Mapping Excited-State Decay Mechanisms in Acetylacetone by Sub-20 fs Time-Resolved Photoelectron Spectroscopy.

ABSTRACT: Excited-State Intramolecular Hydrogen Transfer (ESIHT) is one of the fastest chemical reactions, occurring on the order of tens of femtoseconds and playing a critical role in light-driven biological processes and technological applications. Here, we investigate the early stages of coupled nuclear-electron dynamics using acetylacetone (AcAc) as a model system exhibiting ESIHT. We employ ultraviolet-extreme ultraviolet (UV-XUV) time-resolved photoelectron spectroscopy (tr-PES) with sub-20 fs resolution in combination with high-level dynamically correlated simulations (CASPT2) to map the electronic relaxation pathways and vibrational modes driving this process. Our results provide distinct spectroscopic signatures of ESIHT occurring within the first 20 fs and resolve the active vibrational mo

SUBMITTER: Severino S 

PROVIDER: S-EPMC12395474 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature