Two isomorphous ZnII/CoII complexes with tri‐tert‐butoxysilanethiol and histamine,and (4‐hydroxymethyl‐1H‐imidazole‐κN)bis(tri‐tert‐butoxysilanethiolato‐κ2O,S)zinc(II)

The complexes [2‐(1H‐imidazol‐4‐yl‐κN³)ethylamine‐κN]bis(tri‐tert‐butoxysilanethiolato‐κS)cobalt(II), [Co(C₁₂H₂₇O₃SSi)₂(C₅H₉N₃)], and [2‐(1H‐imidazol‐4‐yl‐κN³)ethylamine‐κN]bis(tri‐tert‐butoxysilanethiolato‐κS)zinc(II), [Zn(C₁₂H₂₇O₃SSi)₂(C₅H₉N₃)], are isomorphous. The central Zn^II/Co^II ions are surrounded by two S atoms from the tri‐tert‐butoxysilanethiolate ligand and by two N atoms from the chelating histamine ligand in a distorted tetrahedral geometry, with two intramolecular N—H...O hydrogen‐bonding interactions between the histamine NH₂ groups and tert‐butoxy O atoms. Molecules of the complexes are joined into dimers via two intermolecular bifurcated N—H...(S,O) hydrogen bonds. The Zn^II atom in [(1H‐imidazol‐4‐yl‐κN³)methanol]bis(tri‐tert‐butoxysilanethiolato‐κ²O,S)zinc(II), [Zn(C₁₂H₂₇O₃SSi)₂(C₄H₆N₂O)], is five‐coordinated by two O and two S atoms from the O,S‐chelating silanethiolate ligand and by one N atom from (1H‐imidazol‐4‐yl)methanol; the hydroxy group forms an intramolecular hydrogen bond with sulfur. Molecules of this complex pack as zigzag chains linked by N—H...O hydrogen bonds. These structures provide reference details for cysteine‐ and histidine‐ligated metal centers in proteins.     

A three‐dimensional supramolecular framework of silver(I), 2‐phenylquinoline‐4‐carboxylate and 4,4′‐bipyridine

A novel supramolecular framework, catena‐poly[[[aqua(2‐phenylquinoline‐4‐carboxylato‐κO)silver(I)]‐μ‐4,4′‐bipyridine‐κ²N:N′] dihydrate], {[Ag(C₁₆H₁₀NO₂)(C₁₀H₈N₂)(H₂O)]·2H₂O}_n, has been synthesized and structurally characterized. The Ag^I centres are four‐coordinated and bridged by 4,4′‐bipyridine (4,4′‐bipy) ligands to form a one‐dimensional Ag–bipy chain. The Ag–bipy chains are further linked together by intermolecular O—H...O and O—H...N hydrogen‐bonding interactions between adjacent chains, resulting in a three‐dimensional framework.     

Two new cadmium(II) coordination polymers based on bis(1,2,4‐triazol‐1‐yl)alkane ligands and pyrazine‐2,3‐dicarboxylic acid

Assemblies of pyrazine‐2,3‐dicarboxylic acid and Cd^II in the presence of bis(1,2,4‐triazol‐1‐yl)butane or bis(1,2,4‐triazol‐1‐yl)ethane under ambient conditions yielded two new coordination polymers, namely poly[[tetraaqua[μ₂‐1,4‐bis(1,2,4‐triazol‐1‐yl)butane‐κ²N⁴:N^4′]bis(μ₂‐pyrazine‐2,3‐dicarboxylato‐κ³N¹,O²:O³)dicadmium(II)] dihydrate], {[Cd₂(C₆H₂N₂O₄)₂(C₈H₁₂N₆)(H₂O)₄]·2H₂O}_n, (I), and poly[[diaqua[μ₂‐1,2‐bis(1,2,4‐triazol‐1‐yl)ethane‐κ²N⁴:N^4′]bis(μ₃‐pyrazine‐2,3‐dicarboxylato‐κ⁴N¹,O²:O³:O^3′)dicadmium(II)] dihydrate], {[Cd₂(C₆H₂N₂O₄)₂(C₆H₈N₆)(H₂O)₂]·2H₂O}_n, (II). Complex (I) displays an interesting two‐dimensional wave‐like structure and forms a distinct extended three‐dimensional supramolecular structure with the help of O—H...N and O—H...O hydrogen bonds. Complex (II) has a three‐dimensional framework structure in which hydrogen bonds of the O—H...N and O—H...O types are found.     

