A second monoclinic polymorph of 4-[(E)-(4-benzyl­oxybenzyl­idene)amino]-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one

In the title compound, C₂₅H₂₃N₃O₂, the central benzene ring makes dihedral angles of 77.14 (8) and 87.7 (2)° with the terminal benzene rings and an angle of 1.9 (1)° with the pyrazolone ring. The benzene ring and the N atom of the pyrazole ring bearing the phenyl substituent are disordered over two sets of sites with an occupancy ratio of 0.71 (2):0.29 (2). The N atoms of the pyrazole ring have a pyramidal environment, the sums of the valence angles around them being 354.6 (3) and 352.0 (6)/349.5 (15)°. In the crystal, mol­ecules are packed into layers parallel to the ac plane. The other monoclinic polymorphic form was reported recently [Dutkiewicz et al. (2012). Acta Cryst. E68, o1324].

3-Chloro-4-fluoro­anilinium picrate

In the title picrate salt of a dihalogenated aniline derivative, C₆H₆ClF⁺·C₆H₂N₃O₇⁻, the intra­cyclic C—C—C angles in the picrate anion cover a broad range [111.95 (12)–125.38 (13)°], while those in the aromatic cation span a much narrower range [118.25 (14)–122.33 (13)°]. In the crystal, classical N—H...O hydrogen bonds, as well as C—H...O contacts, connect the ions into layers parallel to (001).

(Z)-4-[2-(2,4-Dimethyl­phen­yl)hydrazinyl­idene]-3-methyl­pyrazol-5(1H)-one

The mol­ecule of the title compound, C₁₂H₁₄N₄O, is roughly planar, with a dihedral angle of 8.0 (8)° between the benzene and pyrazole rings, and an intra­molecular N—H...O hydrogen bond forms an S(6) ring motif. In the crystal, mol­ecules are linked into an inversion dimer by a pair of N—H...O hydrogen bonds, which form an R₂²(8) ring motif.

3-Methyl-4-{(E)-[4-(methyl­sulfan­yl)benzyl­idene]amino}-1H-1,2,4-triazole-5(4H)-thione

In the title mol­ecule, C₁₁H₁₂N₄S₂, the dihedral angle between the triazole and benzene rings is 21.31 (5)°. A weak intra­molecular C—H...S hydrogen bond generates an S(6) ring motif. In the crystal, pairs of N—H...S hydrogen bonds form inversion dimers. In addition, π–π inter­actions are observed between the benzene rings, with a centroid–centroid separation of 3.7599 (11) Å.

4-Amino-3-(3-meth­oxy­benz­yl)-1H-1,2,4-triazole-5(4H)-thione

In the title mol­ecule, C₁₀H₁₂N₄SO, the triazole ring forms a dihedral angle of 73.0 (5)° with the benzene ring. The meth­oxy group is approximtely coplanar with the benzene ring with a C[pdbond]C—O—C_meth­yl torsion angle of 4.7 (3)°. In the crystal, N—H...S hydrogen bonds connect pairs of inversion-related mol­ecules, which are in turn connected by N—H...N hydrogen bonds into chains of rings along [010]. Weak C—H...O hydrogen bonds connect these chains into a two-dimensional network parallel to (-102).

4-Hy­droxy-N-methyl­benzamide

Three independent mol­ecules comprise the asymmetric unit of the title compound, C₈H₉NO₂, in which the dihedral angles between the amide group and the benzene ring are 3.0 (2), 4.0 (3) and 3.3 (9)°. In the crystal, O—H...O hydrogen bonds and weak C—H...N inter­actions are observed, forming infinite chains along [101].

(2E)-1-(4-Chloro­phen­yl)-3-(4-nitro­phen­yl)prop-2-en-1-one

In the title compound, C₁₅H₁₀ClNO₃, a substituted chalcone, the dihedral angle between the benzene rings is 5.1 (7)°. The nitro group makes a dihedral angle of 12.5 (3)° with the benzene ring to which it is attached. In the crystal, weak C—H...O inter­actions link the mol­ecules into a one-dimensional array along [010]. The crystal studied was an inversion twin, with a refined ratio for the twin components of 0.6060 (9):0.3939 (1).

2-(4-Bromo­phen­yl)-N-(pyrazin-2-yl)acetamide

In the title compound, C₁₂H₁₀BrN₃O, the dihedral angle between the mean planes of the 4-bromo­phenyl and pyrazin-2-yl rings is 54.6 (3)°. An intra­molecular C—H...O hydrogen bond generates an S(6) graph-set motif. In the crystal, weak N—H...N hydrogen bonds link the mol­ecules into chains along [100]. The chains are linked via C—H...N and C—H...O hydrogen bonds, forming two-dimensional networks lying parallel to the ab plane.

2-(4-Bromo­phen­yl)-N-(3,4-di­fluoro­phen­yl)acetamide

In the title compound, C₁₄H₁₀BrF₂NO, the dihedral angle between the mean planes of the 4-bromo­phenyl and 3,4-di­fluoro­phenyl rings is 66.4 (1)°. These two planes are twisted by 40.0 (5) and 86.3 (2)°, respectively, from that of the acetamide group. In the crystal, N—H...O hydrogen bonds and weak C—H...O and C—H...F inter­actions form infinite chains along [100].

2-(4-Chloro­phen­yl)-N-(3,4-di­fluoro­phen­yl)acetamide

In the title compound, C₁₄H₁₀ClF₂NO, the dihedral angle between the mean planes of the 4-chloro­phenyl and 3,4-di­fluoro­phenyl rings is 65.2 (1)°. These two planes are twisted by 83.5 (5) and 38.9 (9)°, respectively, from that of the acetamide group. In the crystal, N—H...O hydrogen bonds form infinite chains along [100]. Weak C—H...O and C—H...F inter­actions are also observed and stack mol­ecules along the b axis.