A three‐dimensional polymeric potassium complex of 5‐sulfonobenzene‐1,2,4‐tricarboxylic acid: poly[μ‐aqua‐aqua‐μ9‐(2,4‐dicarboxy‐5‐sulfonatobenzoato)‐dipotassium(I)]

The asymmetric unit in the structure of the title compound, [K₂(C₉H₄O₉S)(H₂O)₂]_n, consists of two eight‐coordinated K^I cations, one 2,4‐dicarboxy‐5‐sulfonatobenzoate dianion (H₂SBTC²⁻), one bridging water molecule and one terminal coordinated water molecule. One K^I cation is coordinated by three carboxylate O atoms and three sulfonate O atoms from four H₂SBTC²⁻ ligands and by two bridging water molecules. The second K^I cation is coordinated by four sulfonate O atoms and three carboxylate O atoms from five H₂SBTC²⁻ ligands and by one terminal coordinated water molecule. The K^I cations are linked by sulfonate groups to give a one‐dimensional inorganic chain with cage‐like K₄(SO₃)₂ repeat units. These one‐dimensional chains are bridged by one of the carboxylic acid groups of the H₂SBTC²⁻ ligand to form a two‐dimensional layer, and these layers are further linked by the remaining carboxylate groups and the benzene rings of the H₂SBTC²⁻ ligands to generate a three‐dimensional framework. The compound displays a photoluminescent emission at 460 nm upon excitation at 358 nm. In addition, the thermal stability of the title compound has been studied.     

A two‐dimensional coordination polymer containing a two‐dimensional zinc–carboxylate layer constructed from helical chains: poly[(μ4‐benzene‐1,2‐dicarboxylato)zinc(II)]

The title compound, [Zn(C₈H₄O₄)]_n, consists of one Zn^II cation and one benzene‐1,2‐dicarboxylate dianion (BDC²⁻) as the building unit. The Zn^II cation is four‐coordinated by four carboxylate O atoms from four dianionic BDC²⁻ ligands in a distorted tetrahedral geometry. The Zn^II cations are linked by the BDC²⁻ ligands to generate a structure featuring two‐dimensional zinc–carboxylate layers containing left‐ and right‐handed helical chains. The two‐dimensional layers are stacked along the a direction. The thermal stability of the title compound has been studied.     

Poly[(μ5‐3‐carboxybenzene‐1,2‐dicarboxylato)lead(II)]: a helical lead(II) coordination polymer

In the title polymer, [Pb(C₉H₄O₆)]_n, the asymmetric unit contains a monomer of a Pb^II cation with a doubly deprotonated 3‐carboxybenzene‐1,2‐dicarboxylate dianion (1,2,3‐Hbtc²⁻). Each Pb^II centre is seven‐coordinated by seven O atoms of bridging carboxy/carboxylate groups from five 1,2,3‐Hbtc²⁻ ligands, forming a distorted pentagonal bipyramid. The Pb^II cations are bridged by 1,2,3‐Hbtc²⁻ anions, yielding two‐dimensional chiral layers. The layers are stacked above each other to generate a three‐dimensional supramolecular architecture via a combination of C—H...O interactions. The thermogravimetric and optical properties are also reported.     

A novel three‐dimensional heterometallic coordination polymer: poly[[diaquadi‐μ3‐chlorido‐μ2‐chlorido‐tri‐μ3‐nicotinato‐tricopper(I)gadolinium(III)] hemihydrate]

In the title polymeric heterometallic compound, {[Cu₃Gd(C₆H₄NO₂)₃Cl₃(H₂O)₂]·0.5H₂O}_n, comprising copper(I) and gadolinium(III) cations bridged by nicotinate (nic) ligands and chloride anions, the Gd^III centers display a bicapped trigonal prismatic geometry, defined by six carboxylate O atoms and two water molecules. For copper(I), one Cu center is three‐coordinated by three chloride ions and displays a trigonal–planar geometry; the other two Cu centers are four‐coordinated and display a very distorted tetrahedral geometry. The chloride anions act in μ₂‐ and μ₃‐bridging modes, linking the Cu^I ions into an infinite chain. The nic ligand exhibits a tridentate coordination mode, with the carboxylate O atoms linking to two Gd^III ions and the N atom linking to one Cu^I ion. Thus, a novel three‐dimensional heterometallic coordination polymer is constructed from Gd–carboxylate subunits and Cu—Cl chains. In addition, intra‐ and intermolecular O—H...O and O—H...Cl hydrogen bonds are also observed within the three‐dimensional structure. Topologically, the framework represents an unusual 3,6‐connected (4.8²)₃(4¹⁰.6⁵) net.     

