2-Isopropyl-5-methyl­cyclo­hexyl quinoline-2-carboxyl­ate

In the title compound, C₂₀H₂₅NO₂, the cyclo­hexyl ring adopts a slightly disordered chair conformation. The dihedral angle between the mean planes of the quinoline ring and the carboxyl­ate group is 22.2 (6)°. In the crystal, weak C—H...N inter­actions make chains along [010].

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

In the title compound, C₉H₁₀N₄OS, the dihedral angle between the benzene and 1H-1,2,4-triazole-5(4H)-thione rings is 67.51 (16)°. In the crystal, mol­ecules are liked via N—H...O hydrogen bonds, forming chains along the c-axis direction. The chains are linked via O—H...S hydrogen bonds, forming corrugated layers lying parallel to the bc plane. The layers are linked via N—H...N and N—H...S hydrogen bonds, forming a three-dimensional network.

4-[(E)-(4-Chloro­benzyl­idene)amino]-3-methyl-1H-1,2,4-triazole-5(4H)-thione

In the title compound, C₁₀H₉ClN₄S, the dihedral angle between the mean planes of the phenyl and 1H-1,2,4-triazole-5(4H)-thione rings is 25.3 (9)°. The latter ring is essentially planar, with maximum deviations of 0.010 and −0.010 Å for the ring N atom in the 4-position and ring C atom bearing the methyl group, respectively. An intra­molecular C—H...S contact occurs. In the crystal, pairs of weak N—H...S inter­actions link the mol­ecules into inversion dimers in the ac plane, forming R₂²(8) graph-set motifs. In addition, weak π–π inter­actions [centroid–centroid distances = 3.3463 (14) and 3.6127 (13)Å] are observed.

2,5-Di­methyl­phenyl quinoline-2-carboxy­l­ate

In the title compound, C₁₈H₁₅NO₂, the dihedral angle between the mean planes of the quinoline ring system and the phenyl ring is 78.8 (1)°. The mean plane of the carboxyl­ate group is twisted from the mean planes of the quinoline ring system and phenyl ring by 1.5 (9) and 77.6 (4)°, respectively. In the crystal, mol­ecules are linked by weak C—H...O inter­actions, generating C(8) chains along [001]. Weak π–π stacking inter­actions are also observed [centroid–centroid separation = 3.6238 (12) Å].

Enrofloxacinium oxalate

The title salt, 2C₁₉H₂₃FN₃O₃⁺·C₂O₄²⁻ {systematic name: bis-[4-(3-carb­oxy-1-cyclo­propyl-6-fluoro-4-oxo-1,4-di­hydro­quino­lin-7-yl)-1-ethyl­piperazin-1-ium] oxalate}, crystallizes with two independent monocations (A and B) and an oxalate dianion (C) in the asymmetric unit. The piperazinium ring in both the cations adopts a slightly disordered chair conformation. The dihedral angles between the mean planes of the cyclo­propyl ring and the 10-membered quinoline ring are 50.6 (5)° (A) and 62.2 (5)° (B). In each of the cations, a single O—H...O intra­molecular hydrogen bond is observed. In the crystal, the oxalate anions inter­act with the cations through N—H...O hydrogen bonds and weak C—H...O inter­actions, forming R₂²(8) graph-set ring motifs. Weak C—H...F inter­actions along with further C—H...O inter­actions are observed between the cations, forming zigzag chains along [001]. In addition, π–π stacking inter­actions are observed with centroid–centroid distances of 3.5089 (13), 3.5583 (13), 3.7900 (13) and 3.7991 (13) Å.

Flupentixol tartrate

In the title salt, C₂₃H₂₆F₃N₂OS⁺·C₄H₅O₆⁻ [systematic name: 1-(2-hy­droxy­eth­yl)-4-[3-(2-(tri­fluoro­meth­yl)thioxanthen-9-yl­idene)prop­yl]piperazin-1-ium 3-carb­oxy-2,3-di­hydroxy­pro­pion­ate], the monoprotonated piperazine ring in the cation adopts a chair conformation, while the thio­pyran ring of the thioxanthene group has a boat conformation. The dihedral angle between the mean planes of the two outer aromatic rings of the thioxanthene groups is 31.6 (2)°. In the crystal, the cations and anions are linked via O—H...O, N—H...O, O—H...N and C—H...O hydrogen bonds, forming chains propagating along [100]. In addition, R²₂(7), R²₂(11), R²₂(10) and R²₂(12) graph-set ring motifs involving the anions, and R²₂(9) graph-set ring motifs involving both the cations and anions are observed. The three F atoms of the tri­fluoro­methyl group are disordered over two sets of sites and the individual atoms were refined with occupancy ratios of 0.54 (6):0.46 (6), 0.72 (2):0.28 (2) and 0.67 (3):0.33 (3).

