Poly[[tetraaqua(μ7‐pyridine‐2,3,5,6‐tetracarboxylato)dicadmium(II)] monohydrate]

The title compound, {[Cd₂(C₉HNO₈)(H₂O)₄]·H₂O}_n, consists of two crystallographically independent Cd^II cations, one tetrabasic pyridine‐2,3,5,6‐tetracarboxylate (pdtc) anion, four coordinated water molecules and one solvent water molecule. The Cd^II cations have distorted square‐antiprismatic (one pyridine N, six carboxylate O and one water O atom) and octahedral (three carboxylate O and three water O atoms) coordination environments. Each pdtc ligand employs its pyridine and carboxylate groups to chelate and bridge seven Cd^II cations. The square‐antiprismatic coordinated Cd^II cations are linked by pdtc ligands into a lamellar framework structure, while the octahedral coordinated Cd^II cations are bridged by the μ₂‐carboxylate O atoms and the pdtc ligands into a chain network that further joins neighbouring lamellae into a three‐dimensional porous network. The cavities are filled with solvent water molecules that are linked to the host through complex hydrogen bonding.     

Poly[[diaqua(μ3‐3‐nitrophthalato)calcium(II)] monohydrate]

The title 3‐nitrophthalate–calcium coordination polymer, {[Ca(C₈H₃NO₆)(H₂O)₂]·H₂O}_n, crystallizes as a one‐dimensional framework. The Ca^II centre has a distorted pentagonal–bipyramidal geometry, being seven‐coordinated by five O atoms from three different 3‐nitrophthalate groups and by two water molecules, resulting in a one‐dimensional zigzag chain along the a‐axis direction by the interconnection of the four O atoms from the two carboxylate groups. There is a D3 water cluster composed of the coordinated and the solvent water molecules within such chains. Adjacent chains are aggregated into two‐dimensional layers via hydrogen bonds in the c‐axis direction. The whole three‐dimensional structure is further stabilized by weak O—H...O hydrogen bonds between the O atoms of the nitro group and the water molecules.     

Poly[[pentaaquasulfato‐μ4‐(R,R)‐tartrato‐dicadmium(II)] trihydrate]

The asymmetric unit in the title compound, {[Cd₂(C₄H₄O₆)(SO₄)(H₂O)₅]·3H₂O}_n, is composed of two cadmium cations, one (R,R)‐tartrate and one sulfate anion, five aqua ligands and three solvent water molecules. One of the cadmium ions is coordinated in an octahedral environment, whereas the second is surrounded by seven O atoms in a pentagonal–bipyramidal geometry. Both types of coordination polyhedra form two sets of perpendicular non‐intersecting polymeric chains. CdO₆ octahedra share two corners, while CdO₇ units are joined by a bridging carboxylate group. An extensive hydrogen‐bond pattern involving all of the OH groups contributes to the stabilization of the structure.     

Poly[[tetraaquatris(μ3‐2,2‐dimethylmalonato)dilanthanum(III)] monohydrate]

In the title complex, {[La₂(C₅H₆O₄)₃(H₂O)₄]·H₂O}_n, the La atoms are connected by bridging O atoms from carboxylate groups to build, through centres of inversion, two‐dimensional layers parallel to the ac plane containing decanuclear 20‐membered rings. The coordinated water molecules are involved in intralayer hydrogen‐bond interactions. Adjacent layers are linked via hydrogen bonding to the solvent water molecules. This work represents the first example of a new substituted malonate–lanthanide complex.     

Poly[[aqua(μ‐2,2‐dimethylmalonato)barium(II)] 2,2‐dimethylmalonic acid solvate]

In the title complex, {[Ba(C₅H₆O₄)(H₂O)]·C₅H₈O₄}_n, the neutral dimethylmalonic acid molecules and the dianionic (dimethylmalonato)barium metal–organic framework are linked by cocrystallization. The Ba atom, in a distorted monocapped square‐antiprismatic geometry, is nine‐coordinated by seven O atoms of four different dimethylmalonate groups and by two water molecules. This arrangement generates a two‐dimensional layer parallel to the bc plane. Two such layers sandwich another layer composed of neutral dimethylmalonic acid molecules that are involved in intermolecular hydrogen bonds within this layer and to neighboring layers. This complex is different from the dimethylmalonate–Ba complex reported previously. The title compound displays a novel structure type and represents a new member of the substituted malonate series of alkaline earth complexes.     

