N'-(3-Bromo-5-chloro-2-hy-droxy-benzyl-idene)-2H-1,3-benzodioxole-5-carbo-hydrazide.

The asymmetric unit of the title hydrazone compound, C(15)H(10)BrClN(2)O(4), contains two independent mol-ecules. The dihedral angles between the benzene rings are 38.7 (3)° in one mol-ecule and 24.3 (3)° in the other. Both mol-ecules exist in trans conformations with respect to the C=N double bonds of the central methyl-idene units. Intra-molecular O-H⋯N contacts are observed in both mol-ecules, forming S(6) rings. In the crystal, mol-ecules are linked through N-H⋯O hydrogen bonds into chains along the a axis.

(E)-N'-(5-Bromo-2-meth-oxy-benzyl-idene)isonicotinohydrazide.

The asymmetric unit of the title compound, C(14)H(12)BrN(3)O(2), contains two independent mol-ecules in which the dihedral angles between the benzene ring and the pyridine ring are 24.4 (6) and 23.7 (6)°. The mol-ecules exist in a trans configuration with respect to the central methyl-idene units. In the crystal, mol-ecules are linked through inter-molecular N-H⋯O hydrogen bonds, forming chains along the a axis.

(E)-2-Fluoro-N'-(4-nitro-benzyl-idene)benzo-hydrazide.

In the title hydrazone compound, C(14)H(10)FN(3)O(3), the dihedral angle between the two substituted benzene rings is 13.7 (3)°. The mol-ecule exists in a trans configuration with respect to the central methyl-idene unit. In the crystal, mol-ecules are linked through inter-molecular N-H⋯O hydrogen bonds, forming chains along the a axis.

(E)-4-Meth-oxy-N'-(4-nitro-benzyl-idene)benzohydrazide methanol monosolvate.

The hydrazone mol-ecule of the title compound, C(15)H(13)N(3)O(4)·CH(4)O, is nearly planar, with a dihedral angle between the two benzene rings of 1.2 (4)°. The mol-ecule exists in a trans configuration with respect to the central methyl-idene unit. In the crystal, the benzohydrazide and methanol mol-ecules are linked through inter-molecular O-H⋯O, O-H⋯N and N-H⋯O hydrogen bonds, forming chains along the a axis.

(E)-2-Meth-oxy-N'-(4-nitro-benzyl-idene)benzohydrazide.

In the title compound, C(15)H(13)N(3)O(4), the mol-ecule exists in a trans configuration with respect to the methyl-idene unit. The dihedral angle between the two benzene rings is 6.8 (2)°. The C-N-NH-C torsion angle is 3.4 (3)°. The mol-ecule possesses an intra-molecular N-H⋯O hydrogen bond. In the crystal structure, adjacent mol-ecules are linked through inter-molecular C-H⋯O hydrogen bonds, forming dimers.

(E)-N'-[1-(2-Hydroxy-phen-yl)ethyl-idene]-3-methoxy-benzohydrazide.

In the title compound, C(16)H(16)N(2)O(3), the benzohydrazide group is not planar and the mol-ecule exists in a trans configuration with respect to the methyl-idene unit. The dihedral angle between the two substituted benzene rings is 26.9 (2)°. In the crystal structure, the mol-ecular packing is stabilized by intra-molecular O-H⋯N and inter-molecular N-H⋯O hydrogen bonds. The inter-molecular hydrogen bonding forms chains parallel to the b axis.

(E)-N'-(5-Bromo-2-methoxy-benzyl-idene)-3-methoxy-benzohydrazide.

In the title compound, C(16)H(15)BrN(2)O(3), there are two independent mol-ecules (A and B) in the asymmetric unit. The major difference between the two mol-ecules is the dihedral angle formed by the aromatic rings [72.6 (2) and 18.8 (2)° for A and B, respectively]. The benzohydrazide groups are not planar and the mol-ecules exist in trans configurations with respect to the methyl-idene units. The mol-ecular packing is stabilized by two inter-molecular N-H⋯O hydrogen bonds, forming chains parallel to the c axis. Only the A mol-ecules of the asymmetric unit are held together by π-π inter-actions [centroid-centroid distance = 3.714 (3) Å].

(E)-N'-(4-Hydroxy-benzyl-idene)-4-hydroxy-benzohydrazide methanol solvate.

The title compound, C(14)H(12)N(2)O(3)·CH(4)O, consists of a Schiff base mol-ecule and a methanol mol-ecule of crystallization. The Schiff base mol-ecule is nearly planar, the dihedral angle between the planes of the two benzene rings being 7.2 (2)°. The mol-ecule exists in the trans configuration with respect to the methyl-idene unit. In the crystal structure, the Schiff base and methanol mol-ecules are linked through O-H⋯O, N-H⋯O and O-H⋯N hydrogen bonds, forming a three-dimensional network.

(E)-4-Hydr-oxy-N'-(4-nitro-benzyl-idene)benzohydrazide.

The mol-ecule of the title compound, C(14)H(11)N(3)O(4), is approximately planar, the dihedral angle between the planes of the two substituted benzene rings being 2.54 (7)°. The mol-ecule exists in a trans configuration with respect to the central methyl-idene unit. In the crystal structure, mol-ecules are linked through inter-molecular O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds, forming layers parallel to (101). The O/N-H⋯O and C-H⋯O inter-actions form a pair of bifurcated acceptor bonds involving the cabon-yl/nitro O atom, generating an R(2) (1)(6) motif.

(E)-N'-(2-Chloro-5-nitro-benzyl-idene)-4-methoxy-benzohydrazide.

In the title compound, C(15)H(12)ClN(3)O(4), the benzohydrazide group is not planar and the mol-ecule exists in a trans configuration with respect to the methyl-idene unit. The dihedral angle between the two substituted benzene rings is 0.4 (3)°. In the crystal structure, mol-ecules are linked by inter-molecular N-H⋯O hydrogen bonds, forming chains parallel to the c axis.

(E)-N'-(5-Bromo-2-methoxy-benzyl-idene)-4-methoxy-benzohydrazide.

In the title compound, C(16)H(15)BrN(2)O(3), the benzohydrazide group is not planar and the mol-ecule exists in a trans configuration with respect to the methyl-idene unit. The dihedral angle between the two substituted benzene rings is 75.6 (2)°. In the crystal structure, mol-ecules are linked by inter-molecular N-H⋯O hydrogen bonds involving carbonyl and amine functionalities, to form chains parallel to the c cell axis.