Crystal structure, Hirshfeld surface analysis and interaction energy and DFT studies of methyl 4-[3,6-bis(pyridin-2-yl)pyridazin-4-yl]benzoate

The title compound, C 22 H 16 N 4 O 2 , contains two pyridine rings and one methoxycarbonylphenyl group attached to a pyridazine ring which deviates very slightly from planarity. In the crystal, ribbons consisting of inversion-related chains of molecules extending along the a -axis direction are formed by C—H Mthy ...O Carbx (Mthy = methyl and Carbx = carboxylate) hydrogen bonds. The ribbons are connected into layers parallel to the bc plane by C—H Bnz ...π(ring) (Bnz = benzene) interactions. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H...H (39.7%), H...C/C...H (27.5%), H...N/N...H (15.5%) and O...H/H...O (11.1%) 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 Mthy ...O Carbx hydrogen-bond energies are 62.0 and 34.3 kJ mol −1 , respectively. Density functional theory (DFT) optimized structures at the B3LYP/6-311G(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.