In the title compound, C13H13NO3·H2O, the dihedral angle between the ethyl ester group [C-C-O-C(=O); maximum deviation = 0.003 (2) Å] and the quinoline ring system is 7.94 (12)°. The water solvent mol-ecule is linked to the title mol-ecule via O-H⋯O and O-H⋯N hydrogen bonds. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, forming chains propagating along [100].

The title compound, C27H29F3O5, is a liquid crystal (LC) and exhibits enanti-otropic SmA phase transitions. In the crystal, the dihedral angle between the 2H-chromene ring system and the benzene ring is 62.97 (2)°. The three F atoms of the -CF3 group are disordered over two sets of sites with occupancy factors 0.71 (4):0.29 (4). In the crystal, pairs of C-H⋯O hydrogen bonds form inversion dimers and generate R 2 (2)(10) rings. The structure also features C-H⋯F and C-H⋯π inter-actions along [100] and [010], respectively.

Crystals of the title compound, C14H8Cl6O4S, are twinned by inversion, with unequal components [0.85 (3):0.15 (3)]. The asymmetric unit contains two independent mol-ecules that are related by a pseudo-inversion center. The Car-O [1.393 (9) and 1.397 (9) Å] and ester S-O bond lengths [1.600 (5) and 1.590 (5) Å] of both mol-ecules are comparable to the structurally related 2,3,5,5-trichloro-biphenyl-4-yl 2,2,2-trichloro-ethyl sulfate. The dihedral angles between the benzene rings in the two mol-ecules are 37.8 (2) and 35.0 (2)°.

In the title compound, C26H23FN6S, the pyrazole ring has an envelope conformation, with the methine C atom being the flap atom. The thio-urea group is close to being coplanar with the pyrazole N atoms [N-N-C-S torsion angle = 176.78 (15)°], which allows for an intra-molecular N-H⋯N hydrogen bond; the connected triazole ring is nearly coplanar with this ring [N-C-C-N = -172.65 (19)°]. There is a significant twist between the pyrazole ring and attached fluoro-benzene ring [N-C-C-C = -18.8 (3)°] and a greater twist between triazole and attached tolyl ring [dihedral angle = 58.25 (14)°]. In the crystal, supra-molecular chains aligned along [40,10] are consolidated by π-π inter-actions between the triazole and phenyl rings [centroid-centroid distance = 3.7053 (13) Å].

In the title compound, C28H23FN6S, the pyrazole ring adopts an envelope conformation, with the methine C atom being the flap atom. With respect to this ring, the 2-thienyl, triazole and fluoro-benzene rings are approximately coplanar, coplanar and perpendicular, respectively [dihedral angles = 8.56 (17), 6.03 (19) and 73.1 (2)°, respectively] so that to a first approximation the mol-ecule has a T-shape. In the crystal, mol-ecules are consolidated into a three-dimensional architecture by C-H⋯F (involving a bifurcated F atom), C-H⋯S and C-H⋯π inter-actions.

In the xanthene ring system in the title compound, C19H18O4, the 4H-pyran ring has a maximum deviation of 0.110 (2) Å from planarity and the cyclo-hexene ring exhibits a puckered conformation [puckering parameters Q T = 0.452 (3) Å, θ = 57.0 (4) and ϕ = 131.7 (4)°]. The cyclo-hexene ring attached to the xanthene system adopts an envelope conformation, with the middle of the three methylene C atoms as the flap atom. In the crystal, O-H⋯O and C-H⋯O hydrogen bonds form infinite chains of R 1 (2)(6) ring motifs along [100] with the xanthene groups arranged in an alternating zigzag manner.

The mol-ecular structure of the title compound, C28H22N2O6S2·0.5CH3COOH, is built up from three fused rings, two six and one eight membered. The eight-membered ring shows a boat conformation and the dihedral angle between the two benzene groups attached thereto is 66.43 (11)°, resulting in a V-shaped geometry. Two tosyl substituents are bound to the N atoms. The planes through the tolyl rings are roughly perpendicular, as indicated by the dihedral angle of 82.44 (12)°. In the crystal, the mol-ecule and its inversion-related symmetry-equivalent are linked to the acetic acid solvent mol-ecule by non-classical O-H⋯O and C-H⋯O hydrogen bonds. Two half-occupied acetic acid solvent mol-ecules are disordered at the same site and linked by a center of symmetry.

In the title compound, C18H23N5, the imidazole ring makes a dihedral angles of 3.96 (8) and 19.02 (8)°, respectively, with the pyrazine and benzene rings while the dihedral angle between the pyrazine and benzene rings is 16.96 (7)°. In the crystal, mol-ecules are linked via N-H⋯N hydrogen bonds, forming chains along [010]. These chains are linked by C-H⋯N hydrogen bonds, forming two-dimensional networks lying parallel to (001).

In the title compound, C14H8Cl2N4O2, the pyrazine rings are orthogonal to the benzene ring, making dihedral angles of 88.42 (8) and 89.22 (8)°. The Cl atoms attached to the pyrazine rings deviate by -0.0597 (5) and 0.0009 (5) Å from the ring plane. The crystal structure features C-H⋯N hydrogen bonds.

In the title mol-ecular salt, C6H9N2 (+)·C7H5O3 (-), the dihedral angle between the benzene ring and the CO2 group in the anion is 6.1 (2)°. In the crystal, the cation and anion are linked by N-H⋯O and C-H⋯O hydrogen bonds, and the anions are connected by O-H⋯O hydrogen bonds, forming a three-dimensional network.