catena‐Poly[bis[tetraaquacobalt(II)‐μ‐4,4′‐bipyridine‐κ2N:N′] benzene‐1,2,4,5‐tetracarboxylate(4−) dihydrate]

The title compound, [Co(C₁₀H₈N₂)(H₂O)₄]₂(C₁₀H₂O₈)·2H₂O, consists of two crystallographically independent Co^II atoms linked by 4,4′‐bi­pyridine ligands into one‐dimensional chains, which are further connected into a three‐dimensional framework linked by [C₆H₂(COO)₄]^4? anions and water mol­ecules, achieved through complex hydrogen bonding.     

Poly[diaquabis(μ‐4,4′‐bipyridine‐κ2N:N′)bis(ethane‐1,2‐diol)di‐μ‐sulfato‐dicopper(II)]

The title compound, [Cu₂(SO₄)₂(C₁₀H₈N₂)₂(C₂H₆O₂)₂(H₂O)₂]_n, contains two crystallographically unique Cu^II centres, each lying on a twofold axis and having a slightly distorted octahedral environment. One Cu^II centre is coordinated by two bridging 4,4′‐bipyridine (4,4′‐bipy) ligands, two sulfate anions and two aqua ligands. The second is surrounded by two 4,4′‐bipy N atoms and four O atoms, two from bridging sulfate anions and two from ethane‐1,2‐diol ligands. The sulfate anion bridges adjacent Cu^II centres, leading to the formation of linear ...Cu1–Cu2–Cu1–Cu2... chains. Adjacent chains are further bridged by 4,4′‐bipy ligands, which are also located on the twofold axis, resulting in a two‐dimensional layered polymer. In the crystal structure, extensive O—H...O hydrogen‐bonding interactions between water molecules, ethane‐1,2‐diol molecules and sulfate anions lead to the formation of a three‐dimensional supramolecular network structure.     

Tetraaqua(4,4′‐dimethyl‐2,2′‐bipyridine‐κ2N,N′)nickel(II) sulfate monohydrate: a simple molecule with an extremely complex hydrogen‐bonding scheme

The title ionic compound, [Ni(C₁₂H₁₂N₂)(H₂O)₄]SO₄·H₂O, is composed of an Ni^II cation coordinated by a chelating 4,4′‐dimethyl‐2,2′‐bipyridine ligand via its two N atoms [mean Ni—N = 2.056 (2) Å] and by four aqua ligands [mean Ni—O = 2.073 (9) Å], the net charge being balanced by an external sulfate anion. The whole structure is stabilized by a solvent water molecule. Even though the individual constituents are rather featureless, they generate an extremely complex supramolecular structure consisting of a central hydrogen‐bonded two‐dimensional hydrophilic nucleus made up of complex cations, sulfate anions and coordinated and solvent water molecules, with pendant hydrophobic 4,4′‐dimethyl‐2,2′‐bipyridine ligands which interact laterally with their neighbours viaπ–π interactions. The structure is compared with closely related analogues in the literature.     

Triaqua(2,2′‐bipyridine‐κ2N,N′)(nitrato‐κO)manganese(II) nitrate

The crystal structure of the title compound, [Mn(NO₃)(C₁₀H₈N₂)(H₂O)₃]NO₃, contains a monomeric [Mn(NO₃)(bpy)(H₂O)₃]⁺ cation (bpy is 2,2′‐bi­pyridine) and a nitrate anion. The Mn^II ion is coordinated by one chelating bpy [Mn—N 2.241 (3) and 2.259 (3) Å], three water mol­ecules [Mn—O 2.120 (3)–2.188 (3) Å] and a nitrate ligand [Mn—O 2.228 (2) Å] in a distorted octahedral geometry. There are O?H—O hydrogen‐bonding interactions between the ligated water mol­ecules and the ligated and unligated nitrate anions, resulting in double columns of stacked cations and anions.     