A two‐dimensional cadmium(II) coordination polymer based on 5‐(pyridin‐4‐yl)isophthalic acid: poly[[tetraaquabis[μ3‐5‐(pyridin‐4‐yl)isophthalato]dicadmium(II)] pentahydrate]

The title Cd^II compound, {[Cd₂(C₁₃H₇NO₄)₂(H₂O)₄]·5H₂O}_n, was synthesized by the hydrothermal reaction of Cd(NO₃)₂·4H₂O and 5‐(pyridin‐4‐yl)isophthalic acid (H₂L). The asymmetric unit contains two crystallographically independent Cd^II cations, two deprotonated L²⁻ ligands, four coordinated water molecules and five isolated water molecules. One of the Cd^II cations adopts a six‐coordinate octahedral coordination geometry involving three O atoms from one bidentate chelating and one monodentate carboxylate group of two different L²⁻ ligands, one N atom of another L²⁻ ligand and two coordinated water molecules. The second Cd^II cation adopts a seven‐coordinate pentagonal–bipyramidal coordination geometry involving four O atoms from two bidentate chelating carboxylate groups of two different L²⁻ ligands, one N atom of another L²⁻ ligand and two coordinated water molecules. Each L²⁻ ligand bridges three Cd^II cations and, likewise, each Cd^II cation connects to three L²⁻ ligands, giving rise to a two‐dimensional graphite‐like 6³ layer structure. These two‐dimensional layers are further linked by O—H...O hydrogen‐bonding interactions to form a three‐dimensional supramolecular architecture. The photoluminescence properties of the title compound were also investigated.     

catena‐Poly[hexaaquamagnesium(II) [bis(μ3‐5‐nitro‐2‐oxidoisophthalato)dicopper(II)] dihydrate]

In the centrosymmetric dinuclear anions of the title bimetallic complex, {[Mg(H₂O)₆][Cu₂(C₈H₂NO₇)₂]·2H₂O}_n, each Cu^II ion is strongly coordinated by four O atoms in a distorted square‐planar geometry. Two of these O atoms belong to phenolate groups and the other two to carboxylate groups from 5‐nitro‐2‐oxidoisophthalate (L1) trianions, derived from 5‐nitrobenzene‐1,2,3‐tricarboxylic acid (O₂N–H₃L). The phenolate O atoms bridge the two Cu^II ions in the anion. In addition, each Cu^II cation interacts weakly with a symmetry‐related carboxylate O atom of an adjacent L1 ligand, giving a square‐pyramidal coordination geometry. The copper residue forms a ladder‐like linear coordination polymer via L1 ligands. The [Mg(H₂O)₆]²⁺ cations sit on centres of inversion. The polymeric anions, cations and free water molecules are self‐assembled into a three‐dimensional supramolecular network via O—H...O hydrogen bonds.     

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.     

A three‐dimensional PbII coordination framework: poly[[μ4‐(E)‐2,2′‐(diazene‐1,2‐diyl)dibenzoato]dimethanollead(II)]

In the title coordination polymer, [Pb(C₁₄H₈N₂O₄)(CH₃OH)₂]_n, the asymmetric unit contains half of a Pb^II cation, half of a 2,2′‐(diazene‐1,2‐diyl)dibenzoate dianionic ligand (denoted L²⁻) and one methanol ligand. Each Pb^II centre is eight‐coordinated by six O atoms of chelating/bridging carboxylate groups from four L²⁻ ligands and two O atoms from two terminal methanol ligands, forming a distorted dodecahedron. The [PbL₂(MeOH)₂] subunits are interlinked via the sharing of two carboxylate O atoms to form a one‐dimensional [PbL₂(MeOH)₂]_n chain. Adjacent chains are further connected by L²⁻ ligands, giving rise to a two‐dimensional layer, and these layers are bridged by L²⁻ linkers to afford a three‐dimensional framework with a 4¹²6³ topology.     

