2,3,5,6-Tetra­methyl­pyrazine–p-nitro­phenol (1/2)

In the title complex, C₈H₁₂N₂·2C₆H₅NO₃, one 2,3,5,6-tetra­methyl­pyrazine and two p-nitro­phenol mol­ecules form a centrosymmetric unit. Intermolecular O—H...N and weak C—H...O hydrogen bonds are observed in the structure, leading to the formation of a two-dimensional network.

Tetra­methyl­pyrazine–endo-norbornene-cis-5,6-di­carboxyl­ic acid (1/2)

In the title complex, 2C₉H₁₀O₄·C₈H₁₂N₂, there is an inversion centre at the centre of the 2,3,5,6-tetra­methyl­pyrazine mol­ecule, which is linked to two endo-norbornene-cis-5,6-di­carboxyl­ic acid mol­ecules via O—H...N hydrogen bonds. In the crystal structure, O—H...O and O—H...N hydrogen bonds propagate a one-dimensional zigzag chain, which is extended into layers when combined with longer C—H...O hydrogen bonds.

6,6′-Dioxo-2,2-bi(7-oxatri­cyclo­[3.2.1.1^3,8]­nonane)-4,4′-di­carboxyl­ic acid

The title mol­ecule, C₁₈H₁₈O₈, has C₂ molecular symmetry. In the crystal structure, each mol­ecule is connected to four neighbours via intermolecular O—H...O hydrogen bonds to form a two-dimensional network parallel to (100).

Diaqua­dibenzimidazole­bis(5-fluoro-2,4-dioxo-1,2,3,4-tetra­hydro­pyrimidine-1-acetato)cadmium(II)

In the title centrosymmetric compound, [Cd(C₆H₄FN₂O₄)₂(C₇H₆N₂)₂(H₂O)₂], the cadmium(II) cation is coordinated by one O atom from each 5-fluoro-2,4-dioxo-1,2,3,4-tetra­hydro­pyrimidine-1-acetate anion, one N atom from each benzimidazole ligand and two water mol­ecules. The geometry around the cadmium(II) cation, which is located on a center of inversion, is distorted octa­hedral. Mol­ecules, which function as supramolecular blocks, are linked by inter­molecular N—H...O and O—H...O hydrogen bonds into a three-dimensional supramolecular network, which is reinforced by π–π inter­actions.