CdII and CoII coordination polymers constructed from benzene‐1,4‐dicarboxylic acid and 2‐(pyridin‐3‐yl)‐1H‐benzimidazole ligands

In poly[aqua(μ₃‐benzene‐1,4‐dicarboxylato‐κ⁵O¹,O^1′:O¹:O⁴,O^4′)[2‐(pyridin‐3‐yl‐κN)‐1H‐benzimidazole]cadmium(II)], [Cd(C₈H₄O₄)(C₁₂H₉N₃)(H₂O)]_n, (I), each Cd^II ion is seven‐coordinated by the pyridine N atom from a 2‐(pyridin‐3‐yl)benzimidazole (3‐PyBIm) ligand, five O atoms from three benzene‐1,4‐dicarboxylate (1,4‐bdc) ligands and one O atom from a coordinated water molecule. The complex forms an extended two‐dimensional carboxylate layer structure, which is further extended into a three‐dimensional network by hydrogen‐bonding interactions. In catena‐poly[[diaquabis[2‐(pyridin‐3‐yl‐κN)‐1H‐benzimidazole]cobalt(II)]‐μ₂‐benzene‐1,4‐dicarboxylato‐κ²O¹:O⁴], [Co(C₈H₄O₄)(C₁₂H₉N₃)₂(H₂O)₂]_n, (II), each Co^II ion is six‐coordinated by two pyridine N atoms from two 3‐PyBIm ligands, two O atoms from two 1,4‐bdc ligands and two O atoms from two coordinated water molecules. The complex forms a one‐dimensional chain‐like coordination polymer and is further assembled by hydrogen‐bonding interactions to form a three‐dimensional network.     

Two new CoII coordination polymers with multifunctional 5‐amino‐2,4,6‐tribromoisophthalic acid and flexible isomeric bis(imidazole) ligands: preparation,crystal structure and characterization

Two new Co^II coordination polymers (CPs), namely, catena‐poly[[[(5‐amino‐2,4,6‐tribromobenzene‐1,3‐dicarboxylato‐κO)aquacobalt(II)]‐bis[μ‐1,3‐bis(imidazol‐1‐ylmethyl)benzene‐κ²N:N′]] 4.75‐hydrate], {[Co(C₈H₂Br₃NO₄)(C₁₄H₁₄N₄)₂(H₂O)]·4.75H₂O}_n, (1), and poly[(μ‐5‐amino‐2,4,6‐tribromobenzene‐1,3‐dicarboxylato‐κ²O¹:O³)[μ‐1,2‐bis(imidazol‐1‐ylmethyl)benzene‐κ²N:N′]cobalt(II)], [Co(C₈H₂Br₃NO₄)(C₁₄H₁₄N₄)]_n, (2), have been synthesized successfully by the assembly of multifunctional 5‐amino‐2,4,6‐tribromoisophthalic acid (H₂ATBIP) and Co^II ions in the presence of the flexible isomeric bis(imidazole) ligands 1,3‐bis(imidazol‐1‐ylmethyl)benzene (mbix) and 1,2‐bis(imidazol‐1‐ylmethyl)benzene (obix). The isomeric mbix and obix ligands have a big influence on the structures of CPs (1) and (2). CP (1) is composed of chains of nanometre‐sized elliptical rings, in which the Co^II atom exhibits a distorted octahedral coordination geometry and ATBIP²⁻ acts as a monodentate ligand. Two adjacent chains are interlinked by π–π stacking interactions and hydrogen bonds, resulting in a supramolecular double chain. Hydrogen‐bonded R₈⁶(16) rings extend adjacent supramolecular double chains into a two‐dimensional supramolecular layer. Halogen bonding and a hydrogen‐bonded R₄²(8) ring further link the two‐dimensional supramolecular layers, leading to the formation of a three‐dimensional supramolecular network. The Co^II ion in CP (2) is tetracoordinated, exhibiting a distorted tetrahedral configuration. The ATBIP²⁻ ligand exhibits a bis(monodentate) coordination bridging mode, linking adjacent Co^II ions into zigzag chains, which are further bridged by the auxiliary bridging obix ligand, resulting in a two‐dimensional (4,4) topological network. Interlayer hydrogen and halogen–halogen bonding further extend the two‐dimensional layers into a three‐dimensional supramolecular network. A detailed analysis of the solid‐state UV–Vis–NIR diffuse‐reflectance spectra of (1) and (2) indicates that a wide optical band gap exists in both (1) and (2). CP (1) exhibits an irreversible dehydration–rehydration behaviour.     