1-Piperonylpiperazinium picrate

In the cation of the title salt [systematic name: 4-(2H-1,3-benzodioxol-5-ylmeth­yl)piperazin-1-ium 2,4,6-tri­nitro­phen­o­late], C₁₂H₁₇N₂O₂⁺·C₆H₂N₃O₇⁻, the piperazine ring adopts a slightly disordered chair conformation. The piperonyl ring system and the piperazine ring are twisted with respect to each other with an N—C—C—C torsion angle of 40.7 (2)°. In the anion, the dihedral angles between the mean planes of the nitro substituents ortho to the phenolate O atom and the mean plane of the phenyl ring are 28.8 (9) and 32.2 (8)°. In contrast, the nitro group in the para position lies much closer to the aromatic ring plane, subtending a dihedral angle of 3.0 (1)°. In the crystal, the cations and anions inter­act through N—H...O hydrogen bonds and a weak C—H...O inter­action. Weak C—H...O inter­actions are also observed between the anions, forming R₂²(10) graph-set ring motifs. In addition, a weak centroid–centroid π–π stacking inter­action between the aromatic rings of the cation and the anion, with an inter­centroid distance of 3.7471 (9) Å, contributes to the crystal packing, resulting in a two-dimensional network along (10-1).

5-Amino-1H-pyrazol-2-ium hydrogen succinate

In the cation of the title salt, C₃H₆N₃⁺·C₄H₅O₄⁻, the protonated pyrazolium ring is planar (r.m.s. deviation = 0.012 Å). An intra­molecular C—H...O hydrogen bond occurs in the anion. In the crystal, N—H...O hydrogen bonds and a weak C—H...O inter­action between the cations and anions form two sets of R₂²(8) graph-set ring motifs. Inter­molecular O—H...O hydrogen bonds between these lead to a criss-cross pattern along the b axis. In addition to the classical hydrogen bonds, a weak C—H...π(pyrazolium) inter­action is observed and contributes to crystal packing. All of these inter­actions link the mol­ecules into a two-dimensional supra­molecular framework parallel to (10-1).

1-Piperonylpiperazinium 4-nitro­benzoate monohydrate

In the title hydrated salt [systematic name: 1-(1,3-benzodioxol-5-ylmeth­yl)piperazin-1-ium 4-nitro­benzoate monohydrate], C₁₂H₁₇N₂O₂⁺·C₇H₄NO₄⁻·H₂O, the piperazinium ring of the cation adopts a slightly distorted chair conformation. The piperonyl and piperazine rings are rotated with respect to each other with an N—C—C—C torsion angle of 45.6 (2)°. In the anion, the nitro group is almost coplanar with the adjacent benzene ring, forming a dihedral angle of only 3.9 (4)°. In the crystal, the cations, anions and water mol­ecules are linked through N—H...O and O—H...O hydrogen bonds into chains along the a axis. In addition, weaker inter­molecular C—H...O inter­actions are also observed within the chains. The anions form centrosymmetric couples through π-stacking inter­actions, with an inter­centroid distance of 3.681 (4) Å between the benzene rings.

1-Piperonylpiperazinium 4-chloro­benzoate

In the title salt {systematic name: 1-[(1,3-benzodioxol-5-yl)meth­yl]piperazin-1-ium 4-chloro­benzoate}, C₁₂H₁₇N₂O₂⁺·C₇H₄ClO₂⁻, the piperazine ring adopts a slightly disordered chair conformation. The dioxole ring is in a flattened envelope conformation with the methyl­ene C atom forming the flap. The relative orientation of the piperonyl ring system and the piperazine rings is reflected in the N—C—C[pdbond]C torsion angle of 132.3 (1)°. In the anion, the mean plane of the carboxyl­ate group is twisted from that of the benzene ring by 14.8 (9)°. In the crystal, the components are linked by N—H...O and weak C—H...O hydrogen bonds, forming chains along [010].

3-(1H-Imidazol-1-yl)propanaminium 2-carb­oxy-4,6-di­nitro­phenolate

In the title salt, C₆H₁₂N₃⁺·C₇H₃N₂O₇⁻, the imidazole ring is planar, with a maximum deviation of 0.0013 (14) Å for the N attached to the propanaminium group. In the anion, a single intra­molecular O—H...O hydrogen bond is observed. The mean planes of the nitro groups in the anion are twisted from the benzene ring mean plane making dihedral angles of 24.7 (9) and 3.9 (6)°. In the crystal, the ammonium H atoms form N—H...N and N—H...O hydrogen bonds, resulting in an infinite chain along [111]. In addition to the classical hydrogen bonds, weak C—H...O and π–π [centroid–centroid distance = 3.7124 (9) Å] inter­actions are also observed, which lead to the formation a three-dimensional supramolecular structure that links the chains into layers along the bc plane.

