2-{(E)-[(2Z)-(3-Chloro-1-methyl-2,2-di­oxo-3,4-dihydro-1H-2,1-benzo­thia­zin-4-yl­idene)hydrazinyl­idene]meth­yl}phenol

In the title compound, C₁₆H₁₄ClN₃O₃S, the thia­zine ring adopts a sofa (half-chair) conformation, with an r.m.s. deviation from the mean plane of 0.23 Å. The S atom and S-bonded C atom exhibit the maximum deviations from the thia­zine mean plane [−0.3976 (12) and 0.3179 (14) Å, respectively]. The conformations around the double bonds in the R₂C=N—N=CHR unit are Z and E. An intra­molecular O—H...N hydrogen bond with the hy­droxy group as donor generates an S(6) ring motif. In the crystal, pairs of weak C—H...O inter­actions connect the mol­ecules, forming inversion dimers.

(2E)-2-(4-Bromo­benzyl­idene)-2,3-di­hydro-1H-inden-1-one

The title indan-1-one derivative, C₁₆H₁₁BrO, is planar, the r.m.s. deviation for all 18 non-H atoms being 0.071 Å. The configuration about the C=C bond [1.337 (5) Å] is E. In the crystal, supra­molecular layers in the ab plane are formed by C—H...O inter­actions, involving the bifurcated carbonyl O atom, as well as C—H...π inter­actions. The studied crystal was an inversion twin.

4-{(4Z)-4-[(2Z)-3-(4-Fluoro­anilino)-1-hy­droxy­but-2-en-1-yl­idene]-3-methyl-5-oxo-4,5-dihydro-1H-pyrazol-1-yl}­benzene­sulfonamide

In the title compound, C₂₀H₁₉FN₄O₄S, the pyrazole and benzene­sulfonamide rings are coplanar [dihedral angle = 5.02 (15)°] but this planarity does not extend over the entire mol­ecule, the dihedral angle between the terminal six-membered rings being 33.24 (14)°. Intra­molecular hy­droxy–hy­droxy O—H...O and amine–hy­droxy N—H...O hydrogen bonds, as a well as a tight C—H...O(carbon­yl) inter­action, lead to a sequence of three fused S(6) rings. Supra­molecular chains along the a axis feature in the crystal packing; these chains are stabilized by amine–sulfonamide N—H...O and amine–pyrazole N—H...N hydrogen bonds.

(2Z)-3-(4-Fluoro­anilino)-1-(5-hy­droxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)but-2-en-1-one

The central carbonyl group in the title compound, C₂₀H₁₈FN₃O₂, forms amine–hy­droxy N—H...O and hy­droxy–hy­droxy O—H...O hydrogen bonds, leading to two S(6) rings. The N-bound phenyl ring is coplanar with the five-membered ring to which it is attached [dihedral angle = 6.27 (10)°], but an overall twist in the mol­ecule is evident, the dihedral angle between the terminal phenyl and benzene rings being 27.30 (10)°. Mol­ecules aggregate into a three-dimensional architecture via C—H...F, C—H...O and C—H...π inter­actions.

(2Z)-1-(5-Hy­droxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)-3-(4-methyl­anilino)­but-2-en-1-one

A twist is evident in the title compound, C₂₁H₂₁N₃O₂, the dihedral angle between the terminal six-membered rings being 29.46 (10)°; the linked five- and six-membered rings are coplanar [1.30 (11)°]. The carbonyl O atom accepts intra­molecular hydrogen bonds from the adjacent hy­droxy and amine groups. The three-dimensional crystal packing is achieved through C—H...π inter­actions.

(2Z)-3-(3-Bromo­anilino)-1-(5-hy­droxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)but-2-en-1-one

In the title compound, C₂₀H₁₈BrN₃O₂, the central carbonyl group forms amine-N—H...O and hy­droxy-O—H...O hydrogen bonds, which lead to two fused S(6) rings. The N-bound phenyl ring is coplanar with the five-membered ring to which it is attached [dihedral angle = 5.22 (18)°], but the dihedral angle [33.87 (17)°] between the terminal phenyl and bromo­benzene rings indicates an overall twist in the mol­ecule. In the crystal packing, mol­ecules assemble into dimeric aggregates via C—H...π inter­actions.

