3,5-Dihydr-oxy-N'-[(2-hydr-oxy-1-naph-thyl)methyl-ene]benzohydrazide

2-Chloro-N'-(2-hy-droxy-3,5-diiodo-benzyl-idene)benzohydrazide

In the title compound, C(14)H(9)ClI(2)N(2)O(2), the dihedral angle between the benzene rings is 65.9 (2)° and an intra-molecular O-H⋯N hydrogen bond generates an S(6) ring. The mol-ecule has an E conformation about the C=N bond. In the crystal, mol-ecules are linked into C(4) chains propagating in [001] by N-H⋯O hydrogen bonds.

(E)-N'-(3,4-Dimethoxy-benzyl-idene)-2,4-dihydroxy-benzohydrazide methanol solvate

The title compound, C₁₆H₁₆N₂O₅·CH₃OH, was obtained from a condensation reaction of 3,4-dimethoxy­benzaldehyde and 2,4-dihydroxy­benzohydrazide. The non-H atoms of the Schiff base mol­ecule are approximately coplanar (r.m.s. deviation = 0.043 Å) and the dihedral angle between the two benzene rings is 1.6 (1)°. The mol­ecule adopts an E configuration with respect to the C=N double bond. An intra­molecular O—H⋯O hydrogen bond is observed. The Schiff base and methanol mol­ecules are linked into a two-dimensional network parallel to (10) by inter­molecular N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds.

2,4-Dihydr-oxy-N'-(3,4,5-trimethoxy-benzyl-idene)benzohydrazide

In the title compound, C₁₇H₁₈N₂O₆, the mol­ecule is slightly twisted, with a dihedral angle of 18.1 (2)° between the two benzene rings. In the crystal structure, mol­ecules are linked into a network by inter­molecular N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds. An intra­molecular O—H⋯O hydrogen bond is also present.

(E)-N'-(3,4-Dihydroxy-benzyl-idene)-4-nitro-benzohydrazide

In the title Schiff base compound, C₁₄H₁₁N₃O₅, the dihedral angle between the two benzene rings is 1.6 (1)°. The mol­ecule displays an E configuration about the C=N bond. An intra­molecular O—H⋯O hydrogen bond is observed. In the crystal, mol­ecules are linked into layers parallel to (101) by O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds. One of the hydroxyl groups is disordered over two positions, with occupancies of 0.643 (5) and 0.357 (5).

N'-(5-Chloro-2-hydroxy-benzyl-idene)-4-hydroxy-benzohydrazide

The title Schiff base compound, C(14)H(11)ClN(2)O(3), was prepared by the reaction of 5-chloro-salicylaldehyde and 4-hydroxy-benzohydrazide. The mol-ecule exists in a trans configuration with respect to the methyl-idene group. The dihedral angle between the two benzene rings is 40.1 (2)°. An intra-molecular O-H⋯N hydrogen bond helps to stabilize the mol-ecular conformation. In the crystal structure, mol-ecules are linked into a three-dimensional network by inter-molecular N-H⋯O and O-H⋯O hydrogen bonds.

(E)-4-Bromo-N'-(2-nitro-benzyl-idene)benzohydrazide

The title compound, C(14)H(10)BrN(3)O(3), was obtained by a condensation reaction between 2-nitro-benzaldehyde and 4-bromo-benzohydrazide. The dihedral angle between the two benzene rings is 4.1 (2)°. The mol-ecule displays an E configuration about the C=N bond. In the crystal, mol-ecules are linked into a chain along [100] by inter-molecular N-H⋯O hydrogen bonds.

(E)-4-Bromo-N′-(2-hydroxy-1-naphthylmethylene)benzohydrazide

The title compound, C₁₈H₁₃BrN₂O₂, was synthesized by the reaction of 2-hydr­oxy-1-naphthaldehyde with 4-bromo­benzohydrazide. This Schiff base mol­ecule has an E configuration about the C=N bond and is almost planar, the dihedral angle between the mean planes through the substituted benzene ring and the naphthyl system being 6.6 (2)°. There is an intra­molecular O—H⋯N hydrogen bond involving the naphthyl hydr­oxy substituent and the N′ atom of the hydrazide group. In the crystal structure, mol­ecules are linked through inter­molecular N—-H⋯O hydrogen bonds to form chains extending along the b direction.