Two‐dimensional ZnII and one‐dimensional CoII coordination polymers based on benzene‐1,4‐dicarboxylate and pyridine ligands

Coordination polymers constructed from metal ions and organic ligands have attracted considerable attention owing to their diverse structural topologies and potential applications. Ligands containing carboxylate groups are among the most extensively studied because of their versatile coordination modes. Reactions of benzene‐1,4‐dicarboxylic acid (H₂BDC) and pyridine (py) with Zn^II or Co^II yielded two new coordination polymers, namely, poly[(μ₄‐benzene‐1,4‐dicarboxylato‐κ⁴O:O′:O′′:O′′′)(pyridine‐κN)zinc(II)], [Zn(C₈H₄O₂)(C₅H₅N)]_n, (I), and catena‐poly[aqua(μ₃‐benzene‐1,4‐dicarboxylato‐κ³O:O′:O′′)bis(pyridine‐κN)cobalt(II)], [Co(C₈H₄O₂)(C₅H₅N)₂(H₂O)]_n, (II). In compound (I), the Zn^II cation is five‐coordinated by four carboxylate O atoms from four BDC²⁻ ligands and one pyridine N atom in a distorted square‐pyramidal coordination geometry. Four carboxylate groups bridge two Zn^II ions to form centrosymmetric paddle‐wheel‐like Zn₂(μ₂‐COO)₄ units, which are linked by the benzene rings of the BDC²⁻ ligands to generate a two‐dimensional layered structure. The two‐dimensional layer is extended into a three‐dimensional supramolecular structure with the help of π–π stacking interactions between the aromatic rings. Compound (II) has a one‐dimensional double‐chain structure based on Co₂(μ₂‐COO)₂ units. The Co^II cations are bridged by BDC²⁻ ligands and are octahedrally coordinated by three carboxylate O atoms from three BDC²⁻ ligands, one water O atom and two pyridine N atoms. Interchain O—H…O hydrogen‐bonding interactions link these chains to form a three‐dimensional supramolecular architecture.     

Syntheses,structures and characterization of isomorphous CoII and NiII coordination polymers based on 2‐[(1H‐imidazol‐1‐yl)methyl]‐6‐methyl‐1H‐benzimidazole and benzene‐1,4‐dicarboxylate

Careful choice of the organic ligands is one of the most important parameters in the rational design and synthesis of coordination polymers. Aromatic polycarboxylates have been widely used in the preparation of metal–organic polymers since they can utilize various coordination modes to form diverse structures and can act as hydrogen‐bond acceptors and donors in the assembly of supramolecular structures. Nitrogen‐heterocyclic organic compounds have also been used extensively as ligands for the construction of polymers with interesting structures. In the polymers catena‐poly[[[diaquabis{2‐[(1H‐imidazol‐1‐yl)methyl]‐6‐methyl‐1H‐benzimidazole‐κN ³}cobalt(II)]‐μ₂‐benzene‐1,4‐dicarboxylato‐κ²O ¹:O ⁴] dihydrate], {[Co(C₈H₄O₄)(C₁₂H₁₁N₄)₂(H₂O)₂]·2H₂O}_n , (I), and catena‐poly[[[diaquabis{2‐[(1H‐imidazol‐1‐yl)methyl]‐6‐methyl‐1H‐benzimidazole‐κN ³}nickel(II)]‐μ₂‐benzene‐1,4‐dicarboxylato‐κ²O ¹:O ⁴] dihydrate], {[Ni(C₈H₄O₄)(C₁₂H₁₁N₄)₂(H₂O)₂]·2H₂O}_n , (II), the Co^II or Ni^II ion lies on an inversion centre and exhibits a slightly distorted octahedral coordination geometry, coordinated by two N atoms from two imidazole rings and four O atoms from two monodentate carboxylate groups and two water molecules. The dicarboxylate ligands bridge metal ions forming a polymeric chain. The 2‐[(1H‐imidazol‐1‐yl)methyl]‐6‐methyl‐1H‐benzimidazole ligands coordinate to the Co^II or Ni^II centres in monodentate modes through an imidazole N atom and are pendant on opposite sides of the main chain. The two structures are isomorphous. In the crystal, the one‐dimensional chains are further connected through O—H…O, O—H…N and N—H…O hydrogen bonds, leading to a three‐dimensional supramolecular architecture. In addition, the IR spectroscopic properties, PXRD patterns, thermogravimetric behaviours and fluorescence properties of both polymers have been investigated.     

