The title compound, C16H13Cl2F3N2, exists in an E conformation with respect to the C=N bond [1.2952 (11) Å] and the C—N—N=C torsion angle is 175.65 (8)°. The dihedral angle between the benzene rings is 42.09 (4)°. An intra­molecular C—H⋯F hydrogen bond generates an S(6) ring. In the crystal, the mol­ecules are linked into [101] chains by C—H⋯F hydrogen bonds.

In the cation of the title compound, C9H12NO2 +·Cl−, the dihedral angle between the 2-oxoethanaminium N—C—C(=O)– plane [maximum deviation = 0.0148 (12) Å] and the benzene ring is 7.98 (8)°. The meth­oxy group is approximately in-plane with the benzene ring, with a C—O—C—C torsion angle of −2.91 (18)°. In the crystal, the cations and chloride anions are connected by N—H⋯Cl and C—H⋯Cl hydrogen bonds, forming a layer parallel to the bc plane. A C—H⋯π inter­action further links the layers.

In the title compound, C15H12F2N2O, the dihedral angle between the two benzene rings is 48.73 (8)°. The hydrazine group is twisted slightly, with a C—N—N—C torsion angle of 172.48 (12)°. In the crystal, mol­ecules are connected by strong N—H⋯O and weak C—H⋯O hydrogen bonds, forming supra­molecular chains along the c axis. The structure is consolidated by π–π [centroid–centroid separation = 3.6579 (10) Å] and C—H⋯π inter­actions.

In the title compound, C15H9Cl2N3O, an intra­molecular C—H⋯O inter­action generates an S(7) ring motif. The cyclo­penta-1,3-diene ring forms dihedral angles of 1.93 (6) and 2.78 (6)° with its attached benzene rings. In the crystal, mol­ecules are linked by C—H⋯N and C—H⋯O hydrogen bonds, thereby forming layers lying parallel to the ac plane. The crystal also features a π–π inter­action with a centroid–centroid distance of 3.5612 (6) Å.

In the crystal of the title molecular salt, 2C6H7FN+·SO4 2−, the cations and anions are linked by N—H⋯O and C—H⋯O hydrogen bonds into sheets parallel to the ab plane. The crystal studied was found to be a racemic twin with a 0.50 (10):0.50 (10) domain ratio.

In the title compound, C10H13NO, the C—C—C—C torsion angle formed between the benzene ring and the butan-2-one oxime unit is 73.7 (2)°, with the latter lying above the plane through the benzene ring. In the crystal, inter­molecular O—H⋯N hydrogen bonds link pairs of mol­ecules into dimers, forming R 2 2(6) ring motifs which are stacked along the a axis.

In the title compound, C15H17N3O, the 1H-imidazo[4,5-c]quinoline ring system is approximately planar, with a maximum deviation of 0.036 (1) Å. The C—N—C—C torsion angles formed between this ring system and the isobutyl unit are −99.77 (16) and 79.71 (17)°. In the crystal, inter­molecular C—H⋯O hydrogen bonds link the mol­ecules into chains along the c axis.

In the title compound, C11H19NO4, the piperidine ring adopts a chair conformation. In the crystal, mol­ecules are linked by inter­molecular O—H⋯O and C—H⋯O hydrogen bonds, forming a layer parallel to the bc plane.

In the title compound, C21H20N4O2, the statistically planar 1H-limidazole ring [maximum deviation = 0.003 (1) Å] makes dihedral angles of 1.33 (9) and 8.23 (7)°, respectively, with the essentially planar fused pyridine ring [maximum devation = 0.018 (1) Å] and the pendant benzene ring, which is attached to the pyridine ring by an —NH— group. An intra­molecular C—H⋯N inter­action, which generates an S(6) ring, helps to estalish the mol­ecular conformation. In the crystal, the mol­ecules are linked by N—H⋯O, C—H⋯O and O—H—N hydrogen bonds, which generate bifurcated R 1 2(6) and R 2 2(9) ring motifs, resulting in supra­molecular [001] chains. The crystal structure also features weak π–π stacking [centroid–centroid distance = 3.5943 (9) Å] and C—H⋯π inter­actions.

The asymmetric unit of the title compound, C15H15NO, contains two independent mol­ecules, both of which exist in trans configurations with respect to the C=N bonds [1.278 (2) and 1.279 (2) Å]. In each mol­ecule, intra­molecular O—H⋯N hydrogen bonds generate S(6) ring motifs. In one mol­ecule, the benzene rings form a dihedral angle of 13.38 (9)°, while in the other mol­ecule the dihedral angle is 30.60 (10)°. In the crystal, the two independent mol­ecules are linked via weak inter­molecular C—H⋯O hydrogen bonds.