(E)-2-Chloro-N'-(2-hydr-oxy-1-naphthyl-methyl-ene)benzohydrazide

In the structue of the title compound, C₁₈H₁₃ClN₂O₂, a new Schiff base, the dihedral angle between the benzene and naphthyl ring system mean planes is 22.5 (2)°. The mol­ecule has an E configuration about the C=N bond, and an intra­molecular hydrogen bond involving the hydoxyl substituent on the naphthyl ring and the N′ atom of the hydrazide. The crystal structure is stabilized by inter­molecular N—H⋯O hydrogen bonds, forming one-dimensional chains running parallel to the a axis.

2-Hydr-oxy-N'-(2-methoxy-naphthyl-idene)benzohydrazide

The title Schiff base compound, C(19)H(16)N(2)O(3), prepared by the reaction of 2-meth-oxy-1-naphthyl-aldehyde and 2-hydroxy-benzohydrazide, crystallizes with two independent mol-ecules in the asymmetric unit. Each mol-ecule exists in a trans configuration with respect to the methyl-idene group. The naphthyl ring system make dihedral angles of 65.0 (2)° and 55.8 (2)° with the planes of the benzene rings. Intra-molecular N-H⋯O and O-H⋯O hydrogen bonds help to stabilize the mol-ecular conformations. In the crystal structure, mol-ecules are linked into one-dimensional chains parallel to the c axis by inter-molecular O-H⋯N and O-H⋯O hydrogen bonds.

4-Meth-oxy-N'-(2-methoxy-naphthyl-idene)benzohydrazide

The mol-ecule of the title Schiff base compound, C(20)H(18)N(2)O(3), prepared by the reaction of 2-meth-oxy-1-naphthyl-aldehyde and 4-methoxy-benzohydrazide, exists in a trans configuration with respect to the imine group. The naphthyl ring system makes a dihedral angle of 71.4 (2)° with the mean plane of the benzene ring. In the crystal structure, mol-ecules are linked into one-dimensional chains parallel to the c axis by inter-molecular N-H⋯O hydrogen bonds.

N′-(2-Hydroxy-5-chlorobenzylidene)-4-nitrobenzohydrazide methanol solvate

The title compound, C₁₄H₁₀ClN₃O₄·CH₄O, was synthesized from the reaction of 5-chloro­salicylaldehyde with 4-nitro­benzohydrazide in methanol. The Schiff base mol­ecule is nearly planar, with a dihedral angle of 9.1 (3)° between the two benzene rings. The methanol solvent mol­ecules are linked to the Schiff base mol­ecules by N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds, forming chains running parallel to the a axis.

N'-(3-Eth-oxy-2-hydroxy-benzyl-idene)-3-hydroxy-naphthalene-2-carbohydrazide

In the mol­ecule of the title compound, C₂₀H₁₈N₂O₄, the dihedral angle between the benzene ring and the naphthyl ring system is 8.5 (2)°. In the crystal structure, mol­ecules are linked through inter­molecular O—H⋯O hydrogen bonds, forming chains running along the b axis.

N'-(4-Methoxy-benzyl-idene)-4-nitro-benzo-hydrazide methanol solvate

The title compound, C₁₅H₁₃N₃O₄·CH₄O, was synthesized from the reaction of 4-methoxy­benzaldehyde with 4-nitro­benzohydrazide in methanol. The benzene rings of the Schiff base mol­ecule are nearly coplanar, making a dihedral angle of 7.0 (3)°. The methanol solvent mol­ecules are linked to the Schiff base mol­ecules by N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds, forming chains running parallel to the b axis.