(2E)-2-[(2E)-3-Phenyl­prop-2-en-1-yl­idene]-2,3-dihydro-1H-inden-1-one

The title indan-1-one derivative, C₁₈H₁₄O, is planar with an r.m.s. deviation for all 19 non-H atoms of 0.098 Å. The conformation about each of the C=C bonds [1.343 (3) and 1.349 (3) Å] is E. Supra­molecular layers in the bc plane, mediated by C—H...O and π–π [ring centroid–centroid distance = 3.5282 (15) Å] inter­actions, feature in the crystal packing.

(2E)-2-(4-Meth­oxy­benzyl­idene)-2,3-di­hydro-1H-inden-1-one

In the title compound, C₁₇H₁₄O₂, the indan-1-one system is almost planar (r.m.s. deviation = 0.007 Å) and the benzene ring is twisted out of its plane by 8.15 (6)°. The conformation about the C=C double bond [1.348 (2) Å] is E. Helical supra­molecular chains along [010] feature in the crystal packing; these are sustained by C—H...O hydrogen bonds and π–π inter­actions between translationally related indan-1-one systems [centroid–centroid distance = 3.7970 (10) Å].

(2E)-2-[(2H-1,3-Benzodioxol-5-yl)methyl­idene]-2,3-dihydro-1H-inden-1-one

In the title compound, C₁₇H₁₂O₃, each of the five-membered rings in the inden-1-one and 1,3-benzodioxole residues is almost planar (r.m.s. deviations = 0.041 and 0.033 Å, respectively). A small twist about the single bond linking the two residues is evident [the C—C—C—C torsion angle = 8.7 (4)°]. Supra­molecular zigzag layers propagating in the ac plane are formed in the crystal via C—H...O inter­actions. The layers are linked via π–π inter­actions between the five- and six-membered rings of 1,3-benzodioxole residues [centroid–centroid distance = 3.4977 (14) Å].

N,N′-Bis[(E)-1-(thio­phen-3-yl)ethyl­idene]ethane-1,2-diamine

The complete mol­ecule of the title compound, C₁₄H₁₆N₂S₂, is generated by a crystallographic inversion centre. The thio­phene residue is close to being coplanar with the imine group [C—C—C—N torsion angle = 6.5 (2)°], and the conformation about the imine C=N bond [1.281 (2) Å] is E. In the crystal, the three-dimensional architecture is consolidated by C—H...N, C—H...π and S...S [3.3932 (7) Å] inter­actions.

3-Amino-1-(thio­phen-2-yl)-9,10-dihydro­phenanthrene-2,4-dicarbonitrile

In the title compound, C₂₀H₁₃N₃S, the partially saturated ring adopts a twisted half-boat conformation with the methyl­ene C atom closest to the amino­benzene ring lying 0.690 (6) Å out of the plane defined by the five remaining atoms. The dihydro­phenanthrene residue has a folded conformation [dihedral angle between the outer benzene rings = 26.27 (18)°]. The thio­phen-2-yl ring forms a dihedral angle of 63.76 (19)° with the benzene ring to which it is attached. In the crystal, inversion dimers linked by pairs of N—H...N hydrogen bonds generate R₂²(12) loops. The dimers are linked into layers in the bc plane by weak C—H...π inter­actions. The thio­phen-2-yl ring is disordered over two essentially coplanar but opposite orientations in a 0.918 (4):0.082 (4) ratio.

4a-Methyl-2,3,4,4a-tetra­hydro-1H-carbazole-6-sulfonamide

In the title mol­ecule, C₁₃H₁₆N₂O₂S, the nine non-H atoms comprising the indole residue are approximately coplanar (r.m.s. deviation = 0.031 Å). The partially saturated ring adopts a chair conformation. One amine H forms an inter­molecular N—H...O hydrogen bond to a sulfonamide O atom, while the other amine H form is connected to the indole N atom of an adjacent mol­ecule via an N—H...N hydrogen bond, resulting in a three-dimensional architecture.

3,5-Dimethyl-1-phenyl-1H-pyrazole-4-carbaldehyde

In the title mol­ecule, C₁₂H₁₂N₂O, the five- and six-membered rings form a dihedral angle of 68.41 (16)°. The aldehyde group is nearly coplanar with the pyrazole ring [C—C—C—O torsion angle = −0.4 (5)°]. The three-dimensional architecture is sustained by weak C—H...O and C—H...π inter­actions.