Methyl 1-benzyl-5-methyl-2,4-diphenyl-1H-pyrrole-3-carboxyl­ate

In the title compound, C₂₆H₂₃NO₂, the dihedral angles between the pyrrole ring and the two phenyl rings are 58.1 (6) and 71.5 (5)°. The mean planes of the 5-methyl­benzene ring and the carboxyl group are twisted by 89.5 (3) and 22.1 (9)°, respectively, from the pyrrole ring. In the crystal, weak C—H...O inter­actions lead to supra­molecular layers in the ab plane.

1-(3,4-Di­meth­oxy­phen­yl)-3-phenyl­prop-2-en-1-one

In the title compound, C₁₇H₁₆O₃, the dihedral angle between the mean planes of the benzene rings is 57.1 (1)°. The mean plane of the ketone group is twisted by 10.0 (5)° from that of the di­meth­oxy­phenyl ring. The two di­meth­oxy­phenyl groups are twisted slighly from the mean plane of the phenyl ring, with C—O—C—C torsion angles of 6.4 (2) and −7.9 (2)° [r.m.s. deviations = 0.15 (3) and 0.18 (3) Å for the two methoxy C atoms]. In the crystal, weak centroid–centroid π–π stacking inter­actions, with inter­centroid distances of 3.8939 (11) and 3.9430 (10) Å are observed.

5-(4-Fluoro­phen­yl)-2H-pyrazol-1-ium 2,2,2-tri­fluoro­acetate

The title salt, C₉H₈FN₂⁺·C₂F₃O₂⁻, crystallizes with two independent cations (A and B) and two independent anions (C and D) in the asymmetric unit. In the cations, the dihedral angles between the benzene and pyrazolium rings are 23.7 (3)° in cation A and 1.8 (8)° in cation B. In the crystal, each anion links to the two cations via N—H...O hydrogen bonds, forming a U-shaped unit with an R₄⁴(14) ring motif. These U-shaped units stack along the a axis and are linked via C—H...O and C—H...F hydrogen bonds, forming slabs lying parallel to (100). Within the slabs there are π–π inter­actions between the pyrazolium rings [inter-centroid distance = 3.6326 (15) Å] and between the benzene rings [inter-centroid distance = 3.7244 (16) Å]. In the anions, the F atoms of the tri­fluoro­methyl groups are disordered over two sets of sites, with refined occupancy ratios of 0.58 (3):0.42, 0.540 (14):0.46 (14), and 0.55 (2):0.45 (2) for anion C, and 0.73 (5):0.27 (5), 0.63 (5):0.37 (5), and 0.57 (8):0.43 (8) for anion D.

6-Chloro-2-chloro­methyl-4-phenyl­quinazoline 3-oxide

In the title compound, C₁₅H₁₀Cl₂N₂O, the dihedral angle between the mean planes of the phenyl ring and the 10-membered quinazoline ring is 63.3 (4)°. In the crystal, pairs of weak C—H...O inter­actions link the mol­ecules into centrosymmetric dimers, forming R₂²(10) graph-set ring motifs. In addition, weak π–π stacking inter­actions [minimum centroid–centroid separation = 3.6810 (8) Å] are observed, which contribute to the formation of a supramolecular assembly in the packing array.

(E)-2-{[(Furan-2-ylmeth­yl)imino]­meth­yl}-4-nitro­phenol

In the title compound, C₁₂H₁₀N₂O₄, the furan-2-ylmethyl group is disordered over two sets of sites, with refined occupancies of 0.858 (3) and 0.143 (3). In the major component of disorder, the dihedral angle between the furan and benzene rings is 63.1 (2)° and for the minor component this value is 67.9 (6)°. The planes of the nitro group and the attached benzene ring form a dihedral angle of 4.34 (17)°. In the crystal, inversion-related mol­ecules are linked by two pairs of weak C—H...O inter­actions, one involving the nitro group and the other involving the O—H group as an acceptor. As a result of these associations, ribbons are formed along [120]. A strong intra­molecular O—H...N hydrogen bond is observed.

{2-[(2-Hy­droxy­benzyl­idene)amino]-4,5,6,7-tetra­hydro-1-benzo­thio­phen-3-yl}(phen­yl)methanone

In the title compound, C₂₂H₁₉NO₂S, the cyclo­hexene ring adopts a slightly distorted half-chair conformation. The dihedral angles between the mean planes of the thio­phene ring and the phenyl and 2-hy­droxy­phenyl rings are 70.4 (5) and 12.1 (9)°, respectively. The phenyl and 2-hy­droxy­phenyl rings are twisted with respect to one another by 81.0 (6)°. A short intra­molecular O—H...N hydrogen bond is observed. In the crystal, weak C—H...O inter­actions link the mol­ecules into zigzag chains diagonally along [100] .

