(±)-(4aR,5R,8S,8aR)-8-(tert-Butyl­dimethyl­sil­yloxy)-2,5,8a-trimethyl-4a,5,8,8a-tetra­hydro­naphthalene-1,4-dione

In the title compound, C₁₉H₃₀O₃Si, both rings adopt a half-boat conformation. Overall, the mol­ecule approximates a U-shape as the cyclo-2-ene-1,4-dione and butyl­dimethyl­sil­yloxy substituents lie to the same side of the central cyclo­hexene ring; the methyl substituent lies to the other side of the mol­ecule. In the crystal, linear supra­molecular chains along the b axis are sustained by C—H...O inter­actions.

2-(2,4-Dichloro­phen­oxy­meth­yl)-5-(4-methyl­phen­yl)imidazo[2,1-b][1,3,4]thia­diazole

In the title compound, C₁₈H₁₃Cl₂N₃OS, the eight atoms comprising the central imidazo/thia­diazo­lethia­diazole residue are coplanar (r.m.s. deviation = 0.009 Å). The dihedral angle of 8.72 (13)° between the dichloro­benzene and tolyl rings reflects a twist about the O—C(benzene) bond; the C_m—O—C_b—C_b torsion angle = −168.5 (2)° (m = methyl­ene C and b is benzene C). Supra­molecular tapes along the b axis are found in the crystal structure which are mediated by π–π inter­actions occurring between centrosymmetrically related thia­diazole rings [inter-ring centroid distance = 3.6907 (16) Å] and between the benzene and tolyl rings [inter-ring centroid distance = 3.7597 (16) Å].

2,2-Dibenzyl­hydrazin-1-ium chloride

In the title salt, C₁₄H₁₇N₂⁺·Cl⁻, the central N atom is pyramidal (sum of bond angles = 330.9°) and there is a near orthogonal relationship between the benzene rings [dihedral angle = 89.95 (10)°]. The crystal packing features N—H...Cl hydrogen bonds, which lead to a supra­molecular undulating ribbon along the a axis comprising edge-shared eight-membered {...HNH...Cl}₂ synthons. The chains are connected into layers in the ab plane by C—H...π inter­actions.

5-(4-Fluoro­phen­yl)-3-(4-methyl­phen­yl)-4,5-dihydro-1H-pyrazole-1-carbothio­amide

The central pyrazole ring in the title compound, C₁₇H₁₆FN₃S, adopts an envelope conformation with the methine C atom bearing the 4-fluoro­phenyl substituent as the flap atom. Whereas the tolyl ring is slightly twisted out of the least-squares plane through the pyrazole ring [dihedral angle = 13.51 (11)°], the fluoro­benzene ring is almost perpendicular [dihedral angle = 80.21 (11)°]. The thio­amide group is almost coplanar with the N—N bond of the ring [N—N—C—N torsion angle = 1.2 (3)°] and the amine group forms an intra­molecular hydrogen bond with a ring N atom. In the crystal, supra­molecular double layers in the bc plane are formed via N—H...S, N—H...F and C—H...F inter­actions.

2-[5-(4-Fluoro­phen­yl)-3-(4-methyl­phen­yl)-4,5-dihydro-1H-pyrazol-1-yl]-4-phenyl-1,3-thia­zole

In the title compound, C₂₅H₂₀FN₃S, two independent mol­ecules comprise the asymmetric unit, which differ in the relative orientation of the fluoro­benzene ring with respect to the pyrazole ring to which it is attached [dihedral angles = 89.39 (17) and 75.23 (16)° in the two mol­ecules]. Each pyrazole ring adopts an envelope conformation with the methine C atom being the flap atom. There are additional twists in the mol­ecules, e.g. between the five-membered rings [dihedral angles = 18.23 (16) and 17.84 (16)°] and between the thia­zole and attached phenyl ring [10.26 (16) and 20.87 (15)°]. Overall, each mol­ecule has a T-shape. In the crystal, mol­ecules are connected into a three-dimensional architecture by weak C—H...π inter­actions.