mer‐Diaquabis(1H‐imidazole‐κN3)[orotato(2–)]cobalt(II)

In the title complex, mer‐diaqua[2,6‐dioxo‐1,2,3,6‐tetrahydropyrimidine‐4‐carboxylato(2−)]bis(1H‐imidazole‐κN³)cobalt(II), [Co(C₅H₂N₂O₄)(C₃H₄N₂)₂(H₂O)₂], the Co^II ion is coordinated by a deprotonated N atom and the carboxylate O atom of the orotate ligand, two imidazole N atoms and two aqua ligands in a distorted octahedral geometry. The title complex exists as discrete doubly hydrogen‐bonded dimers, and a three‐dimensional network of O—H...O and N—H...O hydrogen bonds and weak π–π interactions is responsible for crystal stabilization.     

Synthesis and characterization of two novel bimetallic macrocyclic complexes generated from 1,2,4‐triazole‐containing semi‐rigid ligands and M(NO3)2 units (M = Ni and Zn)

Bimetallic macrocyclic complexes have attracted the attention of chemists and various organic ligands have been used as molecular building blocks, but supramolecular complexes based on semi‐rigid organic ligands containing 1,2,4‐triazole have remained rare until recently. It is easier to obtain novel topologies by making use of asymmetric semi‐rigid ligands in the self‐assembly process than by making use of rigid ligands. A new semi‐rigid ligand, 3‐[(pyridin‐4‐ylmethyl)sulfanyl]‐5‐(quinolin‐2‐yl)‐4H‐1,2,4‐triazol‐4‐amine (L), has been synthesized and used to generate two novel bimetallic macrocycle complexes, namely bis{μ‐3‐[(pyridin‐4‐ylmethyl)sulfanyl]‐5‐(quinolin‐2‐yl)‐4H‐1,2,4‐triazol‐4‐amine}bis[(methanol‐κO)(nitrato‐κ²O,O′)nickel(II)] dinitrate, [Ni₂(NO₃)₂(C₁₇H₁₄N₆S)₂(CH₃OH)₂](NO₃)₂, (I), and bis{μ‐3‐[(pyridin‐4‐ylmethyl)sulfanyl]‐5‐(quinolin‐2‐yl)‐4H‐1,2,4‐triazol‐4‐amine}bis[(methanol‐κO)(nitrato‐κ²O,O′)zinc(II)] dinitrate, [Zn₂(NO₃)₂(C₁₇H₁₄N₆S)₂(CH₃OH)₂](NO₃)₂, (II), by solution reactions with the inorganic salts M(NO₃)₂ (M = Ni and Zn, respectively) in mixed solvents. In (I), two Ni^II cations with the same coordination environment are linked by L ligands through Ni—N bonds to form a bimetallic ring. Compound (I) is extended into a two‐dimensional network in the crystallographic ac plane via N—H…O, O—H…N and O—H…O hydrogen bonds, and neighbouring two‐dimensional planes are parallel and form a three‐dimensional structure via π–π stacking. Compound (II) contains two bimetallic rings with the same coordination environment of the Zn^II cations. The Zn^II cations are bridged by L ligands through Zn—N bonds to form the bimetallic rings. One type of bimetallic ring constructs a one‐dimensional nanotube via O—H…O and N—H…O hydrogen bonds along the crystallographic a direction, and the other constructs zero‐dimensional molecular cages via O—H…O and N—H…O hydrogen bonds. They are interlinked into a two‐dimensional network in the ac plane through extensive N—H…O hydrogen bonds, and a three‐dimensional supramolecular architecture is formed via π–π interactions between the centroids of the benzene rings of the quinoline ring systems.     

