title: (E)-1-[(2-Amino-5-nitro-phen-yl)iminio-meth-yl]naphthalen-2-olate.
abstract: The title Schiff base compound, C(17)H(13)N(3)O(3), crystallizes in a zwitterionic form and exists in a trans configuration about the C=N bond. The mol-ecule is slightly twisted, the dihedral angle between the benzene ring and naphthalene ring system being 10.80 (9)°. The nitro group is twisted relative to the plane of the benzene ring [dihedral angle = 8.88 (12)°]. Bifurcated intra-molecular N-H⋯N and N-H⋯O hydrogen bonds formed between iminium groups and amine N atoms and naphthalen-2-olate O atoms generate S(5) and S(6) ring motifs, respectively. In the crystal, neighbouring zwitterions are linked through weak C-H⋯O inter-actions, giving rise to screw chains along [010]. Mol-ecules in these chains are linked to those of an adjacent chains through N-H⋯O hydrogen bonds and weak C-H⋯O inter-actions, forming sheets parallel to the ac plane. O⋯C [2.895 (3) Å] short contacts and π-π inter-actions [centroid-centroid distance = 3.8249 (19) Å] are also observed.
authors.forename: Abeer Mohamed
authors.initials: AM
authors.lastname: Farag
authors.forename: Siang Guan
authors.initials: SG
authors.lastname: Teoh
authors.forename: Hasnah
authors.initials: H
authors.lastname: Osman
authors.forename: Suchada
authors.initials: S
authors.lastname: Chantrapromma
authors.forename: Hoong-Kun
authors.initials: HK
authors.lastname: Fun