The structures of four alkali metal salt forms of sulfadiazine and two organic salt forms of sulfadiazine are described and the bonding modes of the sulfadiazine ligand are discussed.

The structures of five gold complexes involving piperidine or pyrrolidine, either as neutral ligands or protonated counter-cations, are presented.

New structures of the N-terminal 43 kDa fragment of the E. coli DNA gyrase B subunit reveal two discrete monovalent cation-binding sites that could have functional roles.

The asymmetric unit of the title salt, C₁₂H₃₂N₄²⁺·2C₁₈HBF₁₅O⁻·2.5C₆H₆, which crystallizes in the triclinic space group P, comprises two half [C₁₂H₃₂N₄]²⁺ dications, two [C₁₈HBF₁₅O]⁻ anions, and 2.5 mol­ecules of benzene as solvate.

The structures of two semiconducting thio­stannates (R₂Sn₃S₇, R is an organic cation) were investigated in detail using single-crystal X-ray diffraction, solid-state NMR spectroscopy and electron microscopy. The atomic level structures of the compounds are discussed in relation to their different light absorption properties.

The complex [tris­(pyridin-2-ylmeth­yl)amine]­copper(II) bromide adopts a trigonal–bipyramidal coordination geometry about the Cu^II ion. The outer sphere bromine counter-ions are severely disordered.

In the title compound, the coordination of the two tridentate ligands bis­(pyridin-2-yl)methanamine to Fe^II results in a strongly distorted octa­hedral [FeN₆] coordination polyhedron, with acute N—Fe—N bite angles in the five-membered metalacycles.

The asymmetric unit of the title compound consists of two independent ion pairs of 4-(di­methyl­amino)­pyridin-1-ium quinolin-8-ol-5-sulfonate (HDMAP⁺·HqSA⁻) and neutral N,N-di­methyl­pyridin-4-amine (DMAP), forming a 1:1:1 cation:anion:neutral mol­ecule co-crystal. The compound has a layered structure, including cation layers of HDMAP⁺ with DMAP and anion layers of HqSA⁻ in the crystal. The cation and anion layers are linked by inter­molecular C—HO hydrogen bonds and C—Hπ inter­actions.

The new copper(II) complex [CuLCl₂]₂, where L is a product of Schiff base condensation between methyl­amine and 2-pyridine­carbaldehyde, is built of discrete centrosymmetric dimers.

The crystal structure of bis­{bis­(azido-κN)bis­[bis­(pyridin-2-yl-κN)amine]­cobalt(III)} sulfate dihydrate is comprised of discrete [Co(dpa)₂(N₃)₂]⁺ cations, SO₄²⁻ anions and solvent water mol­ecules in a 2:1:2 ratio; extensive hydrogen-bonding inter­actions link the species into a three-dimensional supra­molecular framework.