Poly[[aqua­tetra­imidazole­di‐μ‐phthalato‐dicopper(II)] monohydrate]

The title complex, {[Cu₂(C₈H₄O₄)₂(C₃H₄N₂)₄(H₂O)]·H₂O}_n, is a three‐dimensional polymer formed through bridging by phthalate dianions of two different Cu^II cations and a network of O(N)—H⋯O hydrogen bonds. The Cu—O and Cu—N inter­action distances are in the ranges 2.0020 (16)–2.4835 (17) and 1.968 (2)–1.9855 (19) Å, respectively. The structure is composed of alternating polymer chains parallel to the c axis, with a shortest Cu⋯Cu distance of 6.3000 (5) Å.     

Poly[[diaqua(μ3‐2,2‐dimethylmalonato)cadmium(II)] tetrahydrate]

In the title complex, {[Cd(C₅H₆O₄)(H₂O)₂]·4H₂O}_n, the dimethylmalonate–cadmium metal–organic framework co‐exists with an extended structure of water molecules, which resembles a sodalite‐type framework. In the asymmetric unit, there are five independent solvent water molecules, two of which are in special positions. The Cd atoms are eight‐coordinated in a distorted square‐antiprismatic geometry by six O atoms of three different dimethylmalonate groups and by two water molecules, and form a two‐dimensional honeycomb layer parallel to the bc plane. Two such layers sandwich the hydrogen‐bonded water layer, which has a sodalite‐type structure with truncated sodalite units composed of coordinated and solvent water molecules. This work is the first example of a dimethylmalonate cadmium complex containing truncated sodalite‐type water clusters.     

Poly[[μ‐aqua‐bis­(μ‐2,4‐dichloro­phen­oxy­acetato)barium(II)] monohydrate]

In the title coordination polymer, {[Ba(C₈H₅Cl₂O₃)₂(H₂O)]·H₂O}_n, each Ba^II atom is nine‐coordinated by six carboxyl­ate O atoms and one ether O atom from five symmetry‐related 2,4‐dichloro­phenoxy­acetate ligands, and by two O atoms from water mol­ecules, thus defining a distorted tricapped trigonal prism. The Ba^II ions are bridged by bidentate water mol­ecules and by tridentate and tetra­dentate 2,4‐dichloro­phenoxy­acetate groups, leading to a two‐dimensional layer structure. The crystal structure is further stabilized by hydrogen‐bonding inter­actions within each layer.     

Poly[[μ2‐4,4′‐bipyridine‐di‐μ3‐sulfito‐dizinc(II)] monohydrate]

The title compound, {[Zn₂(SO₃)₂(C₁₀H₈N₂)]·H₂O}_n, is a two‐dimensional polymer built up of a [ZnSO₃]_n chain evolving around a 2₁ axis and inter­connected by a 4,4′‐bipyridine spacer. The resulting two‐dimensional structures are linked, in turn, by hydrogen bonding mediated by the solvent water mol­ecule. The organic ligand lies on a centre of symmetry located on the mid‐point of the bond between the rings, while the solvent water mol­ecule is halved by a twofold axis passing through the O atom.     

Poly[[aqua‐μ3‐2,2‐dimethylmalonato‐copper(II)] monohydrate] and poly[aqua‐μ3‐2,2‐dimethylmalonato‐copper(II)]

The coordination mode of the dimethylmalonate ligand in the two title Cu^II complexes, {[Cu(C₅H₃O₄)(H₂O)]·H₂O}_n, (I), and [Cu(C₅H₃O₄)(H₂O)]_n, (II), is the same, with chelated six‐membered, bis‐monodentate and bridging bonding modes. However, the coordination environment of the Cu^II atoms, the connectivity of their metal–organic frameworks and their hydrogen‐bonding interactions are different. Complex (I) has a perfect square‐pyramidal Cu^II environment with the aqua ligand in the apical position, and only one type of square grid consisting of Cu^II atoms linked via carboxylate bridges to three dimethylmalonate ligands, with weak hydrogen‐bond interactions within and between its two‐dimensional layers. Complex (II) has a coordination geometry that is closer to square pyramidal than trigonal bipyramidal for its Cu^II atoms with the aqua ligand now in the basal plane. Its two‐dimensional layer structure comprises two alternating grids, which involve two and four different dimethylmalonate anions, respectively. There are strong hydrogen bonds only within its layers.     