A new coordination mode of 6‐methylnicotinic acid in trans‐tetraaquabis(6‐methylpyridine‐3‐carboxylato‐κO)cobalt(II) tetrahydrate

The title compound, [Co(C₇H₆NO₂)₂(H₂O)₄]·4H₂O, contains a Co^II ion lying on a crystallographic inversion centre. The Co^II ion is octahedrally coordinated by two 6‐methylpyridine‐3‐carboxylate ligands in axial positions [Co—O = 2.0621 (9) Å] and by four water molecules in the equatorial plane [Co—O = 2.1169 (9) and 2.1223 (11) Å]. There are also four uncoordinated water molecules. The 6‐methylpyridine‐3‐carboxylate ligands are bound to the Co^II ion in a monodentate manner through a carboxylate O atom. There is one strong intramolecular O—H...O hydrogen bond, and six strong intermolecular hydrogen bonds of type O—H...O and one of type O—H...N in the packing, resulting in a complex three‐dimensional supramolecular structure.     

Tetra­aqua(2,2′‐bi­pyridine)­nickel(II) terephthalate

The reaction of nickel(II) nitrate with terephthalic acid and 2,2′‐bi­pyridine in di­methyl­form­amide solution gives the title complex, [Ni(C₁₀H₈N₂)(H₂O)₄](C₈H₄O₄). The Ni^II ion is octahedrally coordinated to one 2,2′‐bi­pyridine and four water mol­ecules and does not coordinate to the terephthalate anion. Hydro­gen bonds between the terephthalate anions and the [Ni(2,2′‐bipy)(H₂O)₄]²⁺ cations produce a two‐dimensional hydrogen‐bonding architecture with double sheets.     

Poly[[trans‐diaquabis(μ2‐biphenyl‐2,2′‐dicarboxylato)bis(μ2‐4,4′‐bipyridine)dicobalt(II)] biphenyl‐2,2′‐dicarboxylic acid disolvate]

In the title compound, {[Co₂(C₁₄H₈O₄)₂(C₁₀H₈N₂)₂(H₂O)₂]·2C₁₄H₁₀O₄}_n, each Co^II ion is six‐coordinate in a slightly distorted octahedral geometry. Both Co^II ions are located on twofold axes. One is surrounded by two O atoms from two biphenyl‐2,2′‐dicarboxylate (dpa) dianions, two N atoms from two 4,4′‐bipyridine (bpy) ligands and two water molecules, while the second is surrounded by four O atoms from two dpa dianions and two N atoms from two bpy ligands. The coordinated dpa dianion functions as a κ³‐bridge between the two Co^II ions. One carboxylate group of a dpa dianion bridges two adjacent Co^II ions, and one O atom of the other carboxylate group also chelates to a Co^II ion. The Co^II ions are bridged by dpa dianions and bpy ligands to form a chiral sheet. There are several strong intermolecular hydrogen bonds between the H₂dpa solvent molecule and the chiral sheet, which result in a sandwich structure.     

Bis{tris[(1H‐benzimidazol‐3‐ium‐2‐yl)methyl]amine} tetraaquaocta‐μ2‐chlorido‐octachloridopentacadmate(II) monohydrate

The title compound, (C₂₄H₂₄N₇)₂[Cd₅Cl₁₆(H₂O)₄]·H₂O, contains a [Cd₅Cl₁₆(H₂O)₄]⁶⁻ anion, two triply protonated tris[(1H‐benzimidazol‐3‐ium‐2‐yl)methyl]amine cations and one solvent water molecule. The structure of the anion is a novel chloride‐bridged pentanuclear cluster. The five unique Cd^II centres have quite different coordination environments. Two of the central hexacoordinated Cd^II cations have a CdOCl₅ chromophore, in which each Cd^II cation is ligated by four bridging chloride ligands, one terminal chloride ligand and one water molecule, adopting a distorted octahedral environment. The third central Cd^II cation is octahedrally coordinated by four bridging chloride ligands and two water molecules. Finally, the two terminal Cd^II cations are pentacoordinated by two bridging and three terminal chloride ligands and adopt a trigonal–bipyramidal geometry. A three‐dimensional supramolecular network is formed through intra‐ and intermolecular O—H...O, O—H...Cl, N—H...Cl and N—H...O hydrogen bonds and π–π interactions between the cations and anions.<!?tpb=20.6pt>     

Poly[(μ4‐biphenyl‐3,3′,4,4′‐tetracarboxylato)bis[μ2‐1,4‐bis(imidazol‐1‐ylmethyl)benzene]dicobalt(II)]

