Crystal structure, Hirshfeld surface analysis and DFT studies of ethyl 2-{4-[(2-eth-oxy-2-oxoeth-yl)(phen-yl)carbamo-yl]-2-oxo-1,2-di-hydro-quinolin-1-yl}acetate.

The title com-pound, CHNO, consists of ethyl 2-(1,2,3,4-tetra-hydro-2-oxo-quinolin-1-yl)acetate and 4-[(2-eth-oxy-2-oxoeth-yl)(phen-yl)carbomoyl] units, where the oxo-quinoline unit is almost planar and the acetate substituent is nearly perpendicular to its mean plane. In the crystal, C-H⋯O and C-H⋯O (Oxqn = oxoquinolin, Ethx = eth-oxy, Phyl = phenyl and Carbx = carboxyl-ate) weak hydrogen bonds link the mol-ecules into a three-dimensional network sturucture. A π-π inter-action between the constituent rings of the oxo-quinoline unit, with a centroid-centroid distance of 3.675 (1) Å may further stabilize the structure. Both terminal ethyl groups are disordered over two sets of sites. The ratios of the refined occupanies are 0.821 (8):0.179 (8) and 0.651 (18):0.349 (18). The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (53.9%), H⋯O/O⋯H (28.5%) and H⋯C/C⋯H (11.8%) inter-actions. Weak inter-molecular hydrogen-bond inter-actions and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Density functional theory (DFT) geometric optimized structures at the B3LYP/6-311G(d,p) level are com-pared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO mol-ecular orbital behaviour was elucidated to determine the energy gap.