(E)-4-Amino-N′-(2-nitro­benzyl­idene)benzohydrazide

The title Schiff base compound, C14H12N4O3, displays an E conformation with respect to the C=N double bond [1.268 (3) Å]. The dihedral angle between the benzene rings is 3.2 (5)°, consistent with an essentially planar mol­ecule. In the crystal, N—H⋯O and N—H⋯N hydrogen bonds, as well as C—H⋯O inter­actions, link the mol­ecules into layers that stack along the c axis

2-{[3-Methyl-4-(2,2,2-trifluoro­eth­oxy)pyridin-2-yl]methyl­sulfan­yl}-1H-benzimidazole monohydrate

The asymmetric unit of the title compound, C16H14F3N3OS·H2O, contains two independent mol­ecules (A and B) and two water mol­ecules, one of which is disordered over two positions in a 0.790 (8):0.210 (8) ratio. The mol­ecular conformations are close, the benzimidazole mean plane and pyridine ring forming dihedral angles of 1.8 (3) and 0.1 (2)° in mol­ecules A and B, respectively. The water mol­ecules are involved in formation of two independent hydrogen-bonded chains via N—H⋯O and O—H⋯N hydrogen bonds. Chains propagating along the a axis are formed by mol­ecule A and one independent water mol­ecule, while chains propagating along the b axis are formed by mol­ecule B and the other independent water mol­ecule. The crystal packing exhibits π–π inter­actions, as indicated by short distances of 3.607 (3) and 3.701 (3) Å between the centroids of the imidazole and pyridine rings of neighbouring mol­ecules

(E)-4-Amino-N′-(5-chloro-2-hy­droxy­benzyl­idene)benzohydrazide

The title compound, C14H12ClN3O2, displays an E conformation with respect to the C=N double bond. The dihedral angle between the benzene rings is 41.3 (5)°. The mol­ecular structure is stabilized by an intra­molecular O—H⋯N hydrogen bond. In the crystal, N—H⋯O and weak N—H⋯Cl hydrogen bonds link the mol­ecules into a three-dimensional architecture. In addition, there are weak C—H⋯π stacking inter­actions

1,3-Dihy­droxy-2-(hy­droxy­meth­yl)propan-2-aminium formate

The title compound, C4H12NO3 +·CHO2 −, was obtained from 1,3-dihy­droxy-2-(hy­droxy­meth­yl)propan-2-aminium acetate and ethyl formate. In the crystal, the cations and anions are held together by inter­molecular N—H⋯O and O—H⋯O hydrogen bonds