(4-Methyl­piperazin-1-yl)(2,3,4-tri­meth­oxy­benzyl­idene)amine

In the title compound, C₁₅H₂₃N₃O₃, the piperazine ring is in a slightly distorted chair conformation and is twisted from the mean plane of the benzene ring making a dihedral angle of 14.94 (6)°. The 4-meth­oxy substituent is almost co-planar with the benzene ring [C-C-O-C torsion angle = 5.4 (1)°], while the meth­oxy groups at positions 2 and 3 [C-C-O-C torsion angles of 122.6 (4) and -66.1 (4)°, respectively] are twisted away from the mean plane of the benzene ring in anti­clinical and synclinical conformations, respectively. No classical hydrogen bonds or any weak inter­molecular inter­actions are observed in the crystal structure.

{2-[(1H-Indol-3-yl­methyl­idene)amino]-4,5,6,7-tetra­hydro­benzo[b]thio­phen-3-yl}(phen­yl)methanone

The title compound, C₂₄H₂₀N₂OS, crystallizes with two independent mol­ecules (A and B) in the asymmetric unit, in each of which the cyclo­hexene rings adopt half-chair conformations. The mean plane of the indole ring is twisted from those of the phenyl and thio­phene rings by 69.0 (7) and 8.3 (5)°, respectively, in mol­ecule A and by 65.4 (9) and 6.7 (5)°, respectively, in mol­ecule B. The dihedral angles between the mean planes of the phenyl and thio­phene rings are 63.0 (4) and 58.8 (9)° in mol­ecules A and B, respectively. In the crystal, N—H...O hydrogen bonds lead to the formation of an infinite chain along [101]. In addition, π–π stacking inter­actions are observed involving the thio­phene and pyrrole rings of the two mol­ecules, with a shortest inter­centroid distance of 3.468 (2) Å.

[2-(Benzyl­idene­amino)-4,5,6,7-tetra­hydro­benzo[b]thio­phen-3-yl](phen­yl)methanone

In the title compound, C₂₂H₁₉NOS, the cyclo­hexene ring of the tetra­hydro­benzo­thio­phenyl ring system adopts a slightly distorted half-chair conformation and is twisted slightly [7.5 (8)° for the major disorder component] from the mean plane of the thio­phene ring. The dihedral angles between the mean planes of the thio­phene ring and the phenyl rings are 65.7 (3) and 8.3 (4)°. The phenyl rings are twisted with respect to each other by 73.8 (7)°. Disorder was modeled for four C atoms of the cyclo­hexene ring over two sets of sites with an occupancy ratio of 0.659 (2):0.341 (2). In the crystal, a single weak C—H...O inter­action links the mol­ecules into [001] chains.

(Z)-1-Di­phenyl­methyl-4-(3-phenyl­prop-2-en­yl)piperazine

In the title compound, C₂₆H₂₈N₂, the piperazine group adopts a chair conformation with the exocyclic N—C bonds in equatorial orientations. The dihedral angle between the geminal benzene rings is 80.46 (12)° and the C=C—C—N torsion angle is 145.9 (2)°. In the crystal, weak C—H...π inter­actions link the mol­ecules into [100] chains.

{2-[(2-Bromo-5-meth­oxy­benzyl­idene)amino]-4,5,6,7-tetra­hydro­benzo[b]thiophen-3-yl}(phen­yl)methanone

In the title compound, C₂₃H₂₀BrNO₂S, disorder was modeled for the outer two C atoms of the cyclo­hexene ring over two sets of sites with an occupancy ratio of 0.580 (11):0.420 (11). Both rings have a half-chair conformation. The dihedral angles between the mean plane of the thio­phene ring and the benzene and phenyl rings are 9.2 (2) and 66.1 (2)°, respectively. The benzene and phenyl rings are inclined to each other by 74.8 (8)°. In the crystal, mol­ecules are linked by pairs of C—H...O hydrogen bonds, forming inversion dimers.

(E)-2-{[4-(Di­methyl­amino)­benzyl­idene]amino}-5-nitro­phenol

The title Schiff base compound, C₁₅H₁₅N₃O₃, crystallizes with two mol­ecules (A and B) in the asymmetric unit. Each mol­ecule adopts an E conformation around the C= N imine bond. The two mol­ecules have minor differences in their conformations. In mol­ecule A, the dihedral angle between the nitro group and its benzene ring is 2.1 (2)° and that between the two benzene rings is 0.88 (7)°, while the corresponding angles for mol­ecule B are 5.7 (1) and 2.45 (6)°, respectively. In each mol­ecule, there is an intra­molecular O—H...N hydrogen bond. In the crystal, inversion-related mol­ecules are linked via O—H...O hydrogen bonds forming A–A and B–B dimers. These dimers are linked via C—H...O hydrogen bonds involving the nitro O atoms, forming A–A–A and B–B–B slabs that lie parallel to one another and to (010).

