Crystal structure, Hirshfeld surface analysis and interaction energy and DFT studies of 4-[(prop-2-en-1-yloxy)methyl]-3,6-bis(pyridin-2-yl)pyridazine

The title compound, C 18 H 16 N 4 O, consists of a 3,6-bis(pyridin-2-yl)pyridazine moiety linked to a 4-[(prop-2-en-1-yloxy)methyl] group. The pyridine-2-yl rings are oriented at a dihedral angle of 17.34 (4)° and are rotated slightly out of the plane of the pyridazine ring. In the crystal, C—H Pyrd ...N Pyrdz (Pyrd = pyridine and Pyrdz = pyridazine) hydrogen bonds and C—H Prpoxy ...π (Prpoxy = prop-2-en-1-yloxy) interactions link the molecules, forming deeply corrugated layers approximately parallel to the bc plane and stacked along the a -axis direction. Hirshfeld surface analysis indicates that the most important contributions for the crystal packing are from H...H (48.5%), H...C/C...H (26.0%) and H...N/N...H (17.1%) contacts, hydrogen bonding and van der Waals interactions being the dominant interactions in the crystal packing. Computational chemistry indicates that in the crystal, the C—H Pyrd ...N Pyrdz hydrogen-bond energy is 64.3 kJ mol −1 . 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.