Crystal structure, Hirshfeld surface analysis, interaction energy and DFT calculations and energy frameworks of methyl 6-chloro-1-methyl-2-oxo-1,2-dihydroquinoline-4-carboxylate

Abstract

In the title compound, C12H10ClNO3, the dihydroquinoline moiety is not planar with a dihedral angle between the two ring planes of 1.61 (6)°. An intramolecular C—H...O hydrogen bond helps to establish the rotational orientation of the carboxyl group. In the crystal, sheets of molecules parallel to (10\overline{1}) are generated by C—H...O and C—H...Cl hydrogen bonds, and are stacked through slipped π-stacking interactions between inversion-related dihydroquinoline units. A Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (34.2%), H...O/O...H (19.9%), H...Cl/Cl...H (12.8%), H...C/C...H (10.3%) and C...C (9.7%) interactions. Computational chemistry indicates that in the crystal, the C—H...Cl hydrogen-bond energy is −37.4 kJ mol−1, while the C—H...O hydrogen-bond energies are −45.4 and −29.2 kJ mol−1. An evaluation of the electrostatic, dispersion and total energy frameworks revealed that the stabilization is dominated via the dispersion energy contribution. 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, and the HOMO—LUMO behaviour was elucidated to determine the energy gap.

Keywords

• crystal structure
• hydrogen-bonding
• π-stacking
• dihydroquinoline