A second monoclinic polymorph of 2-[2-(4-methoxyphenyl)hydrazinylidene]-1,3-diphenylpropane-1,3-dione

The title compound, C22H18N2O3 is the second monoclinic polymorph (P2(1)/c) of the compound, the first being reported in space group P2(1) [Bertolasi et al. (1993). J. Chem. Soc. Perkin Trans. 2, pp. 2223-2228]. In the molecular structure of the title compound, the interplanar angle between the benzoyl units is 80.04 (5)degrees, while the corresponding angles between the phenylhydrazinylidene and benzoyl groups are 36.11 (5) and 55.77 (2)degrees. A strong resonance-assisted intramolecular N-H center dot center dot center dot O hydrogen bond is found. In the crystal, the entire supramolecular structure is constructed by weak intermolecular C-H center dot center dot center dot O interactions and an inter-ring pi-pi interaction [centroid-centroid distance = 3.6088 (8) angstrom].