Structures of Trichloromethyl Thiocyanate, CCl 3 SCN, in Gaseous and Crystalline State

Abstract

Trichloromethyl thiocyanate, CCl3SCN, was structurally studied in both the gas and crystal phases by means of gas electron diffraction (GED) and single-crystal X-ray diffraction (XRD), respectively. Both experimental studies and quantum chemical calculations indicate a staggered orientation of the CCl3 group relative to the SCN group. This conclusion is supported by the similarity of the C-SCN bond length to that of the anti-structure of CH2ClSCN (Berrueta Martínez et al. Phys. Chem. Chem. Phys. 2015, 17, 15805-15812). Bond lengths and angles are similar for gas and crystal CCl3SCN structures; however, the crystal structure presents different intermolecular interactions. These include halogen and chalcogen type interactions, the geometry of which was studied. Characteristic C-Y⋯N angles (Y=Cl or S) close to 180° provide evidence for typical σ-hole interactions along the halogen/chalcogen-carbon bond in N⋯Cl and N⋯S, intermolecular units. Crystallize the difference: The crystal and gas-phase structures of CCl3SCN are studied by X-ray and gas electron diffraction techniques. In both phases, the CCl3 group presents a staggered orientation relative to the SCN group. Different intermolecular interactions are detected in the solid phase, including halogen- and chalcogen-type interactions.