In situ single‐crystal to single‐crystal (SCSC) transformation of the one‐dimensional polymer catena‐poly[[diaqua(sulfato)copper(II)]‐μ2‐glycine] into the two‐dimensional polymer poly[μ2‐glycine‐μ4‐sulfato‐copper(II)]

The one‐dimensional coordination polymer catena‐poly[diaqua(sulfato‐κO)copper(II)]‐μ₂‐glycine‐κ²O:O′], [Cu(SO₄)(C₂H₅NO₂)(H₂O)₂]_n, (I), was synthesized by slow evaporation under vacuum of a saturated aqueous equimolar mixture of copper(II) sulfate and glycine. On heating the same blue crystal of this complex to 435 K in an oven, its aspect changed to a very pale blue and crystal structure analysis indicated that it had transformed into the two‐dimensional coordination polymer poly[(μ₂‐glycine‐κ²O:O′)(μ₄‐sulfato‐κ⁴O:O′:O′′:O′′)copper(II)], [Cu(SO₄)(C₂H₅NO₂)]_n, (II). In (I), the Cu^II cation has a pentacoordinate square‐pyramidal coordination environment. It is coordinated by two water molecules and two O atoms of bridging glycine carboxylate groups in the basal plane, and by a sulfate O atom in the apical position. In complex (II), the Cu^II cation has an octahedral coordination environment. It is coordinated by four sulfate O atoms, one of which bridges two Cu^II cations, and two O atoms of bridging glycine carboxylate groups. In the crystal structure of (I), the one‐dimensional polymers, extending along [001], are linked via N—H...O, O—H...O and bifurcated N—H...O,O hydrogen bonds, forming a three‐dimensional framework. In the crystal structure of (II), the two‐dimensional networks are linked via bifurcated N—H...O,O hydrogen bonds involving the sulfate O atoms, forming a three‐dimensional framework. In the crystal structures of both compounds, there are C—H...O hydrogen bonds present, which reinforce the three‐dimensional frameworks.     

Poly[[diaquamanganese(II)]‐μ3‐4‐oxido‐2‐oxo‐1,2‐dihydropyrimidine‐5‐carboxylato‐κ4O4,O5:O2:O2]

In the title compound, [Mn(C₅H₂N₂O₄)(H₂O)₂]_n, the Mn^II ion has a distorted octahedral geometry and the 4‐oxido‐2‐oxo‐1,2‐dihydropyrimidine‐5‐carboxylate (Hiso²⁻) anion acts as a μ₃:η⁴‐bridging ligand. Two oxo O atoms from different Hiso²⁻ ligands bridge two Mn^II ions, forming centrosymmetric dinuclear building blocks. Each dinuclear building block interacts with another four by the coordination of the oxide groups and carboxylate O atoms, producing a two‐dimensional framework in the ab plane. Hydrogen bonds further extend the two‐dimensional sheets into a three‐dimensional supramolecular framework.     

catena‐Poly[[[(di‐2‐pyridylamine‐κ2N2,N2′)copper(II)]‐μ‐benzene‐1,3‐dicarboxylato‐κ3O1,O1′:O3] monohydrate], a zigzag coordination polymer with strong π–π interactions

The novel title coordination polymer, {[Cu(C₈H₄O₄)(C₁₀H₉N₃)]·H₂O}_n, synthesized by the slow‐diffusion method, takes the form of one‐dimensional zigzag chains built up of Cu^II cations linked by benzene‐1,3‐dicarboxylate (ipht) anions. An exceptional characteristic of this structure is that it belongs to a small group of metal–organic polymers where ipht is coordinated as a bridging tridentate ligand with monodentate and chelate coordination of individual carboxylate groups. The Cu^II cation has a highly distorted square‐pyramidal geometry formed by three O atoms from two ipht anions and two N atoms from a di‐2‐pyridylamine (dipya) ligand. The zigzag chains, which run along the b axis, further construct a three‐dimensional metal–organic framework via strong face‐to‐face π–π interactions and hydrogen bonds. A solvent water molecule is linked to the different carboxylate groups via hydrogen bonds. Thermogravimetric and differential scanning calorimetric analyses confirm the strong hydrogen bonding.     