The title mol­ecule, C13H8Cl3NO, exists in a trans configuration with respect to the C=N bond [1.278 (2) Å]. The benzene rings form a dihedral angle of 24.64 (11)°. The mol­ecular structure is stabilized by an intra­molecular O—H⋯N hydrogen bond, which generates an S(6) ring motif. In the crystal, π–π stacking inter­actions [centroid–centroid distances = 3.6893 (14) Å] are observed.

In the title compound, C10H6F3N3, the imidazo[1,2-a]pyridine group is essentially planar with a maximum deviation of 0.021 (1) Å. The F atoms in the trifluoro­methyl group and the methyl H atoms are each disordered over two sets of sites with refined site occupancies of 0.68 (1):0.32 (1). In the crystal, mol­ecules are linked into infinite chains through two C—H⋯N inter­actions forming R 2 2(12) and R 2 2(8) hydrogen-bond ring motifs. These chains are stacked along the a axis.

There are two mol­ecules in the asymmetric unit of the title imidazole derivative, C20H16ClFN2OS2. In one mol­ecule, the dithiol­ane ring is disordered over two positions in a 0.849 (9):0.151 (10) ratio. The imidazole ring makes dihedral angles of 79.56 (9) and 18.45 (9)° with the 4-chloro­phenyl and 2-fluoro­phenyl rings, respectively, in one mol­ecule; in the other mol­ecule, the corresponding angles are 82.72 (9) and 17.39 (10)°. In the crystal, mol­ecules are linked by weak C—H⋯O inter­actions and these linked mol­ecules are stacked along the b axis by π–π inter­actions with a centroid–centroid distance of 3.4922 (11) Å. In addition, π–π inter­actions between the imidazole and 2-fluoro­phenyl rings are also observed, with centroid–centroid distances of 3.4867 (11) and 3.4326 (10) Å. The crystal is further consolidated by weak C—H⋯π inter­actions. Cl⋯S [3.5185 (8) Å], C⋯O [3.192 (3) Å] and C⋯C [3.326 (2)–3.393 (3) Å] short contacts are also observed.

In the title compound, C16H20N4, the 1H-imidazo[4,5-c]quinoline ring system is approximately planar, with a maximum deviation of 0.0719 (15) Å. An intra­molecular C—H⋯N hydrogen bond contributes to the stabilization of the mol­ecule, forming an S(6) ring motif. In the crystal, the mol­ecules are stacked along the b axis through weak aromatic π–π inter­actions between benzene and imidazole and benzene and pyridine rings [centroid–centroid distances = 3.6055 (10) and 3.5342 (10) Å, respectively].

In the title 1,2,4-oxadiazole derivative, C19H18ClN3O3, the 1,2,4-oxadiazole ring makes dihedral angles of 12.83 (8) and 4.89 (8)°, respectively, with the benzyl and 4-chloro­phenyl rings, while the dihedral angle between the benzyl and 4-chloro­phenyl rings is 11.53 (7)°. In the crystal, mol­ecules are linked by N—H⋯N hydrogen bonds into helical chains along the b axis. A weak C—H⋯π inter­action is also present.

In the title compound, C21H20ClN5·H2O, the 1H-imidazo[4,5-c]quinoline ring is approximately planar, with a maximum deviation of 0.0795 (7) Å, and it forms a dihedral angle of 7.65 (3)° with the chloro­phenyl ring. In the crystal, the components are linked into chains along the a axis via inter­molecular N—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds. One of the H atoms of the water mol­ecule is disordered over two positions with a site-occupancy ratio of 0.80 (4):0.20 (4).

In the title compound, C14H17N5, the 1H-imidazo[4,5-c]quinoline ring system is essentially planar, with a maximum deviation of 0.0325 (7) Å. In the crystal, a pair of inter­molecular N—H⋯N hydrogen bonds link neighbouring mol­ecules, forming an inversion dimer and generate an R 2 2(10) ring motif. These dimers are further connected into a chain along the b axis via inter­molecular C—H⋯N hydrogen bonds, resulting in an R 2 2(14) ring motif.

In the title compound, C14H14ClN3S, the imidazo[2,1-b][1,3,4]thia­diazole system is essentially planar, with a maximum deviation of 0.006 (2) Å. The dihedral angle between the imidazo[2,1-b][1,3,4]thia­diazole and chloro­phenyl rings is 5.07 (8)°. In the crystal, there are no classical hydrogen bonds but stabilization is provided by weak π–π [centroid–centroid distance = 3.5697 (11) Å] and C—H⋯π inter­actions.