Two nickel(II) bis[(pyridin‐2‐yl)methyl]amine complexes with homophthalic and benzene‐1,2,4,5‐tetracarboxylic acids

Two new Ni^II complexes involving the ancillary ligand bis[(pyridin‐2‐yl)methyl]amine (bpma) and two different carboxylate ligands, i.e. homophthalate [hph; systematic name: 2‐(2‐carboxylatophenyl)acetate] and benzene‐1,2,4,5‐tetracarboxylate (btc), namely catena‐poly[[aqua{bis[(pyridin‐2‐yl)methyl]amine‐κ³N,N′,N′′}nickel(II)]‐μ‐2‐(2‐carboxylatophenyl)aceteto‐κ²O:O′], [Ni(C₉H₆O₄)(C₁₂H₁₃N₃)(H₂O)]_n, and (μ‐benzene‐1,2,4,5‐tetracarboxylato‐κ⁴O¹,O²:O⁴,O⁵)bis(aqua{bis[(pyridin‐2‐yl)methyl]amine‐κ³N,N′,N′′}nickel(II)) bis(triaqua{bis[(pyridin‐2‐yl)methyl]amine‐κ³N,N′,N′′}nickel(II)) benzene‐1,2,4,5‐tetracarboxylate hexahydrate, [Ni₂(C₁₀H₂O₈)(C₁₂H₁₃N₃)₂(H₂O)₂]·[Ni(C₁₂H₁₃N₃)(H₂O)₃]₂(C₁₀H₂O₈)·6H₂O, (II), are presented. Compound (I) is a one‐dimensional polymer with hph acting as a bridging ligand and with the chains linked by weak C—H...O interactions. The structure of compound (II) is much more complex, with two independent Ni^II centres having different environments, one of them as part of centrosymmetric [Ni(bpma)(H₂O)]₂(btc) dinuclear complexes and the other in mononuclear [Ni(bpma)(H₂O)₃]²⁺ cations which (in a 2:1 ratio) provide charge balance for btc⁴⁻ anions. A profuse hydrogen‐bonding scheme, where both coordinated and crystal water molecules play a crucial role, provides the supramolecular linkage of the different groups.     

A helical zinc(II) coordination polymer assembled from 1,3‐bis[(pyridin‐3‐yl)methoxy]benzene and benzene‐1,4‐dicarboxylic acid

In catena‐poly[[aqua[1,3‐bis(pyridine‐3‐ylmethoxy)benzene‐κN]zinc(II)]‐μ₂‐benzene‐1,4‐dicarboxylato‐κ²O¹:O⁴], [Zn(C₈H₄O₄)(C₁₈H₁₆N₂O₂)(H₂O)]_n, each Zn^II centre is tetrahedrally coordinated by two O atoms of bridging carboxylate groups from two benzene‐1,4‐dicarboxylate anions (denoted L²⁻), one O atom from a water molecule and one N atom from a 1,3‐bis[(pyridin‐3‐yl)methoxy]benzene ligand (denoted bpmb). (Aqua)O—H...N hydrogen‐bonding interactions induce the formation of one‐dimensional helical [Zn(L)(bpmb)(H₂O)]_n chains which are interlinked through (aqua)O—H...O hydrogen‐bonding interactions, producing two‐dimensional corrugated sheets.     

catena‐Poly[[nickel(II)‐μ2‐[1,3‐bis(imidazol‐1‐ylmethyl)benzene‐κ2N3:N3′]‐μ2‐(5‐carboxybenzene‐1,3‐dicarboxylato‐κ4O1,O1′:O3,O3′)] 0.41‐hydrate]