Bis(μ‐5‐carboxybenzene‐1,3‐dicarboxylato‐κ2O1:O3)bis[(2,2′‐bi‐1H‐imidazole‐κ2N3,N3′)zinc]

The title compound, [Zn₂(C₉H₄O₆)₂(C₆H₆N₄)₂], consists of two Zn^II ions, two 5‐carboxybenzene‐1,3‐dicarboxylate (Hbtc²⁻) dianions and two 2,2′‐bi‐1H‐imidazole (bimz) molecules. The Zn^II centre is coordinated by two carboxylate O atoms from two Hbtc²⁻ ligands and by two imidazole N atoms of a bimz ligand, in a distorted tetrahedral coordination geometry. Two neighbouring Zn^II ions are bridged by a pair of Hbtc²⁻ ligands, forming a discrete binuclear [Zn₂(Hbtc)₂(bimz)₂] structure lying across an inversion centre. Hydrogen bonds between carboxyl H atoms and carboxylate O atoms and between imidazole H atoms and carboxylate O atoms link the binuclear units. These binuclear units are further extended into a three‐dimensional supramolecular structure through extensive O—H...O and N—H...O hydrogen bonds. Moreover, the three‐dimensional nature of the crystal packing is reinforced by the π–π stacking. The title compound exhibits photoluminescence in the solid state, with an emission maximum at 415 nm.     

Poly[tetra‐μ2‐l‐lactato‐indium(III)sodium(I)]

The asymmetric unit of the title compound, [InNa(C₃H₅O₃)₄]_n, consists of one In^III ion, one Na^I ion and four crystallographically independent l ‐lactate monoanions. The coordination of the In^III ion is composed of five carboxylate O and two hydroxy O atoms in a distorted pentagonal–bipyramidal coordination geometry. The Na^I ion is six‐coordinated by four carboxylate O atoms and two hydroxy O atoms from four l ‐lactate ligands in a distorted octahedral geometry. Each In^III ion is coordinated by four surrounding l ‐lactate ligands to form an [In(l ‐lactate)₄]⁻ unit, which is further linked by Na^I ions through Na—O bonds to give a two‐dimensional layered structure. Hydrogen bonds between the hydroxy groups and carboxylate O atoms are observed between neighbouring layers.     

catena‐Poly[[[aqua[3‐(2‐pyridylsulfanyl)propionato N‐oxide‐κO1]copper(II)]‐μ‐[3‐(2‐pyridylsulfanyl)propionato N‐oxide‐κ3O3:O1,O1′] dihydrate]

In the title complex, {[Cu(C₈H₈NO₃S)₂(H₂O)]·2H₂O}_n, the Cu^II cation has a distorted square‐pyramidal coordination environment consisting of five O atoms, one from a water molecule, one from an N—O group and the other three from the carboxylate groups of two 3‐(2‐pyridylsulfanyl)propionate N‐oxide anions. The aqua[3‐(2‐pyridylsulfanyl)propionato N‐oxide]copper(II) moieties are bridged by 3‐(2‐pyridylsulfanyl)propionate N‐oxide anions to form an infinite three‐dimensional coordination polymer with a zigzag chain structure. The crystal structure is stabilized by hydrogen bonds.     

A three‐dimensional cadmium(II) coordination polymer: poly[[[μ‐4,4′‐(propane‐1,3‐diyl)dipyridine‐κ2N:N](μ‐3,3′‐thiodipropionato‐κ3O,O′:O)cadmium(II)] monohydrate]

In the title coordination polymer, {[Cd(C₆H₈O₄S)(C₁₃H₁₄N₂)]·H₂O}_n, the Cd^II atom displays a distorted octahedral coordination, formed by three carboxylate O atoms and one S atom from three different 3,3′‐thiodipropionate ligands, and two N atoms from two different 4,4′‐(propane‐1,3‐diyl)dipyridine ligands. The Cd^II centres are bridged through carboxylate O atoms of 3,3′‐thiodipropionate ligands and through N atoms of 4,4′‐(propane‐1,3‐diyl)dipyridine ligands to form two different one‐dimensional chains, which intersect to form a two‐dimensional layer. These two‐dimensional layers are linked by S atoms of 3,3′‐thiodipropionate ligands from adjacent layers to form a three‐dimensional network.     