The asymmetric unit of the title two‐dimensional coordination polymer, [Co₂(C₁₆H₆O₈)(C₁₄H₁₄N₄)₂]_n, contains one Co²⁺ ion, half of a biphenyl‐3,3′,4,4′‐tetracarboxylate (bptc) anion lying about an inversion centre and one 1,4‐bis(imidazol‐1‐ylmethyl)benzene (bix) ligand. The Co^II atom is coordinated by three carboxylate O atoms from two different bptc ligands and two N atoms from two bix ligands constructing a distorted square pyramid. Each Co²⁺ ion is interlinked by two bptc anions, while each bptc anion coordinates to four Co atoms as a hexadentate ligand so that four Co^II atoms and four bptc anions afford a larger 38‐membered ring. These inorganic rings are further extended into a two‐dimensional undulated network in the (10) plane. Two Co^II atoms in adjacent 38‐membered rings are joined together by pairs of bix ligands forming a 26‐membered [Co₂(bix)₂] ring that is penetrated by a bptc anion; these components share a common inversion centre.     

Helical catena‐poly[[tris(1H‐benzimidazole‐κN3)cobalt(II)]‐μ‐maleato‐κ3O,O′:O′′]

The crystal structure of the title compound, [Co(C₄H₂O₄)(C₇H₆N₂)₃]_n, consists of polymeric chains of the Co^II complex. Two maleate dianions and three benz­imidazole ligands coordinate to the Co^II atom with a distorted octahedral geometry. The maleate dianions bridge neighbouring Co^II atoms via both terminal carboxylic acid groups, one of which is monodentate and the other bidentate, to form a helical structure of alternating maleate dianions and Co^II atoms, with a pitch height of 9.2667 (17) Å. The absolute structure has been determined, and the crystal contains only right‐handed helices. Intrahelical N—H⋯O hydrogen bonds stabilize the helical structure, while interhelical N—H⋯O hydrogen bonds link neighbouring helices to form the supramolecular structure.     

A novel two‐dimensional cobalt(II) complex composed of one‐dimensional twisted pair‐like chains: poly[[tetraaquabis(μ3‐pyridine‐2,5‐dicarboxylato‐κ4N,O2:O5:O5′)dicobalt(II)] dihydrate]

A novel neutral polymer, {[Co₂(C₇H₃NO₄)₂(H₂O)₄]·2H₂O}_n, was hydrothermally synthesized using pyridine‐2,5‐dicarboxylate (2,5‐PDC²⁻) as the organic linker. It features a two‐dimensional layer structure constructed from one‐dimensional {[Co(2,5‐PDC)₂]²⁻}_n chains interlinked by [Co(H₂O)₄]⁺ units. The two Co^II cations occupy special positions, sitting on inversion centres. Each 2,5‐PDC²⁻ anion chelates to one Co^II cation via the pyridine N atom and an O atom of the adjacent carboxylate group, and links to two other Co^II cations in a bridging mode via the O atoms of the other carboxylate group. In this way, the 2,5‐PDC²⁻ ligand connects three neighbouring Co^II centres to form a two‐dimensional network. The two‐dimensional undulating layers are linked by extensive hydrogen bonds to form a three‐dimensional supramolecular structure, with the uncoordinated solvent molecules occupying the interlamellar region.     

Tris­[(R)‐lact­amide‐κ2O,O′]­zinc(II) tetra­bromo­zincate

The title compound, tris­[(R)‐2‐hydroxy­propan­amide‐κ²O,O′]­zinc(II) tetra­bromo­zincate, [Zn(C₃H₇NO₂)₃][ZnBr₄], contains one monomeric six‐coordinate zinc complex cation and one tetrahedral [ZnBr₄]²⁻ anion. Both Zn^II atoms lie on threefold axes. Coordination in the cation occurs via the amide and hydroxy O atoms [Zn—O = 2.074 (5) and 2.073 (6) Å] and has a distorted octahedral geometry, with cis‐O—Zn—O angles in the range 76.2 (2)–109.2 (2)°. In the crystal structure, the cations and anions are linked by N—H⋯Br and O—H⋯O hydrogen bonds, generating a three‐dimensional network.     

Bis(di‐2‐pyridylamine‐κ2N2,N2′)(nitrato‐κ2O,O′)nickel(II) nitrate

<!?tpct=26.8pt>In the ionic title compound, [Ni(NO₃)(C₁₀H₉N₃)₂]NO₃, the central Ni^II atom exhibits cis‐NiN₄O₂ octahedral coordination with three chelating ligands, viz. one nitrate anion and two di‐2‐pyridylamine (dpya) molecules. A second nitrate group acts as a counter‐ion. The complex cations and the nitrate anions are also linked by N—H...O hydrogen bonds. The compound was prepared in two different reproducible ways: direct synthesis from Ni(NO₃)₂ and dpya yielded systematically twinned crystals (the twinning law is discussed), while single crystals were obtained unexpectedly from the Ni(NO₃)₂/dpya/maleic acid/NaOH system.     

