4-Formyl-2-nitro­phenyl 3-nitro-2-methyl­benzoate

In the title formyl nitro aryl benzoate derivative, C₁₅H₁₀N₂O₇, the benzene rings form a dihedral angle of 4.96 (3)°. The mean plane of the central ester group, C—O—C–(=O)—C (r.m.s. deviation = 0.0484 Å), is twisted away from the formyl nitro aryl and benzoate rings by 46.61 (5) and 49.93 (5)°, respectively. In the crystal, the mol­ecules are packed forming C—H...O inter­actions in chains which propagate along [010]. Edge-fused R³₃(15) rings are generated along this direction.

3,4-Di­methyl­phenyl benzoate

In the title compound, C₁₅H₁₄O₂, the terminal rings form a dihedral angle of 52.39 (4)°. The mean plane of the central ester group [r.m.s. deviation = 0.0488 Å] is twisted away from the benzene and phenyl rings by 60.10 (4) and 8.67 (9)°, respectively. In the crystal, mol­ecules are linked by weak C—H...O hydrogen bonds, forming C(6) chains which run along [100].

4-Formyl-2-nitro­phenyl benzoate

In the title nitroaryl benzoate derivative, C₁₄H₉NO₅, the aromatic rings form a dihedral angle of 46.37 (8)°. The central ester moiety, —C—(C=O)—O—, is essentially planar (r.m.s. deviation for all non-H atoms = 0.0283 Å) and forms a dihedral angle of 54.06 (9)° with the 4-formyl-2-nitro­phenyl ring and 7.99 (19)° with the benzoate ring. In the crystal, mol­ecules are inter­twined by weak C—H...O inter­actions, forming helical chains along [100].

4-Bromo-N-(2-nitro­phen­yl)benzamide

The title nitro­phenyl benzamide, C₁₃H₉BrN₂O₃, with two mol­ecules in the asymmetric unit, has dihedral angles of 16.78 (15) and 18.87 (14)° between the benzene rings. An intra­molecular N—H...O hydrogen bond is observed in each mol­ecule. In the crystal, the molecules are linked by weak C—H...O inter­actions; halogen–halogen inter­actions are also observed [Br...Br = 3.4976 (7) Å]. These inter­actions form R²₂(10), R²₂(15) and R⁶₆(32) edge-fused rings along [010].

N-(2-Nitro­phen­yl)thio­phene-2-carbox­amide

The title compound, C₁₁H₈N₂O₃S, shows two mol­ecules per asymmetric unit, with the dihedral angles between the benzene and thio­phene rings of 13.53 (6) and 8.50 (5)° being a notable difference between them. An intra­molecular N—H...O hydrogen-bond in each mol­ecule generates an S(6) ring motif. The crystal packing shows no classical hydrogen bonds with the mol­ecules being packed to form weak C—H...O and C—H...S inter­actions leading to R₂²(9) and R₄⁴(25) rings which are edge-shared, giving layers parallel to (010).