ACTA CRYSTALLOGRAPHICA SECTION E-CRYSTALLOGRAPHIC COMMUNICATIONS, vol.75, pp.892-900, 2019 (ESCI)
The title pyridazinone derivative, C21H19ClN2O3, is not planar. The unsubstituted phenyl ring and the pyridazine ring are inclined to each other, making a dihedral angle of 17.41 (13)degrees whereas the Cl-substituted phenyl ring is nearly orthogonal to the pyridazine ring [88.19 (13)degrees]. In the crystal, C-H center dot center dot center dot O hydrogen bonds generate dimers with R-2(2)(10) and R-2(2)(24) ring motifs which are linked by C-H center dot center dot center dot O interactions, forming chains extending parallel to the c-axis direction. The intermolecular interactions were investigated using Hirshfeld surface analysis and two-dimensional fingerprint plots, revealing that the most significant contributions to the crystal packing are from H center dot center dot center dot H (44.5%), C center dot center dot center dot H/H center dot center dot center dot C (18.5%), H center dot center dot center dot O/H center dot center dot center dot O (15.6%), Cl center dot center dot center dot H/H center dot center dot center dot Cl (10.6%) and C center dot center dot center dot C (2.8%) contacts.