A simple hydrated salt with a complex hydrogen‐bonding network: tetrakis(5‐amino‐3‐carboxy‐4H‐1,2,4‐triazol‐1‐ium) hexachloridocadmate(II) tetrahydrate

In the title cadmium chloride salt, (C₃H₅N₄O₂)₄[CdCl₆]·4H₂O, the asymmetric unit comprises two N‐protonated 5‐amino‐3‐carboxy‐4H‐1,2,4‐triazol‐1‐ium cations, half a [CdCl₆]⁴⁻ anion and two molecules of water. The Cd²⁺ cation is located on a centre of inversion and is coordinated by six chloride anions, forming a distorted octahedron. In the crystal structure, alternating layers of cations and anions are arranged along the [101] direction, forming a three‐dimensional supramolecular network via a combination of hydrogen‐bonding and aromatic stacking interactions.     

Synthesis,crystal structure and magnetic properties of a two‐dimensional cyanide‐based heterometallic coordination polymer with cationic piperazinium ligands: poly[aquatetra‐μ2‐cyanido‐κ8C:N‐dicyanido‐κ2C‐(piperazinium‐κN4)cobalt(III)copper(II)]

Cyanide as a bridge can be used to construct homo‐ and heterometallic complexes with intriguing structures and interesting magnetic properties. These ligands can generate diverse structures, including clusters, one‐dimensional chains, two‐dimensional layers and three‐dimensional frameworks. The title cyanide‐bridged Cu^II–Co^III heterometallic compound, [Cu^IICo^III(CN)₆(C₄H₁₁N₂)(H₂O)]_n, has been synthesized and characterized by single‐crystal X‐ray diffraction analysis, magnetic measurement, thermal study, vibrational spectroscopy (FT–IR) and scanning electron microscopy/energy‐dispersive X‐ray spectroscopy (SEM–EDS). The crystal structure analysis revealed that it has a two‐dimensional grid‐like structure built up of [Cu(Hpip)(H₂O)]³⁺ cations (Hpip is piperazinium) and [Co(CN)₆]³⁻ anions that are linked through bridging cyanide ligands. The overall three‐dimensional supramolecular network is expanded by a combination of interlayer O—H...N and N—H...O hydrogen bonds involving the coordinated water molecules and the N atoms of the nonbridging cyanide groups and monodentate cationic piperazinium ligands. A magnetic investigation shows that antiferromagnetic interactions exist in the title compound.     

New organic–inorganic frameworks incorporating iso‐ and heteropolymolybdate units and a 3,3′,5,5′‐tetramethyl‐4,4′‐bi‐1H‐pyrazole‐2,2′‐diium multiple hydrogen‐bond donor

Poly[bis(3,3′,5,5′‐tetramethyl‐4,4′‐bi‐1H‐pyrazole‐2,2′‐diium) γ‐octamolybdate(VI) dihydrate], {(C₁₀H₁₆N₄)₂[Mo₈O₂₆]·2H₂O}_n, (I), and bis(3,3′,5,5′‐tetramethyl‐4,4′‐bi‐1H‐pyrazole‐2,2′‐diium) α‐dodecamolybdo(VI)silicate tetrahydrate, (C₁₀H₁₆N₄)₂[SiMo₁₂O₄₀]·4H₂O, (II), display intense hydrogen bonding between the cationic pyrazolium species and the metal oxide anions. In (I), the asymmetric unit contains half a centrosymmetric γ‐type [Mo₈O₂₆]⁴⁻ anion, which produces a one‐dimensional polymeric chain by corner‐sharing, one cation and one water molecule. Three‐centre bonding with 3,3′,5,5′‐tetramethyl‐4,4′‐bi‐1H‐pyrazole‐2,2′‐diium, denoted [H₂Me₄bpz]²⁺ [N...O = 2.770 (4)–3.146 (4) Å], generates two‐dimensional layers that are further linked by hydrogen bonds involving water molecules [O...O = 2.902 (4) and 3.010 (4) Å]. In (II), each of the four independent [H₂Me₄bpz]²⁺ cations lies across a twofold axis. They link layers of [SiMo₁₂O₄₀]⁴⁻ anions into a three‐dimensional framework, and the preferred sites for pyrazolium/anion hydrogen bonding are the terminal oxide atoms [N...O = 2.866 (6)–2.999 (6) Å], while anion/aqua interactions occur preferentially viaμ₂‐O sites [O...O = 2.910 (6)–3.151 (6) Å].     

