Crystal structure, Hirshfeld surface analysis and interaction energy, DFT and antibacterial activity studies of ethyl 2-[(2Z)-2-(2-chlorobenzylidene)-3-oxo-3,4-dihydro-2H-1,4-benzothiazin-4-yl]acetate

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Sebbar G., Mohamed E., HÖKELEK T., Mague J. T., Sebbar N. K., Essassi E. M., ...More

ACTA CRYSTALLOGRAPHICA SECTION E-CRYSTALLOGRAPHIC COMMUNICATIONS, vol.76, pp.629-642, 2020 (ESCI) identifier identifier identifier


The title compound, C19H16ClNO3S, consists of chlorophenyl methylidene and dihydrobenzothiazine units linked to an acetate moiety, where the thiazine ring adopts a screw-boat conformation. In the crystal, two sets of weak C-HPh center dot center dot center dot ODbt (Ph = phenyl and Dbt = dihydrobenzothiazine) hydrogen bonds form layers of molecules parallel to the bc plane. The layers stack along the aaxis direction with intercalation of the ester chains. The crystal studied was a two component twin with a refined BASF of 0.34961 (5). The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions to the crystal packing are from H center dot center dot center dot H (37.5%), H center dot center dot center dot C/C center dot center dot center dot H (24.6%) and H center dot center dot center dot O/O center dot center dot center dot H (16.7%) interactions. Hydrogen-bonding and van der Waals interactions are the dominant interactions in the crystal packing. Computational chemistry indicates that in the crystal, C-H-Ph center dot center dot center dot O-Dbt hydrogen bond energies are 38.3 and 30.3 kJ mol(-1). Density functional theory (DFT) optimized structures at the B3LYP/ 6-311 G(d,p) level are compared with the experimentally determined molecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap. Moreover, the antibacterial activity of the title compound has been evaluated against gram-positive and gram-negative bacteria.