The title compound, {[Ni(C₉H₄O₆)(C₁₄H₁₄N₄)]·0.41H₂O}_n, exhibits a three‐dimensional hydrogen‐bonded supramolecular framework. The Ni^II cation is six‐coordinated in a distorted triangular prism defined by two N atoms from two 1,3‐bis(imidazol‐l‐ylmethyl)benzene (bix) ligands and four O atoms from two 5‐carboxybenzene‐1,3‐dicarboxylate (HBTC) dianions. The bix molecules and HBTC dianions both act as bidentate ligands, linking the Ni^II cations to form a one‐dimensional coordination polymer. A two‐dimensional wave‐like net is constructed by O—H...O hydrogen bonds linking adjacent chains. Partially occupied solvent water molecules fill the cavities and link these layers to form a three‐dimensional supramolecular structure via O—H...O hydrogen bonds. The title compound was also characterized by powder X‐ray diffraction and thermogravimetric analysis.     

A new one‐dimensional CdII coordination polymer with a two‐dimensional layered structure incorporating 2‐[(1H‐imidazol‐1‐yl)methyl]‐1H‐benzimidazole and benzene‐1,2‐dicarboxylate ligands

The N‐heterocyclic ligand 2‐[(1H‐imidazol‐1‐yl)methyl]‐1H‐benzimidazole (imb) has a rich variety of coordination modes and can lead to polymers with intriguing structures and interesting properties. In the coordination polymer catena‐poly[[cadmium(II)‐bis[μ‐benzene‐1,2‐dicarboxylato‐κ⁴O¹,O^1′:O²,O^2′]‐cadmium(II)‐bis{μ‐2‐[(1H‐imidazol‐1‐yl)methyl]‐1H‐benzimidazole}‐κ²N²:N³;κ²N³:N²] dimethylformamide disolvate], {[Cd(C₈H₄O₄)(C₁₁H₁₀N₄)]·C₃H₇NO}_n, (I), each Cd^II ion exhibits an irregular octahedral CdO₄N₂ coordination geometry and is coordinated by four O atoms from two symmetry‐related benzene‐1,2‐dicarboxylate (1,2‐bdic²⁻) ligands and two N atoms from two symmetry‐related imb ligands. Two Cd^II ions are connected by two benzene‐1,2‐dicarboxylate ligands to generate a binuclear [Cd₂(1,2‐bdic)₂] unit. The binuclear units are further connected into a one‐dimensional chain by pairs of bridging imb ligands. These one‐dimensional chains are further connected through N—H…O hydrogen bonds and π–π interactions, leading to a two‐dimensional layered structure. The dimethylformamide solvent molecules are organized in dimeric pairs via weak interactions. In addition, the title polymer exhibits good fluorescence properties in the solid state at room temperature.     

Mononuclear and dinuclear bromide–nitrite cadmium(II) complexes with related 1,4‐diazabicyclo[2.2.2]octane ligands

The title compounds, di‐μ‐bromido‐bis[bromido(1‐carboxymethyl‐4‐aza‐1‐azoniabicyclo[2.2.2]octane‐κN⁴)(nitrito‐κ²O,O′)cadmium(II)] dihydrate, [Cd₂Br₄(C₈H₁₅N₂O₂)₂(NO₂)₂]·2H₂O, (I), and aquabromido(1‐cyanomethyl‐4‐aza‐1‐azoniabicyclo[2.2.2]octane‐κN⁴)bis(nitrito‐κ²O,O′)cadmium(II) monohydrate, [CdBr(C₈H₁₄N₃)(NO₂)₂(H₂O)]·H₂O, (II), are two‐dimensional hydrogen‐bonded metal–organic hybrid complexes. In (I), the complex is situated on a centre of inversion so that each symmetry‐related Cd^II atom is coordinated by two bridging Br atoms, one monodentate Br atom, one chelating nitrite ligand and one organic ligand, yielding a significantly distorted octahedral geometry. The combination of O—H...O and O—H...Br hydrogen bonds produces centrosymmetric R₆⁶(16) ring motifs, resulting in two‐dimensional layers parallel to the ab plane. In contrast, the complex molecule in (II) is mononuclear, with the Cd^II atom seven‐coordinated by two bidentate nitrite groups, one N atom from the organic ligand, one monodentate Br atom and a water O atom in a distorted pentagonal–bipyramidal environment. The combination of O—H...O and O—H...Br hydrogen bonds produces R₅⁴(14) and R₃³(8) rings which lead to two‐dimensional layers parallel to the ac plane.     