Poly[[aqua(4,4′‐diazenediyldibenzoato‐κ4O,O′:O′′,O′′′)cadmium(II)]: a twofold interpenetrated three‐dimensional coordination polymer of PtS topology

In the title coordination compound, [Cd(C₁₄H₈N₂O₄)(H₂O)]_n, the Cd^II cation and the coordinated water molecule lie on a twofold axis, whereas the ligand lies on an inversion center. The Cd^II center is five‐coordinated in a distorted square‐pyramidal geometry by four carboxylate O atoms from four different 4,4′‐diazenediyldibenzoate (ddb) anions and one water O atom. The three‐dimensional frameworks thus formed by the bridging ddb anions interpenetrate to generate a three‐dimensional PtS‐type network. Additionally, the coordination water molecule and the carboxylate O atom form a hydrogen‐bonding interaction, stabilizing the three‐dimensional framework structure.     

Bis[diaquabis(2,2‐bipyridine N,N′‐dioxide‐κ2O,O′)cobalt(II)] ξ‐octamolybdate dihydrate

The title organic–inorganic hybrid compound, [Co(C₁₀H₈N₂O₂)₂(H₂O)₂]₂[Mo₈O₂₆]·2H₂O, consists of [Co(bpdo)₂(H₂O)₂]²⁺ (bpdo is 2,2‐bipyridine N,N′‐dioxide) and ξ‐[Mo₈O₂₆]⁴⁻ groups in a 2:1 ratio, plus two water solvent molecules. The independent Co atom in the cation is coordinated by four O atoms from two bpdo ligands and two water molecules, in a distorted octahedral geometry. The counter‐anions, built up around a symmetry center, are linked by solvent water molecules through O—H...O hydrogen bonds to generate two‐dimensional layers, which are in turn linked by coordinated water molecules from the cationic units through further O—H...O hydrogen bonds, forming a three‐dimensional supramolecular structure.     

A mixed‐valence CuII/CuI anion–cation complex: bis­[μ‐5‐sulfosali­cylato(3–)]bis­[(di‐2‐pyridylamine)­copper(II)] bis­[bis­(di‐2‐pyridyl­amine)copper(I)] dihydrate

The title compound, [Cu(C₇H₃O₆S)₂(C₁₀H₉N₃)₂][Cu^I(C₁₀H₉N₃)₂]₂·2H₂O, consists of anionic Cu^II moieties, cationic Cu^I species and uncoordinated water mol­ecules. The anionic dimeric unit consists of one crystallographically independent fully deprotonated 5‐sulfosalicylate (2‐oxido‐5‐sulfonatobenzoate) anion, a di‐2‐pyridylamine group and a Cu^II atom. Each Cu^II atom is five‐coordinate within a square‐pyramidal geometry. The anion lies on a special position of site symmetry. In the cationic monomer, the Cu^I atom adopts tetra­hedral geometry. The cations and anions are connected by O—H·O and N—H·O hydrogen bonds.     

Di‐μ2‐sulfito‐κ8O,O′:O′,O′′‐bis[(2,4,6‐tri‐2‐pyrid­yl‐1,3,5‐triazine‐κ3N2,N1,N6)cadmium(II)] octa­hydrate

The title compound, [Cd₂(SO₃)₂(C₁₈H₁₂N₆)₂]·8H₂O, is a dimer built up around a symmetry center, where the sulfite anion displays a so far unreported coordination mode in metal‐organic complexes; the anion binds as a μ₂‐sulfite‐κ⁴O,O′:O′,O′′ ligand to two symmetry‐related seven‐coordinate Cd^II cations, binding through its three O atoms by way of two chelate bites with an O atom in common, which acts as a bridge. The cation coordination is completed by a 2,4,6‐tri‐2‐pyridyl‐1,3,5‐triazine ligand acting in its usual tridentate mode.