N-(1,5-Dimethyl-3-oxo-2-phenyl-2,3-di­hydro-1H-pyrazol-4-yl)-2-(4-nitro­phen­yl)acetamide

In the title compound, C₁₉H₁₈N₄O₄, the nitro­phenyl and phenyl rings are twisted by 67.0 (6) and 37.4 (4)°, respectively, with respect to the pyrazole ring plane [maximum deviation = 0.0042 (16) Å]. The dihedral angle between the mean planes of the phenyl rings is 59.3 (3)°. The amide group, with a C—N—C—C torsion angle of 177.54 (13)°, is twisted away from the plane of the pyrazole ring in an anti­periplanar conformation. In the crystal, N—H...O hydrogen bonds involving the carbonyl group on the pyrazole ring and the amide group, together with weak C—H...O inter­actions forming R₂²(10) graph-set motifs, link the mol­ecules into chains along [100]. Additional weak C—H...O inter­actions involving the nitro­phenyl rings further link the mol­ecules along [001], also forming R₂²(10) graph-set motifs, thereby generating (010) layers.

Flunarizinium isonicotinate

In the cation of the title salt {systematic name: 4-[bis­(4-fluoro­phen­yl)meth­yl]-1-[(2E)-3-phenyl­prop-2-en-1-yl]piperazin-1-ium pyridine-4-carboxyl­ate}, C₂₆H₂₇F₂N₂⁺·C₆H₄NO₂⁻, the piperazine ring is in a slightly distorted chair conformation. The dihedral angle between the mean planes of the fluoro-substituted benzene rings is 81.9 (1)° and these benzene rings form dihedral angles of 6.5 (1) and 87.8 (1)° with the phenyl ring. In the crystal, a single N—H...O hydrogen bond links the cation and the anion. In addition, weak C—H...O hydrogen bonds and π–π stacking inter­actions involving one of the fluoro-substituted benzene rings and the phenyl ring, with a centroid–centroid distance of 3.700 (7) Å, link mol­ecules along [100].

Pyrimethaminium 2-{[4-(tri­fluoro­meth­yl)phen­yl]sulfan­yl}benzoate dimethyl sulfoxide monosolvate

In the cation of the title solvated mol­ecular salt, C₁₂H₁₄ClN₄⁺·C₁₄H₈F₃O₂S⁻·C₂H₆OS [systematic name of the cation: 2,4-di­amino-5-(4-chloro­phen­yl)-6-ethyl­pyrimidin-1-ium], the dihedral angle between the planes of the pyrimidinium and 4-chloro­phenyl rings is 77.2 (5)°. In the anion, the planes of the benzene rings are twisted with respect to each other by 71.5 (5)°. Disorder was modelled for the dimethyl sulfoxide solvent mol­ecule over two set of sites in a 0.7487 (13):0.2513 (13) ratio. In the crystal, the cations are linked by inversion-generated pairs of N—H...N hydrogen bonds, with an R₂²(8) graph-set motif. The cation donates two N—H...O hydrogen bonds to the anion, also generating an R₂²(8) loop. These inter­actions, along with cation–solvent N—H...O hydrogen bonds, and cation–anion C—H...F, solvent–anion C—H...O and C—H...F inter­actions, result in a three-dimensional network.

1-[Bis(4-fluoro­phen­yl)meth­yl]-4-[(2Z)-3-phenyl­prop-2-en-1-yl]piperazine-1,4-diium dichloride hemihydrate

The asymmetric unit of the title monohydrated salt, 2C₂₆H₂₈F₂N₂²⁺·4Cl^−.H₂O, consists of a 1-[bis­(4-fluoro­phen­yl)meth­yl]-4-[(2Z)-3-phenyl­prop-2-en-1-yl]piperazine-1,4-diium cation with a diprotonated piperizine ring in close proximity to two chloride anions and a single water mol­ecule that lies on a twofold rotation axis. In the cation, the piperazine ring adopts a slightly distorted chair conformation. The dihedral angles between the phenyl ring and the 4-fluoro­phenyl rings are 89.3 (9) and 35.0 (5)°. The two fluoro­phenyl rings are inclined at 65.0 (5)° to one another. In the crystal, N—H...Cl hydrogen bonds and weak C—H...Cl inter­molecular inter­actions link the mol­ecules into chains along [010]. In addition, weak C—H...O inter­actions between the piperizine and prop-2-en-1-yl groups with the water mol­ecule, along with weak C—H...Cl inter­actions between the prop-2en-1-yl and methyl groups with the chloride ions, weak C—H...F inter­actions between the two fluoro­phenyl groups and weak O—H...Cl inter­actions between the water mol­ecule and chloride ions form a three-dimensional supra­molecular network.