(2E)-2-(Furan-2-yl­methyl­idene)-2,3-dihydro-1H-inden-1-one

In the title compound, C₁₄H₁₀O₂, the five-membered ring of the inden-1-one residue is almost planar (r.m.s. deviation = 0.035 Å). A twist about the single bond linking the two residues is evident [C—C—C—C torsion angle = −13.2 (5)°]. The three-dimensional architecture is stabilized by C—H...O (involving the trifurcated carbonyl O atom), C—H...π and π–π inter­actions [between the five- and six-membered rings of inden-1-one residues; ring centroid–centroid distance = 3.7983 (17) Å]. The sample studied was a non-merohedral twin; the minor component refined to approximately 36%.

1-Phenyl-1H-pyrazole-4-carbaldehyde

In the title mol­ecule, C₁₀H₈N₂O, the five- and six-membered rings form a dihedral angle of 10.14 (9)°. The aldehyde group is almost coplanar with the pyrazole ring to which it is connected [O—C—C—C torsion angle = −179.35 (17)°]. In the crystal, inversion dimers are linked by four C—H...O inter­actions as the carbonyl O atom accepts two such bonds. The dimeric aggregates are linked into supra­molecular layers in the ac plane by C—H...π and π–π [ring centroid(pyrrole)...ring centroid(phen­yl) = 3.8058 (10) Å] inter­actions.

3-Amino-1-(3,4-dimeth­oxy­phen­yl)-9,10-dihydro­phenanthrene-2,4-dicarbonitrile

In the title compound, C₂₄H₁₉N₃O₂, the partially saturated ring adopts a distorted half-chair conformation with the methyl­ene-C atom closest to the amino­benzene ring lying 0.664 (3) Å out of the plane defined by the five remaining atoms (r.m.s. deviation = 0.1429 Å. The dihedral angle [32.01 (10)°] between the benzene rings on either side of this ring indicates a significant fold in this part of the mol­ecule. The dimeth­oxy-substituted benzene ring is almost orthogonal to the benzene ring to which it is attached [dihedral angle = 72.03 (9)°]. The mol­ecule has been observed previously as the major component of a 1:19 co-crystal with 2-amino-4-(3,4-dimeth­oxy­phen­yl)-5,6-dihydro­benzo[ha]quinoline-3-carbonitrile [Asiri et al. (2011). Acta Cryst. E67, o2873–o2873]. Supra­molecular chains with base vector [201] are formed in the crystal structure via N—H...O hydrogen bonds between the amino H atoms of one mol­ecule inter­acting with the meth­oxy O atoms of a neighbouring mol­ecule. The chains are linked into a three-dimensional architecture by C—H...π inter­actions.

3,6-Dimethyl-1-phenyl-1H,4H-pyrano[2,3-c]pyrazol-4-one

The title compound, C₁₄H₁₂N₂O₂, is almost planar with an r.m.s. deviation for all non-H atoms of 0.038 Å. The observed planarity is rationalized in terms of a close intra­molecular C—H...O inter­action. Supra­molecular layers, two mol­ecules thick and with a step topology, are formed in the crystal packing via C—H...O contacts involving the carbonyl O atom, which accepts two such bonds, and π–π inter­actions between the components of the fused ring system and the phenyl ring of inversion-related mol­ecules [centroid–centroid distances = 3.6819 (13) and 3.6759 (12) Å].

2-(4-Sulfamoylphen­yl)hydrazin-1-ium chloride

The hydrazinium residue in the cation of the title salt, C₆H₁₀N₃O₂S⁺·Cl⁻, is twisted out of the plane of the benzene ring to which it is attached [N—N—C—C torsion angle = 25.9 (2)°] and the amino group is almost perpendicular to the benzene ring [N—S—C—C torsion angle = 88.71 (16)°]. In the crystal, the cations are linked by N—H...O hydrogen bonds and π–π inter­actions [ring centroid distance = 3.7280 (11) Å], forming layers in the bc plane that are connected by N—H...Cl hydrogen bonds.

