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Photoabsorption and Photoionization of Acetaldehyde in the 10.8-21.4 eV Range.
Milton M Fujimoto1, Bruno Credidio2, Manoel G P Homem3
1Departamento de Física, Universidade Federal do Paraná, 81531-980 Curitiba, Paraná, Brazil.
ACS Omega
|December 1, 2025
Summary
This study presents new experimental and theoretical data on acetaldehyde photoabsorption and photoionization. These findings are crucial for understanding photochemical processes in atmospheric and astrophysical environments.
Area of Science:
- Physical Chemistry
- Atomic and Molecular Physics
- Photochemistry
Background:
- Acetaldehyde is a key molecule in atmospheric and astrophysical chemistry.
- Limited data exists on acetaldehyde's photoabsorption and photoionization in the vacuum-ultraviolet (VUV) range.
Purpose of the Study:
- To experimentally and theoretically investigate acetaldehyde's photoabsorption and photoionization cross sections in the VUV energy range.
- To provide a comprehensive dataset for photochemical modeling.
Main Methods:
- Experimental measurements using a double-ion-chamber spectrometer.
- Theoretical calculations employing Padé approximant and single-center partial-wave expansion methods.
- Solving the Lippmann-Schwinger equation for asymmetry parameters and photoionization cross sections.
Main Results:
- Measured absorption cross sections and ionization efficiency in the 10.8-21.4 eV and 13.5-21.4 eV ranges, respectively.
- Derived photoionization and neutral-decay cross sections.
- Calculated asymmetry parameters and photoionization cross sections for seven valence orbitals up to 35 eV.
Conclusions:
- Good agreement between experimental and theoretical results, and with existing literature.
- The comprehensive dataset is essential for modeling photochemical processes.
- Results aid in correlating ionic fragmentation pathways with dissociative photoionization.
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