4-(Furan-2-carbon­yl)piperazin-1-ium 3,5-di­nitro­benzoate

In the cation of the title salt, C₉H₁₃N₂O₂⁺·C₇H₃N₂O₆⁻, the piperazine ring adopts a slightly distorted chair conformation. Twofold rotational disorder is exhibited by the furan ring in a 0.430 (4):0.570 (4) ratio. In the crystal, N—H...O hydrogen bonds link the ions into chains along [010]. Additional weak C—H...O inter­actions are observed, leading to a supra­molecular layer parallel to (011).

4-(Pyrimidin-2-yl)piperazin-1-ium (E)-3-carb­oxy­prop-2-enoate

In the cation of the title salt, C₈H₁₃N₄⁺·C₄H₃O₄⁻, the piperazinium ring adopts a slightly distorteded chair conformation. In the crystal, a single strong O—H...O inter­molecular hydrogen bond links the anions, forming chains along the c-axis direction. The chains of anions are linked by the cations, via N—H...O hydrogen bonds, forming sheets parallel to (100). These layers are linked by weak C—H...O hydrogen bonds, forming a three-dimensional structure. In addition, there are weak π–π inter­actions [centroid–centroid distance = 3.820 (9) Å] present involving inversion-related pyrimidine rings.

2-(2-Methyl­phen­yl)-N-(1,3-thia­zol-2-yl)acetamide

In the title compound, C₁₂H₁₂N₂OS, the dihedral angle between the benzene and thia­zole rings is 83.5 (7)°. The acetamide group is almost coplanar with the thia­zole ring, being twisted from it by 4.2 (9)°. In the crystal, pairs of N—H...N hydrogen bonds link mol­ecules into inversion dimers, generating R₂²[8] loops; the dimers are stacked along [001].

4-Acetyl­piperazinium picrate

In the title salt, C₆H₁₃N₂O⁺·C₆H₂N₃O₇⁻ (systematic name: 4-acetyl­piperazin-1-ium 2,4,6-tri­nitro­phenolate), the piperazin-1-ium ring has a slightly distorted chair conformation. In the picrate anion, the mean planes of the two o-NO₂ and p-NO₂ groups are twisted with respect to the benzene ring by 15.0 (2), 68.9 (4) and 4.4 (3)°, respectively. In the crystal, N—H...O hydrogen bonds are observed, linking the ions into an infinite chain along [010]. In addition, weak cation–anion C—H...O inter­molecular inter­actions and a weak π–π stacking inter­action between the benzene rings of the anions, with an inter-centroid distance of 3.771 (8) Å, help to stabilize the crystal packing, giving an overall sheet structure lying parallel to (100). Disorder was modelled for one of the O atoms in one of the o-NO₂ groups over two sites with an occupancy ratio of 0.57 (6):0.43 (6).

N-Ethyl-2-[1-(2-hy­droxy­naphthalen-1-yl)ethyl­idene]hydrazinecarbo­thio­amide

In the title compound, C₁₅H₁₇N₃OS, the dihedral angle between the mean planes of the 2-hy­droxy­napthyl ring system and the hydrazinecarbo­thio­amide group is 73.7 (3)°. In the crystal, weak O—H...S and C—H...O inter­actions and π–π stacking inter­actions involving one of the hy­droxy­napthyl rings with a centroid–centroid distance of 3.6648 (14) Å are observed, forming infinite chains along [010]. In addition, N—H...S inter­actions occur.

4-[(E)-(4-Hy­droxy­benzyl­idene)amino]-3-methyl-1H-1,2,4-triazole-5(4H)-thione

The title compound, C₁₀H₁₀N₄OS, is nearly planar with the mean planes of the hy­droxy­benzyl and triazole rings inclined at an angle of only 3.2 (7)°. In the crystal, O—H...N hydrogen bonds between the hy­droxy group and the triazole ring in concert with weak N—H...S inter­molecular inter­actions between the triazole ring and thione group form chains along [-210] enclosing R₂²(8) graph-set motifs. A weak intra­molecular C—H...S inter­action and inter­molecular π–π inter­actions [centroid–centroid distance = 3.5990 (15) Å] are also observed.

N-Ethyl-2-[1-(2-hy­droxy-4-methyl­phen­yl)ethyl­idene]hydrazinecarbo­thio­amide

The title compound, C₁₂H₁₇N₃OS, crystallizes with two independent mol­ecules (A and B) in the asymmetric unit. The dihedral angle between the mean planes of the benzene ring and the hydrazinecarbo­thio­amide group are 6.9 (4) and 37.2 (5)° in mol­ecules A and B, respectively. An intra­molecular O—H...N hydrogen bond is observed in each mol­ecule. This serves to maintain an approximately planar conformation for mol­ecule A, but leaves a significant twist between these two groups in mol­ecule B. In the crystal, a weak N—H...S inter­action is observed, forming inversion dimers among the B mol­ecules and resulting in an R₂²(8) motif. These dimers are further inter­connected by weak N—H...O and C—H...O inter­molecular inter­actions, forming chains along [011].