(4Z)-4-Benzyl­idene-2-phenyl-1,3-oxazol-5(4H)-one

In the title compound, C₁₇H₁₃NO₂, the benzene ring is twisted slightly out of the plane of the oxazole ring to which it is attached [dihedral angle = 7.98 (8)°]. Similarly, there is a twist [dihedral angle = 5.50 (8)°] between the oxazole and phenyl rings that are linked via the C=C bond [1.348 (2) Å]; the conformation about the latter is Z. In the crystal, the presence of C—H...O, C—H...π and π–π inter­actions [centroid–centroid distance = 3.5259 (9) Å] link the mol­ecules into a three-dimensional architecture.

N-(4-Sulfamoylphen­yl)acetamide

In the title compound, C₈H₁₀N₂O₃S, the dihedral angle between the acetamide group and the benzene ring is 15.59 (12)° and the amino group is close to being perpendicular to the benzene ring [N—S—C_ar—C_ar (ar = aromatic) torsion angle = 109.4 (2)°]. In the crystal, mol­ecules are linked into supra­molecular tubes parallel to [001] by amine–amide N—H...O inter­actions and these are connected into the three-dimensional architecture by amide–sulfonamide N—H...O hydrogen bonds. The crystal studied was a racemic twin.

4-[(1,3-Thia­zol-2-yl)sulfamo­yl]phenyl 2,2,2-trifluoro­acetate

In the title compound, C₁₁H₇F₃N₂O₄S₂, the 1,3-thia­zol-2-amine residue is almost perpendicular to the central benzene ring [dihedral angle = 84.3 (2)°]. There is a small twist between the benzene ring and the ester group [C—O—C—C torsion angle = 9.8 (6)°]. Thus, the mol­ecule has an L-shape. Inversion-related dimers are connected in the crystal packing by pairs of N—H...N hydrogen bonds formed between the amine H and thia­zole N atom via eight-membered {...HNCN}₂ synthons.

A second monoclinic polymorph for 3-amino-1-(4-meth­oxy­phen­yl)-9,10-dihydro­phenanthrene-2,4-dicarbonitrile

The title compound, C₂₃H₁₇N₃O, has been previously described in a monoclinic P2₁/c polymorph with Z = 4 [Asiri, Al-Youbi, Faidallah, Ng & Tiekink (2011). Acta Cryst. E67, o2449]. In the new monoclinic P2₁/n form, with Z = 8, there are two independent mol­ecules, A and B, in the asymmetric unit. In both mol­ecules, the cyclo­hexa-1,3-diene ring has a screw-boat conformation, whereas it is a distorted half-chair in the original polymorph. There is a fold in each mol­ecule, as indicated by the dihedral angle between the benzene rings of the 1,2-dihydro­naphthalene and aniline residues of 33.19 (10)° (mol­ecule A) and 30.6 (10)° (mol­ecule B). The meth­oxy­benzene ring is twisted out of the plane of the aniline residue to which it is connected [dihedral angles = 49.22 (10) and 73.27 (10)°, in A and B respectively]. In the crystal, the two independent mol­ecules self-associate via N—H...N hydrogen bonds, generating a 12-membered {...HNC₃N}₂ synthon. These are connected into a supra­molecular tape in the (-101) plane by N—H...O(meth­oxy) inter­actions. In the P2₁/c polymorph, supra­molecular layers are formed by N—H...N and N—H...O inter­actions.

4-[5-(Furan-2-yl)-3-trifluoro­methyl-1H-pyrazol-1-yl]benzene­sulfonamide

In the title compound, C₁₄H₁₀F₃N₃O₃S, there are significant twists in the mol­ecule, as seen in the values of the dihedral angles between the pyrazole ring and each of the furan [31.1 (2)°] and benzene rings [55.58 (10)°]. The amino N atom occupies a position almost normal to the benzene ring [N—S—C_ar—C_ar (ar = aromatic) torsion angle = 83.70 (19)°]. One amino H atom forms a hydrogen bond to the tricoordinate pyrazole N atom and the other inter­acts with a sulfonamide O atom, forming a supra­molecular chain along [010]. The chains are consolidated into a supra­molecular layers via C—H...O inter­actions involving the second sulfonamide O atom; layers stack along [10-1]. The furan ring was found to be disordered over two diagonally opposite orientations of equal occupancy.

