In the title compound, [Cu(C(13)H(14)BrNO(3))(C(12)H(8)N(2))]·2H(2)O, the Cu(II) atom is penta-coordinated in a square-pyramidal geometry. The crystal packing is stabilized by O-H⋯O hydrogen bonds.

The two benzene rings in the cation of the title compound, C(15)H(18)N(4)O(2) (2+)·2NO(3) (-)·2H(2)O, are almost perpendicular [dihedral angle = 91.6 (2)°]. In the crystal, the components are linked by O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds.

In the title compound, (C(6)H(9)N(2))(2)[Zr(C(7)H(3)NO(4))(3)]·2H(2)O, the Zr(IV) atom is nine-coordinated by three pyridine-2,6-dicarboxyl-ate ligands in a distorted tricapped trigonal-prismatic ZrN(3)O(6) environment. The crystal packing is stabilized by inter-molecular N-H⋯O and O-H⋯O hydrogen bonds.

The title compound, C(6)H(8)N(4)O(3)·2H(2)O, which crystallized as a dihydrate, has two almost planar segments viz. the pyrimidine ring and the C-N-C(=O)-C group [maxmum deviations of 0.020 (2) and 0.014 (2) Å, respectively], with a dihedral angle of 87.45°. In the crystal, the components are linked by O-H⋯O and N-H⋯O hydrogen bonds.

In the title compound, C14H14O4, the prop-2-yn-yloxy O-C-C C plane [maximum deviation = 0.0116 (12) Å] forms a dihedral angle of 78.44 (9)° with the benzofuran-3(2H)-one ring system. In the crystal, mol-ecules are linked by O-H⋯O hydrogen bonds, forming a tape along the a-axis direction. C-H⋯O inter-actions are observed between the tapes.

In the crystal structure of the title compound, C(17)H(21)N(3)O(2)·2H(2)O, water mol-ecules are mutually O-H⋯O hydrogen bonded and form infinite chains propagating along the b axis. Neighboring chains are linked by the quinazoline mol-ecules by means of O-H⋯O=C hydrogen bonds, forming a two-dimensional network.

In the hydrated title salt, C(5)H(7)N(2) (+)·C(10)H(6)IO(4)S(-)·2H(2)O, the component species are linked by O-H⋯O and N-H⋯O hydrogen bonds, forming an infinite three-dimensional framework.

The crystal structure of N-(3,9-dimethyl-4-phenyl-2,5-dioxo-3,4-dihydro-2H,5H-pyrano[3,2-c]chromen-3-yl)-N-methylbenzamide methanol monosolvate, C(28)H(23)NO(5)·CH(3)OH, has been determined at room temperature by X-ray diffraction. Structural parameters are discussed with reference to ab initio calculations.

In the crystal of the title compound, C(18)H(22)N(2)O(4)S·2H(2)O, mol-ecules are linked into a one-dimensional chain structure by C-H⋯O, N-H⋯O, O-H⋯O and O-H⋯N hydrogen bonds.

The mol-ecule of the title compound, C(16)H(10)N(2)OS, is approximately planar, the dihedral angle between the 1,3-benzothia-zolo[3,2-a]imidazol-3(2H)-one and the benzyl-idene moieties being 4.10 (8)°. A weak intra-molecular C-H⋯S inter-action generates an S(6) ring. No inter-molecular hydrogen bonds are observed in the crystal structure.