1,2-Bis[(1,3-benzodioxol-5-yl)methyl­idene]hydrazine

The complete mol­ecule of the title compound, C₁₆H₁₂N₂O₄, is generated by the application of a centre of inversion. The (1,3-benzodioxol-5-yl)methyl­idene fused-ring system is approximately planar (r.m.s. deviation = 0.020 Å) and is essentially coplanar with the central hydrazine group [dihedral angle = 5.08 (9)°]. Weak π–π inter­molecular inter­actions are observed [centroid–centroid distance = 3.8553 (8) Å], providing some packing stability.

(1E,4E)-1-(3-Nitro­phen­yl)-5-phenyl­penta-1,4-dien-3-one

In the title compound, C₁₇H₁₃NO₃, the dihedral angle between the benzene rings is 31.21 (5)°. In the crystal, inversion dimers linked by pairs of C—H...O hydrogen bonds occur. A C—H...π inter­action is also indicated.

(2E)-2-[(3E)-4-Phenyl­but-3-en-2-yl­idene]hydrazinecarboxamide

In the title compound, C₁₁H₁₃N₃O, the phenyl ring is disordered over two sites, with occupancy factors in a 0.520 (17):0.480 (17) ratio. The dihedral angle between the ring planes of the major and minor components of the disordered ring is 12.9 (2)°. In the crystal, mol­ecules are linked by N—H...O hydrogen bonds, forming R₂²(8) ring motifs. C—H...O, C—H...N and C—H...π inter­actions also occur.

1,2-Bis(3-phen­oxy­benzyl­idene)hydrazine

Mol­ecules of the title compound, C₂₆H₂₀N₂O₂, reside on crystallographic centres of inversion located at the mid-point of the N—N bond. The benzyl­idene ring is essentially coplanar with the central hydrazine group, with an inter­planar angle of 4.5 (2)°, whereas the phenyl ring is oriented at 34.0 (3)° with respect to the mean plane of the central 1,2-dibenzyl­idenehydrazine group. In the crystal, C—H...π(arene)-ring inter­actions link mol­ecules about inversion centres.

3,3-Dimethyl-2-benzofuran-1(3H)-one

In the title compound, C₁₀H₁₀O₂, all the non-H atoms except the methyl C atoms lie on a crystallographic mirror plane. In the crystal, C—H...O hydrogen bonds link the mol­ecules into zigzag chains running parallel to [100]. Weak π–π stacking inter­actions between the benzene rings [centroid–centroid distance = 3.9817 (5) Å] link the chains in the [010] direction.

N-(4,6-Dimeth­oxy­pyrimidin-2-yl)-2-(3-methyl­phen­yl)acetamide

In the title compound, C₁₅H₁₇N₃O₃, the dihedral angle between the pyrimidine and benzene rings is 87.0 (7)°. In the crystal, mol­ecules are linked into inversion dimers with R₂²(8) graph-set motifs by a pair of N—H...O hydrogen bonds. Weak C—H...O hydrogen bonds and inter­molecular π–π inter­actions [centroid–centroid distance = 3.544 (1) Å] are also observed.