2-[(1-Methyl-1H-pyrrol-2-yl)methyl­idene]propane­dinitrile

In the title compound, C₉H₇N₃, the N-bound methyl group and vinyl H atom are syn. The 12 non-H atoms comprising the mol­ecule are essentially coplanar (r.m.s. deviation = 0.071 Å). Supra­molecular tapes feature in the crystal packing, orientated perpendicular to [10-1], and are formed by C—H...N inter­actions involving each cyano N atom. The tapes are connected into layers via π–π inter­actions occurring between translationally related pyrrole rings [ring centroid–centroid distance = 3.8754 (10) Å]; the layers stack along the b axis.

N-Acetyl-N-[2,4-dicyano-1-(4-meth­oxy­phen­yl)-9,10-dihydro­phenanthren-3-yl]acetamide

In the title compound, C₂₇H₂₁N₃O₃, the cyclo­hexa-1,3-diene ring has a screw-boat conformation, and the fused ring system is folded, the dihedral angle between the outer benzene rings being 27.61 (6)°. The N-acetyl­acetamide residue (r.m.s. deviation = 0.0935 Å) has an anti conformation and is essentially perpendicular to the benzene ring to which it is connected [dihedral angle = 89.14 (6)°]; the meth­oxy­benzene group is also twisted out of this ring [dihedral angle = 59.47 (7)°]. The three-dimensional architecture is consolidated by C—H...O and C—H...π inter­actions.

4-{2-[(E)-Cyclo­pentyl­idene]hydrazin-1-yl}benzene­sulfonamide

The title mol­ecule, C₁₁H₁₅N₃O₂S, features a five-membered ring which is twisted about the middle CH₂-CH₂ bond. The benzene ring is inclined with respect to the imine residue [C-N-N-C torsion angle = 165.4 (2)°]. Supra­molecular layers in the bc plane are formed by hydrogen bonds between the amine H atoms and sulfonamide O and imine N atoms, as well as by a weak hydrazine H-atom inter­molecular inter­action with the second sulfonamide O atom.

1-[(Z)-1-Ferrocenyl­ethyl­idene]thio­carbonohydrazide

In the title compound, [Fe(C₅H₅)(C₈H₁₁N₄S)], the cyclo­penta­dienyl (Cp) rings of the ferrocene unit are close to being eclipsed. They are inclined to one another at an angle of 1.95 (2)° and lie 3.309 (2)Å away from each other. The ethyl­idene­thio­carbonohydrazide fragment is planar, with an r.m.s. deviation of 0.0347 (2) Å from the mean plane of its eight non-H atoms, and makes dihedral angles of 21.78 (1) and 19.97 (1)° with respect to the two Cp rings. The mol­ecule adopts a trans geometry about the C=N double bond. In the crystal, N—H...(N/S) and C—H...S inter­actions stack the mol­ecules in an inverse fashion along the b axis.

cis-Dichloridobis(N,N,N′,N′-tetra­methyl­ethane-1,2-diamine)­platinum(II)

In the title complex, [PtCl₂(C₆H₁₆N₂)], the Pt^II atom adopts a distorted cis-PtN₂Cl₂ square-planar coordination geometry. The five-membered chelate ring adopts a twisted conformation. In the crystal, weak C—H...Cl hydrogen bonds link the mol­ecules into (001) sheets.

Methyl 2-butyl-4-hy­droxy-1,1-dioxo-2H-1,2-benzothia­zine-3-carboxyl­ate

In the title compound, C₁₄H₁₇NO₅S, the thia­zine ring adopts a half-chair conformation. The mol­ecule exhibits an intra­molecular O—H...O hydrogen bond, which forms a six-membered S(6) ring motif. The planes of the benzene and thia­zine rings are inclined at a dihedral angle of 15.30 (12)°.

3-[(E)-Benzyl­idene]indolin-2-one

In the title indolin-2-one derivative, C₁₅H₁₁NO, the phenyl ring and the oxoindoline fused-ring system (r.m.s. deviation = 0.011 Å) are aligned at 48.52 (6)°. In the crystal, inversion-related mol­ecules form an N—H...O hydrogen-bonded dimer via an eight-membered {...HNCO}₂ synthon. The dimeric aggregates are linked into a three-dimensional architecture via C—H...O and π–π inter­actions between the five- and six-membered rings of the fused ring system, with an inter-centroid distance of 3.4538 (8) Å.

