Bis(μ-L-arginine-κ³N²,O:O′)bis­(L-arginine-κ²N²,O)tetra-μ-chlorido-tetra­chlorido­tetra­copper(II)

The title compound, [Cu₄Cl₈(C₆H₁₄N₄O₂)₄], contains four mol­ecules in the asymmetric unit. In the mol­ecular structure, each of the four Cu²⁺ ions binds to three Cl atoms, one N atom and one O atom, resulting in distorted square-pyramidal coordination environments. The molecular structure is stabilized by weak C—H...O and N—H...Cl hydrogen bonds. The crystal structure exhibit weak inter­molecular N—H...O, C—H...O and N—H...Cl inter­actions, generating a three-dimensional network.

catena-Poly[[bis­(nitrato-κ²O,O′)barium]-bis­(μ-L-histidine-κ³O,O′:O]

In the polymeric title compound, [Ba(NO₃)₂(C₆H₉N₃O₂)₂]_n, the Ba^II atom is located on a crystallographic twofold axis and is coordinated by ten O atoms. Six are derived from two zwitterionic L-histidine mol­ecules that simultaneously chelate one Ba^II atom and bridge to another. The remaining four O atoms are derived from two chelating nitrates. The mol­ecules assemble to form a chain along [010]. In the crystal, chains are linked via N—H...O and N—H...N hydrogen bonds, generating a three-dimensional network.

Di-μ-hydroxido-κ⁴O:O-di-μ-perchlorato-κ⁴O:O′-bis­[(2,2′-bi­pyridine-κ²N,N′)copper(II)]

In the title binuclear copper(II) complex, [Cu₂(ClO₄)₂(OH)₂(C₁₀H₈N₂)₂], the Cu^II ion is coordinated in the form of a Jahn–Teller distorted octahedron by two bi­pyridine N atoms, two perchlorate O atoms and two hydroxide O atoms, and displays a distorted octa­hedral geometry. The mol­ecule belongs to the symmetry point group C_2h. The Cu^II ion is located on a twofold rotation axis and the hydroxide and perchlorate ligands are located on a mirror plane. Within the dinuclear mol­ecule, the Cu...Cu separation is 2.8614 (7) Å. The crystal structure exhibits O—H...O, C—H...O and π–π [centroid–centroid distance = 3.5374 (13) Å] inter­actions.

1H-Benzotriazole–4-hy­droxy­benzoic acid (1/1)

The asymmetric unit of the title compound, C₆H₅N₃·C₇H₆O₃, comprises independent benzotriazole and 4-hydroxybenzoic acid molecules. The dihedral angle between the benzene ring and the benzotriazole ring system is 15.18 (7)°. The mean plane of the carb­oxyl group is twisted at an angle of 18.55 (1)° with respect to the benzene ring. The crystal structure is stabilized by weak inter­molecular N—H...N, O—H...N, O—H...O and C—H...O inter­actions, forming a three-dimensional network.

4-Nitro­anilinium 3-carb­oxy-4-hy­droxy­benzene­sulfonate monohydrate

In the title hydrated salt, C₆H₇N₂O₂⁺·C₇H₅O₆S⁻·H₂O, the benzene ring of the cation makes a dihedral angle of 1.32 (19)° with the attached nitro group. In the anion, an intra­molecular O—H...O hydrogen bond with an S(6) ring motif is formed between the carb­oxyl and hy­droxy groups; the dihedral angle between the carb­oxyl group and the benzene ring is 8.76 (8)°. The crystal structure exhibits inter­molecular N—H...O, O—H...O, C—H...O, and π–π [centroid–centroid distances = 3.6634 (9) and 3.7426 (9) Å] inter­actions to form a three-dimensional network.

Uronium 3-carb­oxy-4-hy­droxy­benzene­sulfonate

In the title compound, CH₅N₂O⁺·C₇H₅O₆S⁻, the dihedral angle between the benzene ring and the mean plane of the uronium cation is 76.02 (8)°. The carboxyl group in the anion is twisted by 1.47 (9)° from the benzene ring. In the crystal, the cation is linked to the anion by weak O—H...O and N—H...O hydrogen bonds and π–π inter­actions [centroid–centroid distance = 3.8859 (8) Å], forming a three-dimensional network.