A study of the valence shell photoionization dynamics following core level resonant excitation in imidazole
Year: 2026
Type: preprint
Abstract: The photoionization and subsequent Auger decay dynamics of core-excited states in imidazole have been investigated at the carbon and nitrogen K-edges using linearly polarized synchrotron radiation. Ion yield measurements in the pre-edge regions were used to locate core-level transitions into either unoccupied valence or Rydberg states, and assignments were made through comparison with simulated spectra obtained using the RASPT2 method. Valence shell photoelectron spectra were recorded at photon energies coinciding with these core-level transitions, using two polarization orientations to allow the photoelectron angular distributions to be determined. The interpretation of these resonantly excited photoelectron spectra was guided by RASPT2 simulations that helped distinguish between participator and spectator contributions. Autoionization strongly affects the photoelectron intensity and angular distributions of the outer valence 1h states. Spectator contributions become evident at binding energies above 15 eV, and some of the intense 2h-1p states are well-described by the calculations, allowing assignments to be proposed. The non-resonantly excited C(KVV) and N(KVV) Auger spectra have been measured and some of the features at high kinetic energies have been assigned.
Source: ChemRxiv
Language: English
Subfield: Radiation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7221508706