(E)-4-Hy­droxy-N′-(2-hy­droxy-3,5-diiodo­benzyl­idene)-3-meth­oxy­benzohydrazide methanol monosolvate

In the title compound, C₁₅H₁₂I₂N₂O₄·CH₃OH, the hydrazone mol­ecule exists in an E conformation with respect to the C=N bond. The dihedral angle between the rings is 11.9 (2)°. There is one intra­molecular O—H...N hydrogen bond in the hydrazone mol­ecule. In the crystal, the hydrazone and methanol mol­ecules are linked through O—H...O and N—H...O hydrogen bonds and C—H...O inter­actions to form two-dimensional networks lying parallel to (001).

(E)-4-Nitro-N′-(3-nitro­benzyl­idene)benzohydrazide

The title compound, C₁₄H₁₀N₄O₅, has an E conformation with respect to the C=N bond. The dihedral angle between the benzene rings is 2.41 (14)°. In the crystal, mol­ecules are linked through N—H...O hydrogen bonds to form chains along the c axis. C—H...O inter­actions are also present, linking the chains to form a three-dimensional network.

(E)-3-Nitro-N′-(3-nitro­benzyl­idene)­benzohydrazide

In the title compound, C₁₄H₁₀N₄O₅, the mol­ecule exists in a trans conformation with respect to the methyl­idene unit. The dihedral angle between the benzene rings is 9.8 (2)°. In the crystal, mol­ecules are linked through N—H...O hydrogen bonds to form chains along the c axis.

(E)-N′-(3-Fluoro­benzyl­idene)-3-nitro­benzohydrazide

In the title compound, C₁₄H₁₀FN₃O₃, the mol­ecule exists in a trans conformation with respect to the methyl­idene unit. The dihedral angle between the benzene rings is 5.1 (2)°. In the crystal, mol­ecules are linked through N—H...O hydrogen bonds, forming chains along the c axis.

(E)-2-Chloro-N′-(4-hy­droxy­benzyl­idene)­benzohydrazide

The title hydrazone mol­ecule, C₁₄H₁₁ClN₂O₂, has a trans conformation with respect to the methyl­idene unit. The dihedral angle between the two benzene rings is 37.6 (3)°. In the crystal, the presence of O—H...O, O—H...N and N—H...O hydrogen bonds leads to the formation of a three-dimensional network. The title compound crystallized in the chiral ortho­rhom­bic space group P2₁2₁2₁ and was refined as an inversion twin [Flack parameter = −0.20 (18)].

Ethyl 4-methyl-1,3-dioxo-1,2,3,4-tetra­hydro­isoquinoline-4-carboxyl­ate

In the title compound, C₁₃H₁₃NO₄, the fused-ring system is nearly planar, with an r.m.s. deviation of 0.0408 Å. In the crystal, mol­ecules are linked into centrosymmetric dimers by a pair of N—H...O hydrogen bonds. The ethyl group is disordered over two positions in a ratio of 0.758 (6):0.242 (6).

N-[1-(1H-Pyrrol-2-yl)ethyl­idene]aniline

There are two independent mol­ecules in the asymmetric unit of the title compound, C₁₂H₁₂N₂, in which the pyrrole and benzene rings form dihedral angles of 72.37 (7) and 82.34 (8)°. The imino N—C bond lengths in the two mol­ecules are equal [1.286 (2) Å] and indicate C=N character. In the crystal, each mol­ecule forms a dimer with an inversion-related mol­ecule through a pair of classical N—H...N hydrogen bonds.

2,4,6-Trimethyl-N-[1-(1H-pyrrol-2-yl)ethyl­idene]aniline

There are two independent mol­ecules in the asymmetric unit of the title compound, C₁₅H₁₈N₂, each of which features a syn disposition of the N atoms. In each mol­ecule, the pyrrole and benzene rings are essentially perpendicular, with dihedral angles of 78.90 (9) and 79.96 (9)°. In the crystal, the independent mol­ecules are connected by a pair of pyrrole–imino N—H...N hydrogen bonds, forming a two-mol­ecule aggregate.