2-[(E)-4-Meth­oxy­benzyl­idene]-1,2,3,4-tetra­hydro­naphthalen-1-one

Two independent mol­ecules (A and B) comprise the asymmetric unit of the title compound, C₁₈H₁₆O₂. Mol­ecule B is virtually superimposable upon A. Minor differences are noted in the dihedral angles between the terminal benzene rings of 56.03 (10) and 54.62 (10)°, and in the orientations of meth­oxy groups with respect to the benzene rings to which they are attached [C—O—C—C torsion angles = 169.11 (19) and −172.37 (18)°]. The cyclo­hexene ring of each fused ring system has a screw-boat conformation. In the crystal, C—H...π inter­actions assemble mol­ecules into a supra­molecular array in the ab plane.

5-Chloro-3,6-dimethyl-1-phenyl-1H,4H-pyrano[2,3-c]pyrazol-4-one

In the title compound, C₁₄H₁₁ClN₂O₂, two independent mol­ecules (A and B) comprise the asymmetric unit with the main difference between them being the relative orientation of the pendent phenyl ring with respect to the fused-ring system [dihedral angles = 8.32 (8)° (A) and 28.32 (8)° (B)]. In the crystal, the A mol­ecules are connected into a linear supra­molecular chain along the a axis via C—H...O inter­actions and linked to this via C—H...Cl inter­actions are the B mol­ecules. The chains are connected into layers in the ab plane by π–π inter­actions between pyrazole (A) and pyran (B) rings, and between pyrazole (B) and pyran (A) rings [centroid–centroid distances = 3.5442 (11) and 3.4022 (10) Å, respectively].

4-(3-Phenyl-3,3a,4,5-tetra­hydro-2H-benzo[g]indazol-2-yl)benzene­sulfonamide ethanol monosolvate

In the title compound ethanol monosolvate, C₂₃H₂₁N₃O₂S·C₂H₅OH, the dihydro­pyrazole ring is twisted about the Csp³—Csp³ bond. Nevertheless, the ring approximates a plane (r.m.s. deviation for the fitted atoms = 0.132 Å) and forms dihedral angles of 5.80 (13) and 12.29 (12)°, respectively, with the fused- and sulfonamide-benzene rings. As the dihydro­pyrazole C-bound phenyl group is roughly perpendicular to the dihydro­pyrazole ring [dihedral angle = 74.04 (15)°; the amino group is orientated to the same side of the mol­ecule], to a first approximation, the mol­ecule has a stunted T-shape. The cyclo­hexene ring adopts a half-chair conformation with the methyl­ene C atom connected to the dihydro­pyrazole ring lying 0.665 (4) Å out of the plane of the five remaining atoms (r.m.s. deviation = 0.050 Å). The components of the asymmetric unit are connected by an O—H...O hydrogen bond. Further links between mol­ecules leading to a three-dimensional architecture are of the type N—H...O.

4-Nitro-N-[(E)-thio­phen-2-yl­methyl­idene]aniline

In the title compound, C₁₁H₈N₂O₂S, there is a twist in the mol­ecule, with the dihedral angle between the five- and six-membered rings being 31.77 (9)°. The nitro group is slightly twisted out of the plane of the benzene ring to which it is attached [O—N—C—C torsion angle = 9.0 (3)°]. The S and N atoms are syn. In the crystal, supra­molecular layers parallel to (-204) are formed by C—H...O and C—H...N inter­actions. These layers are connected into a three-dimensional architecture by π–π inter­actions occurring between centrosymmetrically related benzene rings [centroid–centroid distance = 3.6020 (11) Å].

