Stiel, HolgerBraenzel, JuliaJonas, AdrianGnewkow, RichardGlöggler, Lisa TheresaSommer, DennyKrist, ThomasErko, AlexeiTümmler, JohannesMantouvalou, Ioanna2022-10-102022-10-102021-12-151661-6596https://depositonce.tu-berlin.de/handle/11303/17563https://doi.org/10.14279/depositonce-16344The extension of the pump-probe approach known from UV/VIS spectroscopy to very short wavelengths together with advanced simulation techniques allows a detailed analysis of excited-state dynamics in organic molecules or biomolecular structures on a nanosecond to femtosecond time level. Optical pump soft X-ray probe spectroscopy is a relatively new approach to detect and characterize optically dark states in organic molecules, exciton dynamics or transient ligand-to-metal charge transfer states. In this paper, we describe two experimental setups for transient soft X-ray absorption spectroscopy based on an LPP emitting picosecond and sub-nanosecond soft X-ray pulses in the photon energy range between 50 and 1500 eV. We apply these setups for near-edge X-ray absorption fine structure (NEXAFS) investigations of thin films of a metal-free porphyrin, an aggregate forming carbocyanine and a nickel oxide molecule. NEXAFS investigations have been carried out at the carbon, nitrogen and oxygen K-edge as well as on the Ni L-edge. From time-resolved NEXAFS carbon, K-edge measurements of the metal-free porphyrin first insights into a long-lived trap state are gained. Our findings are discussed and compared with density functional theory calculations.en540 Chemie und zugeordnete WissenschaftenNEXAFSpump-probeporphyrinultrafast X-ray absorptionpseudoisocyanineTD-DFTArticle2022-09-031422-0067