Crystal structure, Hirshfeld surface analysis and DFT study of (2Z)-2-(4-fluorobenzylinene)-4-(prop-2-yn-1-yl)-3,4-dihydro-2H-1,4-Denzothiazin-3-one

Hni B., Sebbar N. K. , HÖKELEK T., Ouzidan Y., Moussaif A., Mague J. T. , ...More

ACTA CRYSTALLOGRAPHICA SECTION E-CRYSTALLOGRAPHIC COMMUNICATIONS, vol.75, pp.372-382, 2019 (Peer-Reviewed Journal) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 75
  • Publication Date: 2019
  • Doi Number: 10.1107/s2056989019002354
  • Journal Indexes: Emerging Sources Citation Index, Scopus
  • Page Numbers: pp.372-382


The title compound, C18H12FNOS, is built up from a 4-fluorobenzylidene moiety and a dihydrobenzothiazine unit with a propynyl substituent, with the heterocyclic portion of the dihydrobenzothiazine unit adopting a shallow boat conformation with the propynyl substituent nearly perpendicular to it. The two benzene rings are oriented at a dihedral angle of 43.02 (6)degrees. In the crystal, C- H-Flurphen center dot center dot center dot F-Flurphen (Flurphen = fluorophenyl) hydrogen bonds link the molecules into inversion dimers, enclosing R-2(2)(8) ring motifs, with the dimers forming oblique stacks along the a-axis direction. 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 (33.9%), H center dot center dot center dot C/C center dot center dot center dot H (26.7%), H center dot center dot center dot F/F center dot center dot center dot H (10.9%) and C center dot center dot center dot C (10.6%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in the crystal packing. 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.