(E)-N′-(3,5-Dibromo-2-hydroxy­benzyl­idene)-2-nitro­benzohydrazide methanol solvate

In the title compound, C14H9Br2N3O4·CH3OH, the Schiff base mol­ecule adopts an E geometry with respect to the C=N bond and the benzene rings are oriented at a dihedral angle of 45.3 (2)°. An intra­molecular O—H⋯N hydrogen bond helps to establish the conformation. In the crystal, the methanol solvent mol­ecule is linked to the Schiff base mol­ecule through an O—H⋯O hydrogen bond and inter­molecular N—H⋯O hydrogen bonds link the components to form layers parallel to the bc direction

4,4′-(Propane-1,3-di­yl)dipyridinium tetra­chloridonickelate(II)

The title compound, (C13H16N2)[NiCl4] or (H2bpp)·NiCl4 [bpp is 1,3-bis­(4-pyrid­yl)propane], is isostructural with its already reported Cu, Zn and Hg analogues. The structure consists of a doubly charged (H2bpp)2+ cation and a tetra­hedral [NiCl4]2− dianion. Both pyridyl N atoms are protonated and form a (H2bpp)2+ cation which adopts an anti–anti conformation with a dihedral angle of 6.287 (7)° between the pyridyl rings. The two pyridyl N atoms are both involved in strong N—H⋯Cl hydrogen bonds, which link both units into a dimer

(E)-N′-(5-Chloro-2-hydroxy­benzyl­idene)-2-nitro­benzohydrazide

In the title Schiff base compound, C14H10ClN3O4, the mol­ecule adopts an E geometry with respect to the C=N bond and an intra­molecular O—H⋯N hydrogen bond is present. The benzene rings form a dihedral angle of 73.4 (2)°. In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds occur