10,11-Di­hydro­cinchonan-9-ol

Arising from a hydrogen bond between the OH group of one mol­ecule and the quinuclidine N atom of an adjacent mol­ecule, mol­ecules of the title compound, C₁₉H₂₄N₂O, [also known as (3R,8S,9R)-10,11-di­hydro­cinchonidine] are linked [O...N = 2.749 (4) Å] into a helical chain that runs along the shortest axis of the orthorhombic unit cell. The compound is isostructural with cinchonidine (which has a vinyl group instead of the ethyl group), whose structure has been described in detail [Oleksyn (1982). Acta Cryst. B38, 1832–1834].

1,4-Diazo­niabi­cyclo­[2.2.2]­octane di­aqua­bis­(pyrazole-3,5-di­carboxyl­ato)­zincate(II) dihydrate

The title compound, (C₆H₁₄N₂)[Zn(C₅H₂N₂O₄)₂(H₂O)₂]·2H₂O, consists of di­aqua­bis­(pyrazole-3,5-di­carboxyl­ato)­zincate(II) dianions, 1,4-diazo­niabi­cyclo­[2,2,2]­octane dications and water mol­ecules of crystallization, linked by O—H...O and N—H...O hydrogen bonds into a three-dimensional network. The geometry around the Zn²⁺ centre is octahedral.

Di­aqua­(benz­imidazole)(nitrato-κO)(1,10-phenanthroline)­cadmium(II) nitrate

In the crystal structure of the title compound, [Cd(NO₃)(C₇H₆N₂)(C₁₂H₈N₂)(H₂O)₂]NO₃, the phenanthroline-chelated Cd atom is bonded to the benz­imidazole, two water mol­ecules and a monodentate nitrate group in a six-coordinate octahedral geometry. The cation interacts with the nitrate anion to form a three-dimensional hydrogen-bonding network.

4,4'-Bipyridinium bis(3,5-di­carboxy­benzoate) benzene-1,3,5-tri­carboxyl­ic acid hexahydrate

The asymmetric unit of the title compound, C₁₀H₁₀N₂²⁺·2C₉H₅O₆^-·C₉H₆O₆·6H₂O, consists of half of a bipyridinium cation, one singly deprotonated 3,5-di­carboxy­benzoate anion, one half of a benzene-1,3,5-tri­carboxyl­ic acid mol­ecule and three water mol­ecules that are linked by hydrogen bonds into a network structure. The two halves of the bipyridinium cation are related by an inversion centre and those of the benzene-1,3,5-tri­carboxyl­ic acid mol­ecule by twofold rotation.

6-(2,4-Difluoro­phen­yl)-3-(4-meth­oxyphenyl)-7H-1,2,4-triazolo[3,4-b][1,3,4]thia­diazine

In the title compound, C₁₇H₁₂F₂N₄OS, the thia­diazine ring is non-planar and adopts a half-chair conformation. The crystal packing is stabilized by C—H...N, C—H...O and C—H...F inter­molecular hydrogen-bonding inter­actions.