title: 2-{(E)-1-[2-(4-Nitro-phen-yl)hydrazin-1-yl-idene]eth-yl}benzene-1,3-diol.
abstract: The title compound, C(14)H(13)N(3)O(4), is close to planar, the dihedral angle between the terminal benzene rings being 5.80 (16)°; the nitro group is coplanar with the benzene ring to which it is bonded [O-N-C-C torsion angle = -177.3 (3)°]. The hy-droxy group forms an intra-molecular hydrogen bond with the imine N atom, and the conformation about the imine bond is E. In the crystal, layers in the (101) plane with an undulating topology are formed by O-H⋯O and N-H⋯O hydrogen bonds along with C-H⋯O inter-actions. Centrosymmetrically related layers are connected via π-π inter-actions [ring centroid-centroid distance = 3.5739 (19) Å] into double layers.
authors.forename: R Alan
authors.initials: RA
authors.lastname: Howie
authors.forename: James L
authors.initials: JL
authors.lastname: Wardell
authors.forename: Solange M S V
authors.initials: SM
authors.lastname: Wardell
authors.forename: Edward R T
authors.initials: ER
authors.lastname: Tiekink