Bis[6-(1H-benzimidazol-2-yl-κN³)pyridine-2-carboxyl­ato-κ²N,O]cobalt(II) dihydrate

In the title compound, [Co(C₁₃H₈N₃O₂)₂]·2H₂O, the Co^II atom has a distorted octa­hedral environment defined by four N atoms and two O atoms from two 6-(1H-benzimidazol-2-yl)pyridine-2-carboxyl­ate ligands. In the crystal, the complex mol­ecules and uncoordinated water mol­ecules are linked via N—H...O and O—H...O hydrogen bonds, forming a two-dimensional supra­molecular structure parallel to (010). π–π inter­actions are present between the imidazole, pyridine and benzene rings [centroid–centroid distances = 3.528 (2), 3.592 (2), 3.680 (2) and 3.732 (3) Å].

catena-Poly[[[tetra­aqua­copper(II)]-μ-4,4′-bipyridyl-κ²N:N′] tetra­fluorido­succinate tetra­hydrate]

In the title compound, {[Cu(C₁₀H₈N₂)(H₂O)₄](C₄F₄O₄)·4H₂O}_n, the Cu^II atom adopts an elongated octa­hedral geometry because of the Jahn–Teller effect. Both cation and anion have crystallographic twofold rotation symmetry with the twofold axes passing through the Cu and N atoms and through the midpoint of the central C—C bond. The 4,4′-bipyridyl ligand links the Cu^II atoms into a linear chain along the b axis. O—H...O hydrogen-bonding inter­actions between the cationic chains and the tetra­fluorido­succinate anions and the free water mol­ecules generate a three-dimensional supra­molecular network.

8,10-Diiodo-2,6-dioxo-4λ³-ioda-3,5-dioxatricyclo­[5.3.1.0^4,11]undeca-1(11),7,9-triene-9-carb­oxy­lic acid

In the title compound, C₉HI₃O₆·2H₂O, the mol­ecule is located on a twofold axis that gives rise to disorder of the carboxyl group. This disorder is correlated with the disorder of one of the H atoms of the water mol­ecule. The carboxyl group is twisted relative to the attached benzene ring by 75.1 (4)°. The intra­molecular I...O distance is 2.112 (6) Å. Mol­ecules are linked via O—H...O hydrogen bonding, C—I...O halogen bonding, with I...O distances in the range 3.156 (5)–3.274 (6) Å, and dipolar C=O...C=O inter­actions between the carboxyl and carboxyl­ate groups, with an O...C distance of 2.944 (10) Å.

4,4′-Bipyrid­yl–4,4′-(hy­droxy­methyl­ene)dibenzoic acid (1/1)

In the title 1:1 co-crystal, C₁₀H₈N₂·C₁₅H₁₂O₅, strong inter­molecular O—H...N hydrogen bonds link alternating mol­ecules of 4,4′-(hy­droxy­methyl­ene)dibenzoic acid and 4,4′-bipyridyl into zigzag chains in [501]. The crystal packing also exhibits π–π inter­actions between the 4,4′-bipyridyl rings of neighbouring chains [centroid–centroid distance = 3.608 (3) Å] and weak C—H...O hydrogen bonds.

Bis(dimethyl­ammonium) 3,3′-dicarb­oxy-5,5′-(5,7,12,14-tetra­oxo-6,13-diaza­tetra­cyclo­[6.6.2.0^4,16.0^11,15]hexa­deca-1,3,8,10,15-penta­ene-6,13-di­yl)dibenzoate dihydrate

The title compound, 2C₂H₈N⁺·C₃₀H₁₂N₂O₁₂²⁻·2H₂O, comprises dimethyl­ammonium cations, 3,3′-dicarb­oxy-5,5′-(5,7,12,14-tetra­oxo-6,13-diaza­tetra­cyclo­[6.6.2.0^4,16.0^11,15]hexa­deca-1,3,8,10,15-penta­ene-6,13-di­yl)dibenzoate dianions and water mol­ecules. The dianion is situated on a crystallographic inversion centre. Two very strong symmetry-restricted O...H...O hydrogen bonds are present which are situated about the crystallographic inversion centres. In one of these hydrogen bonds, the H atom is situated at its centre, while in the other one the H atom is disordered about its centre. Both H atoms are involved in the chain-like C²₂(16) motif, and not in a more common motif R²₂(8) that is composed of a pair of hydrogen carboxyl­ates with the H atoms situated about the centre between the pair of O atoms. In the crystal, inter­action of these hydrogen bonds results in formation of anionic layers of dianions parallel to (-111). The water mol­ecules donate their H atoms to one of two of the carboxyl­ate O atoms, forming strong hydrogen bonds. The dimethyl­ammonium donates a bifurcated hydrogen bond to an oxo group of the dianion, forming weak hydrogen bonds. All the hydrogen bonds form a three-dimensional hydrogen-bonded network.