Crystal structure and Hirshfeld surface analysis of 6-(()-2-{4-[2-(4-chloro-phen-yl)-2-oxoeth-oxy]phen-yl}ethen-yl)-4,5-di-hydro-pyridazin-3(2)-one.

The pyridazine ring in the title compound, CHClNO, adopts a screw-boat conformation. The whole mol-ecule is flattened, the dihedral angles subtended by the least-squares plane of the central aromatic ring with those of the terminal benzene and pyridazine rings being 15.18 (19) and 11.