Hydrothermal synthesis and extended structure of poly[aqua(μ5‐ethylenediaminetetraacetato)dizinc(II)]

In the extended structure of the title compound, [Zn₂(C₁₀H₁₂N₂O₈)(H₂O)], prepared under hydrothermal conditions, there are two distinct Zn^II sites. The first, with octahedral geometry, bonds to two N and three O atoms from one ethylenediaminetetraacetate tetraanion (EDTA) and one water molecule. The second, with tetrahedral geometry, coordinates to O atoms from four different EDTA ligands. The EDTA ligand almost encapsulates the octahedral Zn^II ion and binds to four symmetry‐related tetrahedral Zn^II ions, hence generating the extended structure. One noncoordinated O‐atom site on the EDTA ligand connects to the water molecule by hydrogen bonding. Structural comparisons are made with other compounds containing zinc, EDTA and water.     

Poly[[aqua­copper(II)]‐μ‐adamantane‐1,3‐diacetato]

In the title compound, [Cu(C₁₄H₁₈O₄)(H₂O)]_n, each Cu^II atom bonds to four O atoms of four adamantanediacetate (ada) ligands in equatorial positions and an O atom from a water mol­ecule in the apical position. Two adjacent Cu^II atoms form a paddle‐wheel unit with four ada ligands. The distance between the two Cu atoms is 2.5977 (3) Å. A crystallographic inversion center is located at the center of the Cu–Cu core. Each Cu₂(ada)₄ paddle‐wheel further bonds to four adjacent identical paddle‐wheel units, generating a two‐dimensional layered structure of Cu(ada)(H₂O) with a 4⁴ topology.     

Poly[[diaqua­cadmium(II)]‐μ4‐[N‐(phosphonato­methyl)ammonio]acetato]

The title compound, [Cd(C₃H₆NO₅P)(H₂O)₂]_n, is a three‐dimensional polymeric complex. The asymmetric unit contains one Cd atom, one N‐(phosphono­methyl)glycine zwitterion [(O⁻)₂OPCH₂NH₂⁺CH₂COO⁻] and two water mol­ecules. The coordination geometry is a distorted CdO₆ octa­hedron. Each N‐(phosphono­methyl)glycine ligand bridges four adjacent water‐coordinated Cd cations through three phospho­nate O atoms and one carboxyl­ate O atom, like a regular PO₄³⁻ group in zeolite‐type frameworks. One‐dimensional zigzag (–O—P—C—N—C—C—O—Cd–)_n chains along the [101] direction are linked to one another via Cd—O—P bridges and form a three‐dimensional network motif with three types of channel systems. The variety of O—H⋯O and N—H⋯O hydrogen bonds is likely to be responsible for stabilizing the three‐dimensional network structure and preventing guest mol­ecules from entering into the channels.     

Poly[[diaqua(N,N‐dimethylformamide‐κO)manganese(II)]‐μ3‐sulfato]

In the title complex, [Mn(SO₄)(C₃H₇NO)(H₂O)₂]_n, each Mn^II ion has a distorted octahedral geometry formed by three O atoms of three different sulfate groups, one O atom of a dimethylformamide ligand and two water molecules. The sulfate groups act as tridentate bridging ligands connecting the Mn^II ions into a two‐dimensional layer structure which can be regraded as a 4.8² network.     

Poly[[di‐μ‐aqua‐tetraaquadi‐μ‐hydroxido‐bis(μ3‐3‐nitrophthalato)tricopper(II)] dihydrate]

The novel title complex, {[Cu₃(C₈H₃NO₆)₂(OH)₂(H₂O)₆]·2H₂O}_n, has a one‐dimensional polymeric double chain structure where the three Cu atoms are linked by μ₂‐OH and μ₂‐H₂O groups, and these trinuclear centres are bridged by two 3‐nitrophthalate ligands. The asymmetric unit contains one and a half crystallographically independent Cu atoms (one lying on a centre of inversion), both coordinated by six O atoms and exhibiting distorted octahedral coordination geometries, but with different coordination environments. Each 3‐nitrophthalate ligand connects to three Cu atoms through two O atoms of one carboxylate group and one O atom of the nitro group. The remaining carboxylate group is free and is involved in intrachain hydrogen bonds, reinforcing the chain linkage.     

catena‐Poly[[bis[pentaaquaerbium(III)]‐μ‐benzenehexacarboxylato] tetrahydrate]

The title compound is composed of one‐dimensional polymeric {[Er₂(C₁₂O₁₂)(H₂O)₁₀]·4H₂O}_n chains containing Er in a slightly distorted antiprismatic eightfold coordination. The benzene­hexa­carboxyl­ate ion is located about an inversion centre. Water mol­ecules of crystallization, linked by hydrogen bonding to water mol­ecules of the rare earth coordination spheres or the carboxyl­ate groups of the organic ligands, fill the space generated by the packing of the separated chains.     

