Threshold photoelectron spectroscopy of small organo-selenium radicals
We present threshold photoelectron spectra of several reactive selenium-containing intermediates generated by pyrolysis of dimethyldiselenide, (CH<sub>3</sub>)<sub>2</sub>Se<sub>2</sub>. The detected species include CH<sub>3</sub>Se<sub>2</sub>, Se<sub>2</sub> and CH<sub>3</sub>Se radicals. Short-lived intermediates were produced <i>in situ</i> using a heated microreactor and characterized <i>via</i> mass-selected threshold photoelectron spectroscopy, using synchrotron radiation at the Swiss Light Source and a photoelectron-photoion coincidence (PEPICO) detection scheme. The data yield ionization energies for the transition into the ionic ground state of 8.28 eV ((CH<sub>3</sub>)Se<sub>2</sub>), 8.85 eV (Se<sub>2</sub>) and 8.92 eV ((CH<sub>3</sub>)Se). The values are accurate within ±10 to ±20 meV. In addition, transitions into excited electronic states of the ion were also investigated. Simulations of the vibrational structure based on quantum chemical calculations provide further insight into structural changes upon ionization. By directly comparing these results to previously studied sulfur and oxygen analogues, we identify both similarities and key differences in the bonding and fragmentation behavior of group 16 radicals.
Authors
- Emil Karaev (ORCID: https://orcid.org/0000-0002-0086-8585)
- Marius Gerlach (ORCID: https://orcid.org/0000-0002-7930-8061)
- Ingo Fischer (ORCID: https://orcid.org/0000-0001-8978-4013)
- Dorothee Schaffner (ORCID: https://orcid.org/0009-0003-6572-9214)
- Patrick Hemberger (ORCID: https://orcid.org/0000-0002-1251-4549)
- Sira Graetz
Institutions
- University of Würzburg (DE)
- Paul Scherrer Institute (CH)
Publication Details
- Journal
- Physical Chemistry Chemical Physics
- Published
- 2025-11-14
- DOI
- https://doi.org/10.1039/d5cp03519h
- Primary Topic
- Organoselenium and organotellurium chemistry
- Type
- article
- Field-Weighted Citation Impact
- 0.00