and 4-TU. Remarkably, we find that the major fragments are different between the two compounds: 69 amu (C3NH3O+) for 2-TU and 85 amu (C3NH3S+) for 4-TU. Our simulations provide direct mechanistic insight into this observation and the fragmentation processes of thionated uracils in general.

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Contributing Institute(s):

1. FS-FLASH (FS-FLASH)

Research Program(s):

1. 631 - Matter – Dynamics, Mechanisms and Control (POF4-631) (POF4-631)
2. SFB 1636 A03 - Bindungsaktivierung und molekulare Dynamik an Metallnanopartikeln untersucht mittels Röntgenspektroskopie (A03) (535988987) (535988987)
3. SFB 1636 B05 - Mechanismen photochemischer Reaktionen an metallischen Nanopartikeln (B05) (536025008) (536025008)

Experiment(s):

1. No specific instrument

Appears in the scientific report 2025

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Database coverage:
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