Direct Observation of the <i>ππ*</i> to <i>nπ*</i> Transition in 2-Thiouracil via Time-Resolved NEXAFS Spectroscopy.

ABSTRACT: The photophysics of nucleobases has been the subject of both theoretical and experimental studies over the past decades due to the challenges posed by resolving the steps of their radiationless relaxation dynamics, which cannot be described in the framework of the Born-Oppenheimer approximation (BOA). In this context, the ultrafast dynamics of 2-thiouracil has been investigated with a time-resolved NEXAFS study at the Free Electron Laser FLASH. Near Edge X-ray Absorption Fine Structure spectroscopy (NEXAFS) can be used to observe electronic transitions in ultrafast molecular relaxation. We performed time-resolved UV-pump/X-ray probe absorption measurements at the sulfur 2s (L1) and 2p (L2/3) edges. We are able to identify absorption features corresponding to the S2 (ππ*

SUBMITTER: Lever F 

PROVIDER: S-EPMC12035857 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature