Crystal structure, Hirshfeld surface analysis and DFT calculations of (E)-3-[1-(2-hy­droxy­phenyl­anilino)ethyl­idene]-6-methyl­pyran-2,4-dione

The asymmetric unit of the title compound, C(14)H(13)NO(4), contains three independent mol­ecules, which differ slightly in conformation. Each contains an intra­molecular N—H⋯O hydrogen bond. In the crystal, O—H⋯O hydrogen bonds form chains of mol­ecules, which are linked into corrugated sheets parallel to ( [Image: see text] 03) plane by C—H⋯O hydrogen bonds together with π inter­actions between the carbonyl groups and the 2-hy­droxy­phenyl rings. The layers are linked by further C—H⋯O hydrogen bonds. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (49.0%), H⋯O/O⋯H (28.3%) and H⋯C/C⋯H (10.9%) inter­actions. van der Waals inter­actions are the dominant inter­actions in the crystal packing. Moreover, 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 behavior was elucidated to determine the energy gap of 4.53 eV.