Crystal structure and Hirshfeld surface analysis of 1-[(E)-2-(3-nitrophenyl)diazen-1-yl]naphthalen-2-ol

Abstract

The title compound, C16H11N3O3, belongs to the family of azo dyes. In the light of a single-crystal X-ray study, it is evident that of the tautomeric forms (azo–hydrazone), the hydrazone form is the predominant form in the solid state, namely, (1E)-1-[2-(3-nitrophenyl)hydrazin-1-ylidene]-1,2-dihydronaphthalen-2-one. The naphthol and benzene fragments attached to the –N=N– moiety adopt the s-trans conformation. Furthermore, the molecules are nearly coplanar, subtending a dihedral angle of 2.63 (5)°. An intramolecular N—H...O hydrogen bond occurs. There are only two types of intermolecular interactions in the crystal structure: strong hydrogen-bonding C—H...O interactions and π–π stacking interactions. The importance of C—H...O interactions in the molecular packing is reflected by the relatively high contributions (28.5%) made by O...H/H...O contacts to the Hirshfeld surface.