TY  - EJOUR
AU  - Mayer, D.
AU  - Lever, F.
AU  - Picconi, David
AU  - Metje, J.
AU  - Alisauskas, S.
AU  - Calegari, F.
AU  - Düsterer, S.
AU  - Ehlert, C.
AU  - Feifel, R.
AU  - Niebuhr, M.
AU  - Manschwetus, B.
AU  - Kuhlmann, M.
AU  - Mazza, T.
AU  - Robinson, M. S.
AU  - Squibb, R. J.
AU  - Trabattoni, A.
AU  - Wallner, M.
AU  - Saalfrank, P.
AU  - Wolf, T. J. A.
AU  - Gühr, M.
TI  - Following excited-state chemical shifts in molecular ultrafast x-ray photoelectron spectroscopy
IS  - arXiv:2102.13431
M1  - PUBDB-2024-07841
M1  - arXiv:2102.13431
PY  - 2021
AB  - The conversion of photon energy into other energetic forms in molecules is accompanied by charge moving on ultrafast timescales. We directly observe the charge motion at a specific site in an electronically excited molecule using time-resolved x-ray photoelectron spectroscopy (TR-XPS). We extend the concept of static chemical shift from conventional XPS by the excited-state chemical shift (ESCS), which is connected to the charge in the framework of a potential model. This allows us to invert TR-XPS spectra to the dynamic charge at a specific atom. We demonstrate the power of TR-XPS by using sulphur 2p-core-electron-emission probing to study the UV-excited dynamics of 2-thiouracil. The new method allows us to discover that a major part of the population relaxes to the molecular ground state within 220-250 fs. In addition, a 250-fs oscillation, visible in the kinetic energy of the TR-XPS, reveals a coherent exchange of population among electronic states.
LB  - PUB:(DE-HGF)25
C6  - pmid:35017539
UR  - https://bib-pubdb1.desy.de/record/619702
ER  -