Rotational Spectrum, Conformational Composition, Intramolecular Hydrogen Bonding, and Quantum Chemical Calculations of Mercaptoacetonitrile (HSCH2C≡N), a Compound of Potential Astrochemical Interest

Photochemistry of XCH2CN (X = -Cl, -SH) in Argon Matrices

We report infrared spectra and photochemical behavior of the potentially astrochemically significant species, mercaptoacetonitrile (HS-CH₂C≡N) and, for comparison purposes, chloroacetonitrile (Cl-CH₂C≡N), both suspended in an argon matrix at 6 K. Photolytic formation of the isocyano products HS-CH₂-NC and Cl-CH₂-NC were observed as well as CH₃NSC and CH₃SCN (in HS-CH₂CN photolysis). While no dissociation products were observed for Cl-CH₂-CN, photolysis of HS-CH₂-CN produced compounds necessitating the loss of the CN group to form CH₂═S, the SH group to form H₂C-CN and HC-CN, or both CN and SH to form CH₃ and CH₄. Observation of emission spectra upon annealing indicates the presence of free sulfur atom in matrices of photolyzed HS-CH₂-CN.

Proton-induced collision dynamics on potential prebiotic sulfur species

The formation of the building blocks of life and how they could survive under harsh astrophysical environments remains an open question of prebiotic chemistry. Effectively, ion bombardments or intense UV radiation may drive the destruction of prebiotic compounds. The possible role of sulfur in such processes is addressed here for the first time, by comparing directly proton-induced charge transfer for sulfur containing molecules and that for related COMs. The proton collision on mercaptoacetonitrile HSCH2C[triple bond, length as m-dash]N conformers has thus been investigated theoretically in a wide impact energy range modelling various astrophysical environments and compared to related COMs, namely HCN oligomers, in order to exhibit qualitative tendencies.