Abstract
The title compound, C(18)H(12)Cl(2)N(2)OS, consists of a di-hydro-benzo-thia-zine unit linked by a -CH group to a 2,4-di-chloro-phenyl substituent, and to a propane-nitrile unit is folded along the S⋯N axis and adopts a flattened-boat conformation. The propane-nitrile moiety is nearly perpendicular to the mean plane of the di-hydro-benzo-thia-zine unit. In the crystal, C-H(Bnz)⋯N(Prpnit) and C-H(Prpnit)⋯O(Thz) (Bnz = benzene, Prpnit = propane-nitrile and Thz = thia-zine) hydrogen bonds link the mol-ecules into inversion dimers, enclosing R (2) (2)(16) and R (2) (2)(12) ring motifs, which are linked into stepped ribbons extending along [110]. The ribbons are linked in pairs by complementary C=O⋯Cl inter-actions. π-π contacts between the benzene and phenyl rings, [centroid-centroid distance = 3.974 (1) Å] may further stabilize the structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (23.4%), H⋯Cl/Cl⋯H (19.5%), H⋯C/C⋯H (13.5%), H⋯N/N⋯H (13.3%), C⋯C (10.4%) and H⋯O/O⋯H (5.1%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Computational chemistry calculations indicate that the two independent C-H(Bnz)⋯N(Prpnit) and C-H(Prpnit)⋯O(Thz) hydrogen bonds in the crystal impart about the same energy (ca 43 kJ mol(-1)). Density functional theory (DFT) optimized structures at the B3LYP/6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.