In the title complex, poly[copper(II)-di-μ-5-carboxy-1H-imidazole-4-carboxyl­ato], [Cu(C₅H₃N₂O₄)₂]_n or [Cu(H₂Imda)₂]_n, each imidazole moiety is bonded to the Cu atom via O and N atoms to give a square-planar coordination [Cu—O = 2.014 (2) and 2.016 (2) Å, and Cu—N = 1.982 (3) and 1.992 (2) Å]. The distorted square-pyramidal geometry at the Cu atom results from coordination to an adjacent O atom [Cu—O = 2.305 (2) Å], which generates zigzag chains. There is a sixth, weaker, octahedral coordination to the Cu atom from an inversion-related O atom [Cu—O = 3.090 (2) Å], which links the chains into sheets in the (100) plane. Imidazole moieties in the sheets are linked in the [100] direction by pairs of N—HO and C—HO hydrogen bonds, thus generating a three-dimensional network.

The solid solution in the system Zr–Mo–W–O with composition ZrW_1.75Mo_0.25O₈ (zirconium tungsten molybdenum octa­oxide) was prepared by solid-state reactions as a polycrystalline material. Its structure has cubic symmetry (space group P2₁3) at room temperature. The structure contains a network of corner-sharing ZrO₆ octa­hedra (.3. symmetry) and MO₄ (M = W, Mo) tetra­hedra (.3. symmetry). Along the main threefold axis of the cubic unit cell, the MO₄ tetra­hedra are arranged in pairs forming M₂O₈ units in which the M1O₄ tetra­hedra have larger distortions in terms of bond distances and angles than the M2O₄ tetra­hedra. These units are disordered over two possible orientations, with the M—O_terminal vectors pointing to the [111] or [] directions. The reversal of the orientations of the M₂O₈ units results from the concerted flips of these units. The time-averaged proportions of flipped and unflipped M₂O₈ units were determined and the fraction of unflipped M₂O₈ units is about 0.95. The order degree of the M₂O₈ unit orientation is about 0.9. During the reversal process, the M-atom site has a migration about 0.93 Å, one of the O-atom sites has a 0.25 Å migration distance, whereas two other O-atom sites migrate marginally (≃ 0.08 Å). The results prove the constraint strategy to be a reasonable approach based on the ratcheting mechanism.

The title compound, [Zn(C₈H₄N₄O₂)]_n, is a coordination polymer prepared by the hydro­thermal reaction of zinc chloride and 3-(1H-tetrazol-5-yl)­benzoic acid. The zinc cation is tetrahedrally coordinated by two N atoms and two O atoms from four ligands, resulting in a three-dimensional framework encapsulating one-dimensional channels.

The reaction of terephthalo­nitrile and sodium azide catalyzed by manganese chloride tetrahydrate converts one nitrile group to tetrazole and leaves the other nitrile group unchanged. The Mn^II atom in the title compound, [Mn(H₂O)₆](C₈H₄N₅)₂, is coordinated by six water mol­ecules and lies on a position of 2/m crystallographic symmetry. The plane of the tetrazolate anion is perpendicular to a crystallographic mirror plane.

The hydro­thermal reaction of manganese chloride tetrahydrate and 5,5'-(1,4-phenyl­ene)­bis(1H-tetrazole) gave the title compound, [Mn(H₂O)₆](C₈H₄N₈). In the mol­ecule, the Mn^II atom is octahedrally coordinated by six water mol­ecules and is located on an inversion center. The centrosymmetric tetrazolate anion remains unligated and links to water via hydrogen bonds.

The crystal structure of polymeric di­aqua-8-hydroxy­quinolinyl-5-sulfonatozinc(II) consists of a centrosymmetric (C₉H₅NO₄S)₂(H₂O)₂Zn₂ entity which is linked into a network structure by intermolecular sulfonyl bridges. The network is further consolidated by hydrogen bonds involving the coordinated water mol­ecules.

In the title compound, [Cd(C₈H₃O₇S)(C₆H₁₃N₂)(H₂O)]_n, the Cd atom is coordinated by one O atom of a carboxyl­ate group of a 5-sulfatoisophthalato ligand, two O atoms of the carboxyl­ate group group of an adjacent symmetry-related 5-sulfo­isophthalato entity, one O atom of the sulfonyl group of yet another adjacent 5-sulfatooisophthalato entity, a water mol­ecule and the N atom of the 1-aza-4-azoniabi­cyclo­[2.2.2]­octane cation in a six-coordinate octahedral geometry. Thus, the mode of coordination of the 5-sulfatoisophthalato ligand leads to the formation of a linear ribbon motif; adjacent ribbons are linked by hydrogen-bonding interactions, giving rise to a three-dimensional network structure.

The Cu atom in [Cu(C₁₀H₈N₂)₂(H₂O)₄](C₁₂H₆O₄)·3H₂O exists in a trans-N₂O₄ octahedral coordination polyhedron that is formed by the N atoms of two 4,4'-bi­pyridine heterocycles and the O atoms of four water mol­ecules. The carboxyl­ate groups of the centrosymmetric anions interact indirectly with the Cu atoms through the coordinated water mol­ecules. The cations and anions are linked by hydrogen bonds into a network motif. The Cu atom lies at a site of 2 symmetry.

The title crystal structure, {Na₂[Cd₂(C₁₂H₁₀N₂)(C₈H₃O₇S)₂]·6H₂O}_n, contains pentagonal–bipyramidal Cd atoms and octahedral Na atoms. The Cd atom is chelated by two carboxyl groups of adjacent 5-sulfoisophthalate(3−) trianions, and it is also coordinated by the pyridyl group of the centrosymmetric heterocycle, the coordinating atoms comprising the pentagonal plane around the metal atom. In the network structure, the Na atoms occupy the voids in the network such that they exist in a six-coordinate geometry.

The title compound, [Cd(C₈H₇N₄O₂)₂]_n, crystallizes in the centrosymmetric triclinic space group P with an asymmetric unit consisting of a bivalent Cd^II atom and two 2-(2,2'-bi-1H-imidazol-1-yl)acetate (BDAC^-) anions. Two inversion-related BDAC^- ligands are oppositely arranged and bind two Cd^II ions to form a [Cd₂(BDAC)₂] rhomboid subunit which is bridged by another BDAC^- ligand to form an infinite ladder along the a direction containing parallelogram grids. The three-dimensional supra­molecular architecture is formed by hydrogen bonds and C-H and - inter­actions.

In the title mixed-ligand metal-organic polymeric complex [Cd(C₁₄H₈O₆S)(C₁₆H₁₆N₂)(H₂O)]_n, the asymmetric unit con­tains a crystallographically unique Cd^II atom, one doubly deprotonated 4,4'-sulfonyl­dibenzoic acid ligand (H₂SDBA), one 3,4,7,8-tetra­methyl-1,10-phenanthroline (TMPHEN) mol­ecule and one water mol­ecule. Each Cd^II centre is coordinated by two N atoms from the chelating TMPHEN ligand, three O atoms from monodentate carboxyl­ate groups of three different SDBA^2- ligands and one O atom from a coordinated water mol­ecule, giving a distorted CdN₂O₄ octa­hedral geom­etry. Single-crystal X-ray diffraction analysis reveals that the compound is a one-dimensional double-chain polymer con­taining 28-membered rings based on Cd₂O₂ clusters, with a CdCd separation of 3.6889 (4) Å. These chains are linked by O-HO and C-HO hydrogen bonds to form a three-dimensional supra­molecular framework. The framework is reinforced by - and C-O inter­actions.