Zoledronate complexes. I. Poly[[μ2‐aqua[μ3‐1‐hydroxy‐2‐(1H,3H‐imidazol‐3‐ium‐1‐yl)ethylidenediphosphonato]potassium(I)] monohydrate]

The title compound, {[K(C₅H₉N₂O₇P₂)(H₂O)]·H₂O}_n, is polymeric and consists of layers parallel to (001) interconnected by hydrogen‐bonding and π–π interactions. The K⁺ cation is eightfold coordinated in a KO₈ environment by O atoms from three different chelating zoledronate units and two coordinated water molecules. The zoledronate group presents its usual zwitterionic character, with negative charges in the singly protonated phosphonate groups and a positive charge at the protonated imidazole N atom. The anion binds to three different K⁺ cations in a (so far unreported) triply chelating manner. Intra‐ and interplanar interactions are enhanced by a variety of hydrogen bonds involving all available O—H and N—H donors. A strong imidazole–phosphonate C—H...O interaction is present in the structure.     

Poly[[bis(pyridin‐3‐ol)manganese(II)]‐di‐μ‐pyridin‐3‐olato]

In the title complex, [Mn(C₅H₄NO)₂(C₅H₅NO)₂]_n or [Mn(μ‐3‐PyO)₂(3‐PyOH)₂]_n (3‐PyO⁻ is the pyridin‐3‐olate anion and 3‐PyOH is pyridin‐3‐ol), the Mn^II atom lies on an inversion centre and has octahedral geometry, defined by two N atoms and two deprotonated exocyclic O atoms of symmetry‐related pyridin‐3‐olate ligands [Mn—N = 2.3559 (14) Å and Mn—O = 2.1703 (11) Å], as well as two N atoms of terminal 3‐PyOH ligands [Mn—N = 2.3482 (13) Å]. The Mn^II atoms are bridged by the deprotonated pyridin‐3‐olate anion into a layer structure, generating sheets in the (01) plane. These sheets are linked by O—H⋯O hydrogen bonds. There are also π–π and C—H⋯π interactions in the crystal structure.     

catena‐Poly[[bis­[μ‐2,4‐dichloro‐6‐(2‐pyridyl­methyl­imino­meth­yl)phenolato]dicadmium(II)]‐di‐μ‐thiocyanato]

The title complex, [Cd₂(C₁₃H₉Cl₂N₂O)₂(NCS)₂]_n, is a novel thio­cyanate‐bridged polynuclear cadmium(II) compound. The Cd^II atom is six‐coordinated in a distorted octa­hedral configuration, with one O and two N atoms of one Schiff base mol­ecule and one terminal S atom of a bridging thio­cyanate ligand defining the equatorial plane, and one terminal N atom of another bridging thio­cyanate ligand and one O atom of another Schiff base mol­ecule occupying axial positions. Adjacent inversion‐related [2,4‐dichloro‐6‐(2‐pyridylmethyl­imino­meth­yl)phenolato]cadmium(II) moieties utilize bridging phenolate and thio­cyanate groups to form polymeric chains running along the b axis.     

Poly[[tetraaquabis(μ2‐2‐nitroterephthalato‐κ3O1:O4,O4′)(μ2‐piperazine‐κ3N:N′)dicadmium(II)] dihydrate]

In the title complex, {[Cd₂(C₈H₃NO₆)₂(C₄H₁₀N₂)(H₂O)₄]·2H₂O}_n, the Cd^II atoms show distorted octahedral coordination. The two carboxylate groups of the dianionic 2‐nitroterephthalate ligand adopt monodentate and 1,2‐bridging modes. The piperazine molecule is in a chair conformation and lies on a crystallographic inversion centre. The Cd^II atoms are connected via three O atoms from two carboxylate groups and two N atoms from piperazine molecules to form a two‐dimensional macro‐ring layer structure. These layers are further aggregated to form a three‐dimensional structure via rich intra‐ and interlayer hydrogen‐bonding networks. This study illustrates that, by using the labile Cd^II salt and a combination of 2‐nitroterephthalate and piperazine as ligands, it is possible to generate interesting metal–organic frameworks with rich intra‐ and interlayer O—H...O hydrogen‐bonding networks.