3-(4-Fluoro­benzo­yl)-4-(4-fluoro­phen­yl)-4-hy­droxy-2,6-di­phenyl­cyclo­hexane-1,1-dicarbo­nitrile

In the title compound, C₃₃H₂₄F₂N₂O₂, the cyclo­hexane ring adopts a slightly distorted chair conformation. The dihedral angle between the planes of the phenyl rings is 71.80 (9)°, while the planes of the fluoro­phenyl and fluoro­benzoyl rings are inclined to one another by 31.04 (10)°. The dihedral angles between the planes of the phenyl ring adjacent to the 4-hydroxy group and those of the the fluoro­phenyl and fluoro­benzoyl rings are 51.64 (10) and 34.31 (10)°, respectively, while the corresponding angles for the phenyl ring adjacent to the 3-(4-fluorobenzoyl) group are 57.51 (9) and 85.02 (10)°, respectively. An intra­molecular O—H...O hydrogen bond generates an S(6) ring motif. In the crystal, mol­ecules are linked via pairs of O—H...N hydrogen bonds, forming inversion dimers. The dimers are linked via C—H...N and C—H...O hydrogen bonds, forming chains along the c-axis direction. C—H...F hydrogen bonds link the chains into sheets lying parallel to the bc plane.

{2-[(4-Nitro­benzyl­idene)amino]-4,5,6,7-tetrahydro-1-benzo­thio­phen-3-yl}(phen­yl)methanone

In the title compound, C₂₂H₁₈N₂O₃S, disorder is found in the benzoyl group (A and B), as well as for four C atoms of the cyclo­hexene ring. Two orientations were modeled in a 0.583 (5):0.417 (5) ratio. The cyclo­hexene ring is in a distorted chair conformation. The dihedral angles between the mean plane of the thio­phene ring and the 4-nitro­benzene and phenyl rings are 30.9 (8) and 64.8 (3) (A) and 62.4 (7)° (B). The mean planes of the 4-nitro­benzene and the phenyl rings are almost perpendicular to each other, with dihedral angles of 85.4 (1) (A) and 83.9 (8)° (B). An extensive array of weak C—H...O inter­actions consolidate mol­ecules into a three-dimensional architecture, forming chains along [001] and [010] and layers parallel to (011).

4-[(4-Acetyl­phen­yl)amino]-2-methyl­idene-4-oxo­butanoic acid

In the title compound, C₁₃H₁₃NO₄, the N—C(=O) bond length of 1.354 (2) Å is indicative of amide-type resonance. The dihedral angle between the mean planes of the benzene ring and oxo­amine group is 36.4 (3)°, while the mean plane of the 2-methyl­idene group is inclined by 84.2 (01)° from that of the oxo­amine group. In the crystal, classical O—H...O hydrogen bonds formed by the carb­oxy­lic acid groups and weak N—H...O weak inter­actions formed by the amide groups and supported by weak C—H...O inter­actions between the 2-methyl­idene, phenyl and acetyl groups with the carb­oxy­lic acid, oxo­amine and acetyl O atoms, together link the mol­ecules into dimeric chains along [010]. The O—H...O hydrogen bonds form R₂²(8) graph-set motifs.

1-{3-(4-Chloro­phen­yl)-5-[4-(propan-2-yl)phen­yl]-4,5-di­hydro-1H-pyrazol-1-yl}butan-1-one

In the title compound, C₂₂H₂₅ClN₂O, the pyrazole ring exhibits an envelope conformation with the methine C atom as the flap. The benzene rings are twisted by 3.3 (5) and 84.6 (5)° from the pyrazole mean plane, and are inclined to each other by 81.4 (4)°. In the crystal, pairs of weak C—H...O hydrogen bonds form centrosymmetric dimers with an R₂²(16) graph-set motif. C—H...π inter­actions link the dimers into columns propagating in [100].

1-{3-(4-Chloro­phen­yl)-5-[4-(propan-2-yl)phen­yl]-4,5-di­hydro-1H-pyrazol-1-yl}propan-1-one

In the title compound, C₂₁H₂₃ClN₂O, the dihedral angle between the benzene rings is 83.2 (6)°, while the mean plane of the pyrazole ring [r.m.s. deviation = 0.043 (1) Å] makes dihedral angles of 3.4 (3) and 86.2 (1)° with the benzene rings. In the crystal, a pair of weak C—H...O inter­actions between the benzene ring and the propan-1-one group link the mol­ecules into an inversion dimer with an R₂²(16) graph-set motif. In addition, a weak π–π stacking inter­action [centroid–centroid distance = 3.959 (4) Å] connects the dimers into a tape running along [201].

