title: Structural flexibility of the sulfur mustard molecule at finite temperature from Car-Parrinello molecular dynamics simulations.
abstract: Sulfur mustard (SM) is one of the most dangerous chemical compounds used against humans, mostly at war conditions but also in terrorist attacks. Even though the sulfur mustard has been synthesized over a hundred years ago, some of its molecular properties are not yet resolved. We investigate the structural flexibility of the SM molecule in the gas phase by Car-Parrinello molecular dynamics simulations. Thorough conformation analysis of 81 different SM configurations using density functional theory is performed to analyze the behavior of the system at finite temperature. The conformational diversity is analyzed with respect to the formation of intramolecular blue-shifting CH⋯S and CH⋯Cl hydrogen bonds. Molecular dynamics simulations indicate that all structural rearrangements between SM local minima are realized either in direct or non-direct way, including the intermediate structure in the last case. We study the lifetime of the SM conformers and perform the population analysis. Additionally, we provide the anharmonic dynamical finite temperature IR spectrum from the Fourier Transform of the dipole moment autocorrelation function to mimic the missing experimental IR spectrum.
authors.affiliation: Department of General Physics and Spectroscopy, Vilnius University, Sauletekio av. 3-9, Vilnius 10222, Lithuania.
authors.forename: Joanna
authors.initials: J
authors.lastname: Lach
authors.affiliation: Interdisciplinary Center for Molecular Materials (ICMM) and Computer-Chemistry-Center (CCC), Friedrich-Alexander-University Erlangen-Nürnberg, Nägelsbachstr. 25, 91052 Erlangen, Germany.
authors.forename: Jakub
authors.initials: J
authors.lastname: Goclon
authors.affiliation: Institute of Chemistry, University of Bialystok, Hurtowa 1, 15-399 Bialystok, Poland. Electronic address: pawel.rodziewicz@fau.de.
authors.forename: Pawel
authors.initials: P
authors.lastname: Rodziewicz
keywords: Bis(2-chloroethyl) sulfide; Car–Parrinello molecular dynamics; Density functional theory; IR spectrum; Mustard gas; S-LOST; Sulfur mustard; Yperite