Crystal structure of (E)-N′-(3,4-dihydroxybenzylidene)-4-hydroxybenzohydrazide

Abstract

In the title benzohydrazide derivative, C14H12N2O4, the azomethine C=N double bond has an E configuration. The hydrazide connecting bridge, (C=O)—(NH)—N=(CH), is nearly planar with C—C—N—N and C—N—N=C torsion angles of −177.33 (10) and −174.98 (12)°, respectively. The 4-hydroxyphenyl and 3,4-dihydroxyphenyl rings are slightly twisted, making a dihedral angle of 9.18 (6)°. In the crystal, molecules are connected by N—H...O and O—H...O hydrogen bonds into a three-dimensional network, while further consolidated via π–π interactions [centroid–centroid distances = 3.6480 (8) and 3.7607 (8) Å]. The conformation is compared to those of related benzylidene-4-hydroxybenzohydrazide derivatives.