Crystal structure, Hirshfeld surface analysis and interaction energy and DFT studies of 2-chloroethyl 2-oxo-1-(prop-2-yn-1-yl)-1,2-dihydroquinoline-4-carboxylate

The title compound, C15H12ClNO3, consists of a 1,2-dihydroquinoline-4-carboxylate unit with 2-chloroethyl and propynyl substituents, where the quinoline moiety is almost planar and the propynyl substituent is nearly perpendicular to its mean plane. In the crystal, the molecules form zigzag stacks along the alpha-axis direction through slightly offset pi-stacking interactions between inversion-related quinoline moieties which are tied together by intermolecular C-H-Prpnyl center dot center dot center dot O-Carbx and C-H-Chlethy center dot center dot center dot O-Carbx (Prpnyl = propynyl, Carbx = carboxylate and Chlethy = chloroethyl) hydrogen bonds. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H center dot center dot center dot H (29.9%), H center dot center dot center dot O/O center dot center dot center dot H (21.4%), H center dot center dot center dot C/C center dot center dot center dot H (19.4%), H center dot center dot center dot Cl/Cl center dot center dot center dot H (16.3%) and C center dot center dot center dot C (8.6%) interactions. Hydrogen bonding and van der Waals interactions are the dominant interactions in the crystal packing. Computational chemistry indicates that in the crystal, the C-H-Prpnyl center dot center dot center dot O-Carbx and C-H-Chlethy center dot center dot center dot O-Carbx hydrogen bond energies are 67.1 and 61.7 kJ mol(-1) , respectively. 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.