Freiburg 2024 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

MO: Fachverband Molekülphysik

MO 16: Ultrafast Dynamics I

MO 16.4: Talk

Wednesday, March 13, 2024, 15:15–15:30, HS 3044

Investigating the ultrafast dynamics of photoexcited azobenzene with an x-ray free electron laser — •Fabiano Lever¹, Dennis Mayer¹, Atia Tul Noor¹, Gesa Goetzke¹, Julius Schwarz², Michael Martins², Rebecca Ingle³, Stefan Duesterer¹, Steffen Palutke¹, Taran Dexter Cyrus Driver⁴, Ulrike Fruehling¹, and Markus Gühr¹ — ¹DESY, Hamburg, DE — ²Hamburg Universität, DE — ³UCL, London, UK — ⁴SLAC, Menlo Park, USA

Ultraviolet excitation triggers a light-induced isomerization reaction in the molecular switch azobenzene, changing its geometry from the trans ground state into the cis isomer. This work presents results from an ultrafast UV pump / soft x-ray probe experiment at the Free-Electron Laser FLASH. The electronic state dynamics of photoexcited azobenzene is probed with time-resolved x-ray absorption and photoelectron spectroscopy. In both observables, we measure dynamical features on a sub-picosecond scale. Comparing the experimental results to theoretical calculations for both datasets, we identify the ultrafast relaxation of the initially photoexcited S2 (ππ*) to lower states.