(3Z)-1,1,1-Trifluoro-4-phenyl-4-[(2-{[(1Z)-4,4,4-trifluoro-3-oxo-1-phenyl­but-1-en-1-yl]amino}­eth­yl)amino]­but-3-en-2-one

In the title compound, C₂₂H₁₈F₆N₂O₂, the five atoms comprising each O=C—C=C—N fragment are almost coplanar (the r.m.s. deviation for the fitted atoms being 0.008 and 0.002 Å) and form a dihedral angle of 47.70 (12)°. The phenyl ring attached to each of the O=C—C=C—N fragments is twisted out of the respective plane with dihedral angles of 64.46 (11) and 61.82 (10)°, respectively. An almost orthogonal relationship for the phenyl rings is indicated by the dihedral angle between them of 78.19 (14)°. The conformation about each ethyl­ene bond is Z, which allows for the formation of intra­molecular N—H...O hydrogen bonds which close S(6) loops. The most prominent feature of the crystal packing are N—H...O hydrogen bonds that result in supra­molecular chains along the a axis. The F atoms of one –CF₃ groups are disordered over three sets of sites with site-occupation factors of 0.318 (4), 0.360 (10) and 0.322 (9).

8-Methyl-2-oxo-4-(thio­phen-2-yl)-1,2,5,6,7,8-hexa­hydro­quinoline-3-carbonitrile

In the title compound, C₁₅H₁₄N₂OS, the pyridinone ring in the fused-ring system is nearly planar (r.m.s. deviation = 0.011 Å) and the cyclo­hexene ring has a twisted half-boat conformation with the methyl­ene C atom adjacent to the methine C atom deviating by 0.592 (7) Å from the plane defined by the remaining five atoms (r.m.s. deviation = 0.108 Å). The thienyl ring is disordered over two almost coplanar positions of opposite orientation in a 0.649 (4):0.351 (4) ratio, and forms dihedral angles of 51.4 (3) (major component) and 54.2 (3)°, respectively, with the pyridinone ring. In the crystal, inversion-related mol­ecules associate via an eight-membered {...HNCO}₂ synthon and these are linked into a linear supra­molecular chain along the a axis by weak π–π inter­actions that occur between centrosymmetrically related pyridinone rings [centroid–centroid distance = 3.889 (2) Å].

(2E)-2-(Thio­phen-2-yl­methyl­idene)-1,2,3,4-tetra­hydro­naphthalen-1-one

In the title compound, C₁₅H₁₂OS, the cyclo­hexene ring has a twisted boat conformation with the C atom between the ketone and methyl­ene atom and this methyl­ene C atom lying 0.280 (3) and 0.760 (3) Å, respectively, from the plane through the remaining four atoms (r.m.s. deviation = 0.004 Å). The dihedral angle between the benzene and thio­phene rings [21.64 (9)°] indicates an overall twist in the mol­ecule. The thio­phene S and ketone O atoms are anti, an orientation that allows the close approach of these atoms [3.3116 (17) Å] in the crystal structure and which leads to the formation of helical supra­molecular chains along the c axis.

2-Hy­droxy-2-trifluoro­methyl-3,4-dihydro-2H-1-benzopyran-4-one

The heterocyclic ring in the title compound, C₁₀H₇F₃O₃, has a half-boat conformation with the hy­droxy-bearing C atom lying 0.595 (3) Å out of the plane of the five remaining atoms (r.m.s. deviation = 0.022 Å) in the direction of the hy­droxy O atom. Linear supra­molecular chains along the a axis, sustained by O—H...O hydrogen bonds between the hy­droxy H and ketone O atoms, feature in the crystal packing. These chains are connected into a three-dimensional architecture by C—H...O and C—H...F contacts.

2-[1-(1-Oxoindan-2-yl)eth­yl]indan-1-one

In the title compound, C₂₀H₁₈O₂, the fused-ring systems are essentially planar (r.m.s. deviations of the nine fitted atoms = 0.009 and 0.027 Å) and exhibit an orthogonal relationship [dihedral angle = 79.83 (5)°]. To a first approximation, the ketone-O atoms are directed to opposite sides of the mol­ecule. A three-dimensional architecture arises in the crystal packing owing to C—H...O, C—H...π and π–π inter­actions [between centrosymmetrically related benzene rings with centroid–centroid distance = 3.7647 (10) Å].