A new two‐dimensional cadmium coordination polymer with 1H‐imidazole‐4‐carboxylate and oxalate

The title compound, poly[aqua(μ₂‐1H‐imidazole‐4‐carboxylato‐κ³N³,O:O′)hemi(μ₂‐oxalato‐κ⁴O¹,O²:O^1′,O^2′)cadmium(II)], [Cd(C₄H₃N₂O₂)(C₂O₄)_0.5(H₂O)]_n, exhibits a two‐dimensional network. The Cd^II cation is coordinated to one N atom and two carboxylate O atoms from two 1H‐imidazole‐4‐carboxylate (Himc) ligands, two carboxylate O atoms from the bridging oxalate anion and one ligated water molecule; these six donor atoms form a distorted octahedral configuration. The oxalate anion lies on a centre of inversion. The Himc ligands connect the Cd^II cations to form –Cd–Himc–Cd–Himc–Cd– zigzag chains, with a Cd...Cd separation of 5.8206 (6) Å along the b direction, which are further linked by tetradentate oxalate anions to generate a two‐dimensional herringbone architecture in the ab plane. These layers are extended to form a three‐dimensional supramolecular framework via O—H...O and N—H...O hydrogen bonds and π–π stacking interactions. The solid‐state photoluminscent behaviour of the title compound has been investigated at room temperature.     

A new three‐dimensional CdII supramolecular framework constructed from the 1‐[(1H‐tetrazol‐5‐yl)methyl]‐1,4‐diazoniabicyclo[2.2.2]octane ligand

A new tetrazole–metal supramolecular compound, di‐μ‐chlorido‐bis(trichlorido{1‐[(1H‐tetrazol‐5‐yl‐κN²)methyl]‐1,4‐diazoniabicyclo[2.2.2]octane}cadmium(II)), [Cd₂(C₈H₁₆N₆)₂Cl₈], has been synthesized and structurally characterized by single‐crystal X‐ray diffraction. In the structure, each Cd^II cation is coordinated by five Cl atoms (two bridging and three terminal) and by one N atom from the 1‐[(1H‐tetrazol‐5‐yl)methyl]‐1,4‐diazoniabicyclo[2.2.2]octane ligand, adopting a slightly distorted octahedral coordination geometry. The bridging bicyclo[2.2.2]octane and chloride ligands link the Cd^II cations into one‐dimensional ribbon‐like N—H...Cl hydrogen‐bonded chains along the b axis. An extensive hydrogen‐bonding network formed by N—H...Cl and C—H...Cl hydrogen bonds, and interchain π–π stacking interactions between adjacent tetrazole rings, consolidate the crystal packing, linking the poymeric chains into a three‐dimensional supramolecular network.     

Bis(5‐aminotetrazole‐1‐acetato‐κO)tetraaquacobalt(II) and catena‐poly[[cadmium(II)]‐bis(μ‐5‐aminotetrazole‐1‐acetato‐κ3N4:O,O′)]

The Co^II atom in bis(5‐aminotetrazole‐1‐acetato)tetraaquacobalt(II), [Co(C₃H₄N₅O₂)₂(H₂O)₄], (I), is octahedrally coordinated by six O atoms from two 5‐aminotetrazole‐1‐acetate (atza) ligands and four water molecules. The molecule has a crystallographic centre of symmetry located at the Co^II atom. The molecules of (I) are interlinked by hydrogen‐bond interactions, forming a two‐dimensional supramolecular network structure in the ac plane. The Cd^II atom in catena‐poly[[cadmium(II)]‐bis(μ‐5‐aminotetrazole‐1‐acetato], [Cd(C₃H₄N₅O₂)₂]_n, (II), lies on a twofold axis and is coordinated by two N atoms and four O atoms from four atza ligands to form a distorted octahedral coordination environment. The Cd^II centres are connected through tridentate atza bridging ligands to form a two‐dimensional layered structure extending along the ab plane, which is further linked into a three‐dimensional structure through hydrogen‐bond interactions.     