4-[(4-Bromo­phenyl)amino]-2-methyl­idene-4-oxo­butanoic acid

In the title compound, C₁₁H₁₀BrNO₃, two independent mol­ecules (A and B) crystallize in the asymmetric unit. The dihedral angles between the mean planes of the 4-bromo­phenyl ring and amide group are 24.8 (7) in mol­ecule A and 77.1 (6)° in mol­ecule B. The mean plane of the methyl­idene group is further inclined by 75.6 (4) in mol­ecule A and 72.5 (6)° in mol­ecule B from that of the amide group. In the crystal, N—H...O hydrogen bonds formed by amide groups and O—H...O hydrogen bonds formed by carb­oxy­lic acid groups are observed and supported additionally by weak C—H...O inter­actions between the methyl­idene and amide groups. Together, these link the mol­ecules into chains of dimers along [110] and form R₂²(8) graph-set motifs.

1-{3-(4-Chloro­phen­yl)-5-[4-(propan-2-yl)phen­yl]-4,5-di­hydro-1H-pyrazol-1-yl}ethanone

In the title compound, C₂₀H₂₁ClN₂O, the dihedral angles between the pyrazole ring (r.m.s. deviation = 0.049 Å) and the benzene and chloro­benzene rings are 84.65 (10) and 3.35 (10)°, respectively. In the crystal, inversion dimers linked by pairs of weak C—H...O inter­actions generate R₂²(16) loops. Weak π–π stacking inter­actions [centroid–centroid distance = 3.8490 (11) Å] are also observed.

(2E)-1-(4-Chloro­phen­yl)-3-[4-(propan-2-yl)phen­yl]prop-2-en-1-one

In the title compound, C₁₈H₁₇ClO, the dihedral angle between the benzene rings is 53.5 (1)°. The mean plane of the prop-2-en-1-one group is twisted by 24.5 (8) and 33.5 (3)° from the chloro- and propanyl-substituted rings, respectively.

Two tautomers in the same crystal: 3-(4-fluoro­phen­yl)-1H-pyrazole and 5-(4-fluoro­phen­yl)-1H-pyrazole

The title co-crystal, 3-(4-fluoro­phen­yl)-1H-pyrazole–5-(4-fluoro­phen­yl)-1H-pyrazole (1/1), C₉H₇FN₂, crystallizes with four independent mol­ecules (A, B, C and D) in the asymmetric unit exhibiting two tautomeric forms (A and D; B and C) due to N—H proton exchange between the two N atoms of the pyrazole ring. The dihedral angles between the mean planes of the pyrazole and benzene rings are 15.6 (1), 19.8 (9), 14.0 (1) and 10.7 (7)° in mol­ecules A, B, C and D, respectively. In the crystal, N—H...N hydrogen bonds link the four mol­ecules in the asymmetric unit into a ring with an R₄⁴(12) motif. Furthermore, weak C—H...F inter­actions link the mol­ecules into a three-dimensional network.

Crystal structure of N-(3-benzoyl-4,5,6,7-tetra­hydro-1-benzo­thio­phen-2-yl)benzamide

In the title compound, C₂₂H₁₉NO₂S, the cyclo­hexene ring adopts a half-chair conformation. The dihedral angles between the plane of the thio­phene ring and those of its amide- and carbonyl-bonded benzene rings are 7.1 (1) and 59.0 (2)°, respectively. An intra­molecular N—H...O hydrogen bond generates an S(6) ring. In the crystal, very weak aromatic π–π stacking inter­actions [centroid–centroid separation = 3.9009 (10) Å] are observed.

Crystal structure of N-[3-(2-chloro­benzo­yl)-5-ethyl­thio­phen-2-yl]-2-[(E)-(2-hy­droxy­benzyl­idene)amino]­acetamide

In the title compound, C₂₂H₁₉ClN₂O₃S, the dihedral angle between the mean planes of the thio­phene ring and the chloro­phenyl and hy­droxy­phenyl rings are 70.1 (1) and 40.2 (4)°, respectively. The benzene rings are twisted with respect to each other by 88.9 (3)°. The imine bond lies in an E conformation. Intra­molecular O—H...N and N—H...O hydrogen bonds each generate S(6) ring motifs. In the crystal, weak C—H...O inter­actions link the mol­ecules, forming chains along the c axis and zigzag chains along the b axis, generating sheets lying parallel to (100).

Crystal structure of 3-[4-(pyrimidin-2-yl)piperazin-1-ium-1-yl]butano­ate

The title compound, C₁₂H₁₈N₄O₂, crystallizes in the zwitterionic form with protonation at the N atom of the piperazine ring bearing the carboxylate group. The piperazine ring adopts a slightly distorted chair conformation. In the crystal, N—H...O hydrogen bonds are observed, forming chains along [010]. The packing is consolidated by C—H...O inter­actions, which generate a three-dimensional network.