4-(4-Bromo­phen­yl)-8-methyl-2-oxo-1,2,3,4,4a,5,6,7-octa­hydro­quinoline-3-carbonitrile

In the title compound, C₁₇H₁₇BrN₂O, the N-containing ring adopts an envelope conformation with the C atom carrying the phenyl ring displaced by −0.531 (9) Å from the plane defined by the remaining five atoms (r.m.s. deviation = 0.0099 Å). The benzene ring is almost orthogonal to the ring to which it is attached, the C_CN—C—C_Ph—C_Ph torsion angle being −101.3 (7)°. The cyclo­hexene ring is disordered over two conformations in a statistical ratio. The most prominent inter­actions in the crystal are pairs of N—H...O hydrogen bonds between inversion-related mol­ecules. The resulting dimers are linked into a three-dimensional architecture by C—H...N, C—H...Br and C—H...π inter­actions.

4-Methyl-2-(2-nitro­benzene­sulfon­amido)­penta­noic acid

In the title compound, C₁₂H₁₆N₂O₆S, the S atom adopts a distorted tetra­hedral geometry with an O—S—O angle of 119.76 (13)°. The nitro group is twisted by 35.34 (2)° with respect to the aromatic ring; it accepts an N—H...O hydrogen bond, resulting in a S(7) motif. In the crystal, N—H...O and O—H...O hydrogen bonds connect the mol­ecules into an infinite chain along the a axis. The methyl C atoms of the isopropyl group are disordered in a 1:1 ratio.

2-Benzene­sulfonamido-3-methyl­butyric acid

In the crystal structure of the title compound, C₁₁H₁₅NO₄S, two independent mol­ecules are present per asymmetric unit; they are dimerized through O—H...O hydrogen bonds between their carb­oxy groups to generate R₂²(8) loops. An intra­molecular N—H...O link in one of the mol­ecules closes an S(5) ring. The dimers are linked by N—H...O and C—H...O hydrogen bonds to form a three-dimensional network. The C atoms of the isopropyl group of one of the mol­ecules are disordered over two orientations in a 3:1 ratio.

Ethyl 2-benzene­sulfonamido-4-methyl­penta­noate

In the title compound, C₁₄H₂₁NO₄S, the O—S—O angle is 120.06 (11)°, with the S atom adopting a distorted tetra­hedral geometry. In the crystal, N—H...O hydrogen bonds connect the mol­ecules along the a axis, generating an infinite chain. The disordered C atoms of the isobutyl group were refined with the C—C distances restrained to 1.52 (1) Å and the occupancy ratio refined to 0.504 (3):0.496 (3).

1-(Benzotriazol-1-yl)-2-bromoethanone

In the title compound C₈H₆BrN₃O, the benzotriazole ring is essentially planar (r.m.s. deviation = 0.0034 Å) and the bromo­acetyl unit is twisted at a dihedral angle of 15.24 (16)° with respect to it. In the crystal, pairs of C—H...O hydrogen bondings result in the formation of inversion dimers, forming R₂²(12) rings, which are connected by further C—H...O inter­actions into chains extending along the b-axis direction.

1-(1H-1,2,3-Benzotriazol-1-yl)-2-(4-meth­oxy­phen­yl)ethanone

In the title compound, C₁₅H₁₃N₃O₂, the dihedral angle between the benzotriazole ring system (r.m.s. deviation = 0.0124 Å) and the benzene ring is 76.21 (3)°. The meth­oxy C atom deviates from its benzene ring plane by 0.063 (2)Å. In the crystal, inversion dimers linked by pairs of C—H...O hydrogen bonds generate R₂²(12) loops.

Ethyl (Z)-2-chloro-2-[2-(4-meth­oxy­phenyl)hydrazin-1-yl­idene]acetate

The mol­ecule of the title compound, C₁₁H₁₃ClN₂O₃, is planar (r.m.s. deviation = 0.0587 Å for non-H atoms) and adopts a Z conformation about the C=N double bond. In the crystal, mol­ecules are linked via an N—H...O hydrogen bond, forming zigzag chains propagating along [010]. These chains are consolidated by C—H...O hydrogen bonds.

(Z)-Ethyl 2-chloro-2-[2-(4-methyl­phen­yl)hydrazinyl­idene]acetate

The mol­ecule of the title compound, C₁₁H₁₃ClN₂O₂, is approximately planar (r.m.s. deviation = 0.099 Å for non-H atoms) and adopts a Z conformation about the C=N double bond. In the crystal, mol­ecules are linked by N—H...O and C—H...O hydrogen bonds to the same O-atom acceptor, forming zigzag chains propagating along [010]. These inter­actions give rise to R₂¹(6) loops.