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.

Crystal structure, Hirshfeld surface analysis and energy frameworks of 1-[(E)-2-(2-fluorophenyl)diazan-1-ylidene]naphthalen-2(1H)-one

“…The N19-N20 [1.310 (2) A ˚] and C8-O17 [1.264 (3) A ˚] bond lengths indicate that the compound adopts the neutral hydrazo tautomer form upon crystallization. This is common when an OH group is in the ortho-position relative to the azo group, leading to a proton being transferred from the naphthol group to the azo group (Benaouida et al, 2023;Bougueria et al, 2021). The internal alternate angles at N19 and N20 are identical within experimental error with an average value of 118.25 (2) � .…”

“…A search of the Cambridge Structural Database (CSD; Version 2023.2.0, last update September 2023; Groom et al, 2016) for 1-phenylazo-2-naphthol derivatives revealed that numerous azo-2-naphthol compounds with similar structures have been synthesized using various aromatic primary amines. Benosmane et al, 2013), 1-[(E)-2-(5-chloro-2 hydroxyphenyl) hydrazin-1-ylidene]naphthalen-2(1H)-one (UVIDOV; Bougueria et al, 2021), OGUXAP01, OGUXAP02 and OGUXAP03;Gilli et al, 2002), (E)-1-[2-(3-nitrophenyl)hydrazinylidene]naphthalen-2(1H)-one (FIFCEG; Benaouida et al, 2023), 1-(phenylazo)-2-naphthol (JARPEX; Olivieri et al, 2002), (Z)-1-(2-phenyldiazen-2-ium-1-yl)naphthalen-2-olate (TIFTEJ01; Benosmane et al, 2015). All these compounds belong to the azo dyes family and share a common base structure -a benzene ring and a naphthalene ring system linked with an oxygen in the ortho position relative to the azo group.…”