2,4-Dihydr-oxy-N'-(4-methoxy-benzyl-idene)benzohydrazide

Experimental and computational evidence for stabilising parallel, offset π[C(O)N(H)NC]⋯π(phenyl) interactions in acetohydrazide derivatives

Stabilising π[C(O)N(H)NC]⋯π(phenyl) interactions are described.

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.

(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).

(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)-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.

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.