A novel two‐dimensional zinc(II) coordination polymer with 6‐mercaptonicotinic acid

The novel title Zn^II coordination polymer, poly[bis(μ‐6‐thioxo‐1,6‐dihydropyridine‐3‐carboxylato‐κ²S:O)zinc(II)], [Zn(C₆H₄NO₂S)₂]_n, consists of two crystallographically independent zinc centers and two 6‐mercaptonicotinate (Hmna⁻) ligands. Each Zn^II atom is four‐coordinated and lies at the center of a distorted tetrahedral ZnS₂O₂ coordination polyhedron, bridged by four Hmna⁻ ligands to form a two‐dimensional (4,4)‐network. Each Hmna⁻ ion acts as a bridging bidentate ligand, coordinating to two Zn^II atoms through the S atom and a carboxyl O atom. The metal centers reside on twofold rotation axes. The coordination mode of the S atoms and N—H...O hydrogen‐bonding interactions between the protonated N atoms and the uncoordinated carboxyl O atoms give the extended structure a wavelike form.     

Monodentate and bridging behaviour of the sulfur‐containing ligand 4′‐[4‐(methylsulfanyl)phenyl]‐4,2′:6′,4′′‐terpyridine in two discrete zinc(II) complexes with acetylacetonate

The Zn complexes bis(acetylacetonato‐κ²O,O′)bis{4′‐[4‐(methylsulfanyl)phenyl]‐4,2′:6′,4′′‐terpyridine‐κN¹}zinc(II), [Zn(C₅H₇O₂)₂(C₂₂H₁₇N₃S)₂], (I), and {μ‐4′‐[4‐(methylsulfanyl)phenyl]‐4,2′:6′,4′′‐terpyridine‐κ²N¹:N^1′′}bis[bis(acetylacetonato‐κ²O,O′)zinc(II)], [Zn₂(C₅H₇O₂)₄(C₂₂H₁₇N₃S)], (II), are discrete entities with different nuclearities. Compound (I) consists of two centrosymmetrically related monodentate 4′‐[4‐(methylsulfanyl)phenyl]‐4,2′:6′,4′′‐terpyridine (L1) ligands binding to one Zn^II atom sitting on an inversion centre and two centrosymmetrically related chelating acetylacetonate (acac) groups which bind via carbonyl O‐atom donors, giving an N₂O₄ octahedral environment for Zn^II. Compound (II), however, consists of a bis‐monodentate L1 ligand bridging two Zn^II atoms from two different Zn(acac)₂ fragments. Intra‐ and intermolecular interactions are weak, mainly of the C—H...π and π–π types, mediating similar layered structures. In contrast to related structures in the literature, sulfur‐mediated nonbonding interactions in (II) do not seem to have any significant influence on the supramolecular structure.     

(6‐Oxido‐2‐oxo‐1,2‐dihydropyrimidine‐5‐carboxylato‐κ2O5,O6)bis[2‐(2‐pyridyl)‐1H‐benzimidazole‐κ2N2,N3]manganese(II) monohydrate

In the title compound, [Mn(C₅H₂N₂O₄)(C₁₂H₉N₃)₂]·H₂O, the Mn^II centre is surrounded by three bidentate chelating ligands, namely, one 6‐oxido‐2‐oxo‐1,2‐dihydropyrimidine‐5‐carboxylate (or uracil‐5‐carboxylate, Huca²⁻) ligand [Mn—O = 2.136 (2) and 2.156 (3) Å] and two 2‐(2‐pyridyl)‐1H‐benzimidazole (Hpybim) ligands [Mn—N = 2.213 (3)–2.331 (3) Å], and it displays a severely distorted octahedral geometry, with cis angles ranging from 73.05 (10) to 105.77 (10)°. Intermolecular N—H...O hydrogen bonds both between the Hpybim and the Huca²⁻ ligands and between the Huca²⁻ ligands link the molecules into infinite chains. The lattice water molecule acts as a hydrogen‐bond donor to form double O...H—O—H...O hydrogen bonds with the Huca²⁻ O atoms, crosslinking the chains to afford an infinite two‐dimensional sheet; a third hydrogen bond (N—H...O) formed by the water molecule as a hydrogen‐bond acceptor and a Hpybim N atom further links these sheets to yield a three‐dimensional supramolecular framework. Possible partial π–π stacking interactions involving the Hpybim rings are also observed in the crystal structure.