A new polymorph of N-(2-{N'-[(1E)-2hydroxybenzylidene]hydrazinecarbonyl}phenyl)benzamide

The title compound, C21H17N3O3, is a new polymorph of an already published structure [Shashidhar et al. (2006). Acta Cryst. E62, o4473-o4475]. The previously reported structure crystallizes in the monoclinic space group C2/c, whereas the structure reported here is in the tetragonal space group I41/a. The bond lengths and angles are similar in both structures. The molecule adopts an extended conformation via intramolecular N-H center dot center dot center dot O and O-H center dot center dot center dot N hydrogen bonds; the terminal phenyl ring and the hydroxylphenyl ring are twisted with respect to the central benzene ring by 44.43 (7) and 21.99 (8)degrees, respectively. In the crystal, molecules are linked by N-H center dot center dot center dot O hydrogen bonds, weak C-H center dot center dot center dot O hydrogen bonds and weak C-H center dot center dot center dot pi interactions into a three-dimensional supramolecular network.