Photoionization and electronic structure of chemical warfare agents

• Published in: Journal of electron spectroscopy and related phenomena Vol. 279; p. 147523
• Main Author: Novak, Igor
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2025
• Subjects: Chemical warfare agents; Electronic structure; Ionization energies; Photoelectron spectra; Toxicology; Chemical warfare agents; Photoelectron spectra; Ionization energies; Toxicology; Electronic structure
• ISSN: 0368-2048
• DOI: 10.1016/j.elspec.2025.147523

The vertical, valence ionization energies for several chemical warfare agents (CWA): nerve agents, choking agents and blister agents have been calculated (as free molecules) using high-level ab initio coupled-cluster method: IP-EOM-CCSD. The calculated vertical, valence ionization energies were used to simulate UV photoelectron spectra. We also calculated 1st adiabatic ionization energies for these CWA. Our results, especially 1st ionization energies (vertical and adiabatic) may be useful when applying photoionization techniques as part of hyphenated methods for detection and identification of CWA. The variations of vertical ionization energies were rationalized by the analysis of the electronic structure of CWA. The influence of electronic structures on toxicological properties is also discussed on the basis of calculated Hirshfeld type charges. •Electronic structures of chemical warfare agents (CWA).•Simulated UV photoelectron spectra of CWA.•Calculations of 1st adiabatic and valence ionization energies.•Relationship between electronic structures and relative toxicities of CWA.