3-(4-Chloro­phen­yl)-5-(4-fluoro­phen­yl)-4,5-dihydro-1H-pyrazole-1-carbothio­amide

In the title compound, C₁₆H₁₃ClFN₃S, the pyrazole ring adopts an envelope conformation with the methine C atom being the flap atom. The chloro- and fluoro­benzene rings are twisted out of the plane of the pyrazole ring [dihedral angles = 15.12 (11) and 80.55 (10)°, respectively]. The amine group is orientated towards a ring N atom, forming an intra­molecular N—H...N hydrogen bond. This H atom also forms a hydrogen bond to the F atom, which along with N—H...S hydrogen bonding leads to a supra­molecular chain along the c axis. Connections between chains of the type Cl...π lead to a layer in the bc plane.

(2E)-1-(2-Methyl-4-phenyl­quinolin-3-yl)-3-(3-methyl­thio­phen-2-yl)prop-2-en-1-one

In the title compound, C₂₄H₁₉NOS, the quinoline residue (r.m.s. deviation = 0.018 Å) is essentially orthogonal to both the phenyl [dihedral angle = 88.95 (8)°] and 2-thienyl [81.98 (9)°] rings. The carbonyl O atom lies to one side of the quinoline plane, the carbonyl C atom is almost coplanar and the remaining atoms of the chalcone residue lies to the other side, so that overall the mol­ecule has an L-shape. The conformation about the ethyl­ene bond [1.340 (2) Å] is E. In the crystal, a supra­molecular chain with the shape of a square rod aligned along the b-axis direction is sustained by C—H...π inter­actions, the π-systems being the heterocyclic rings.

(2E)-1-(2,4-Dimethyl­quinolin-3-yl)-3-phenyl­prop-2-en-1-one

Two independent mol­ecules comprise the asymmetric unit of the title compound, C₂₀H₁₇NO, which differ in the orientation of the terminal phenyl ring with respect to the quinoline ring [the dihedral angles are 75.72 (11) and 84.53 (12)° for the two mol­ecules]. The conformation about each of the ethyl­ene bonds [1.329 (3) and 1.318 (3) Å] is E. The crystal structure features a combination of C—H...N, C—H...π and π–π contacts [inter-centroid between the phenyl ring and the quinoline benzene ring is 3.6024 (19) Å], generating a three-dimensional network.

2-Methyl­sulfanyl-1,2,4-triazolo[1,5-a]quinazoline-5(4H)-thione

In the title compound, C₁₀H₈N₄S₂, comprising fused six-, six- and five-membered rings, the mol­ecule is close to being planar (r.m.s. deviation of the non-H atoms = 0.041 Å). The S-bound methyl group is folded away from the single N atom of the triazole ring and the NH group of the six-membered ring, allowing for the formation of centrosymmetric eight-membered {...HNCN}₂ synthons in the crystal. The resulting inversion dimers are connected into supra­molecular stacks aligned along the b-axis direction by π–π inter­actions [centroid–centroid distances = 3.6531 (12) and 3.7182 (12) Å].

Ethyl 2-amino-4-(4-bromo­phen­yl)-6-meth­oxy-4H-benzo[h]chromene-3-carboxyl­ate

In the title compound, C₂₃H₂₀BrNO₄, the pyran ring has a flattened boat conformation with the O and methine C atoms lying to one side of the plane [0.160 (5) and 0.256 (6) Å, respectively] defined by the remaining atoms. Nevertheless, the 4H-benzo[h]chromene ring system approximates a plane (r.m.s. deviation = 0.116 Å) with the bromo­benzene ring almost perpendicular [dihedral angle = 83.27 (16)°] and the ester group coplanar [C—C—C—O = 3.4 (5)°]; the meth­oxy substituent is also coplanar [C—O—C—C = 174.5 (3)°]. In addition to an intra­molecular N—H...O(ester carbon­yl) hydrogen bond, the ester carbonyl O atom also forms an inter­molecular N—H...O hydrogen bond with the second amine H atom, generating a zigzag supra­molecular chain along the c axis in the crystal packing. The chains are linked into layers in the bc plane by N—H...Br hydrogen bonds, and these layers are consolidated into a three-dimensional architecture by C—H...π inter­actions.

4-Dimethyl­amino-1-(4-meth­oxy­phen­yl)-2,5-dioxo-2,5-dihydro-1H-pyrrole-3-carbonitrile

In the title compound, C₁₄H₁₃N₃O₃, a twist occurs, as seen in the dihedral angle of 53.60 (12)° between the pyrrole and benzene rings. A three-dimensional architecture is formed in the crystal whereby layers of mol­ecules in the ac plane are connected by C—H...O and C—H...π inter­actions.