A novel two‐dimensional cadmium(II) complex: poly[diaquatris(μ4‐cyclohexane‐1,4‐dicarboxylato)bis[2‐(pyridin‐4‐yl)‐1H‐benzimidazole]tricadmium(II)

The title compound, [Cd₃(C₈H₁₀O₄)₃(C₁₂H₉N₃)₂(H₂O)₂]_n or [Cd₃(chdc)₃(4‐PyBIm)₂(H₂O)₂]_n, was synthesized hydrothermally from the reaction of Cd(CH₃COO)₂·2H₂O with 2‐(pyridin‐4‐yl)‐1H‐benzimidazole (4‐PyBIm) and cyclohexane‐1,4‐dicarboxylic acid (1,4‐chdcH₂). The asymmetric unit consists of one and a half Cd^II cations, one 4‐PyBIm ligand, one and a half 1,4‐chdc²⁻ ligands and one coordinated water molecule. The central Cd^II cation, located on an inversion centre, is coordinated by six carboxylate O atoms from six 1,4‐chdc²⁻ ligands to complete an elongated octahedral coordination geometry. The two terminal rotationally symmetric Cd^II cations each exhibits a distorted pentagonal–bipyramidal geometry, coordinated by one N atom from 4‐PyBIm, five O atoms from three 1,4‐chdc²⁻ ligands and one O atom from an aqua ligand. The 1,4‐chdc²⁻ ligands possess two conformations, i.e.e,e‐trans‐chdc²⁻ and e,a‐cis‐chdc²⁻. The cis‐1,4‐chdc²⁻ ligands bridge the Cd^II cations to form a trinuclear {Cd₃}‐based chain along the b axis, while the trans‐1,4‐chdc²⁻ ligands further link adjacent one‐dimensional chains to construct an interesting two‐dimensional network.     

Poly[(μ4‐2,5‐dimethoxybenzene‐1,4‐dicarboxylato)manganese(II)] and its zinc(II) analogue: three‐dimensional coordination polymers containing unusually coordinated metal centres

The title compounds, [Mn(C₁₀H₈O₆)]_n and [Zn(C₁₀H₈O₆)]_n, are isomorphous coordination polymers prepared from 2,5‐dimethoxyterephthalic acid (H₂dmt) and the respective metal(II) salts. Both complexes form three‐dimensional metal–organic frameworks with each M^II centre bridged by four 2,5‐dimethoxyterephthalate (dmt²⁻) anions, resulting in the same type of network topology. The asymmetric unit consists of one M^II cation on a twofold axis and one half of a dmt²⁻ anion (located on a centre of inversion). In the crystal structure, the M^II centres are coordinated in a rather unusual way, as there is a distorted tetrahedral inner coordination sphere formed by four carboxylate O atoms of four different dmt²⁻ anions, and an additional outer coordination sphere formed by two methoxy and two carboxylate O atoms, with each of the O atoms belonging to one of the four different dmt²⁻ anions forming the inner coordination sphere. Consideration of both coordination spheres results in a super‐dodecahedral coordination geometry for the M^II centres. Besides the numerous M^II...O interactions, both structures are further stabilized by weak C—H...O contacts.     

Poly[bis(μ‐5‐iodoisophthalato)(methanol)dilead(II)] exhibiting a novel centrosymmetric rhombus‐shaped I4 unit

The asymmetric unit of the title compound, [Pb₂(C₈H₃IO₄)₂(CH₄O)]_n, contains two Pb^II atoms, two 5‐iodoisophthalate (5‐IIP²⁻) ligands and one coordinated methanol molecule. One Pb atom is eight‐coordinated, surrounded by seven carboxylate O atoms from five 5‐IIP²⁻ ligands and one O atom from the terminal methanol ligand. The other Pb atom is seven‐coordinated in a hemidirected geometry, surrounded by seven carboxylate O atoms from five 5‐IIP²⁻ ligands. Both Pb atoms are connected by carboxylate groups to form a one‐dimensional infinite rod along the a axis; neighbouring rods are further linked by the aromatic rings of 5‐IIP²⁻ to generate the final three‐dimensional structure with channels in the a direction. An O—H...O hydrogen bond between the methanol ligand and one of the carboxylate groups of a 5‐IIP²⁻ ligand stablizes the three‐dimensional framework. Interestingly, a centrosymmetric rhombus‐shaped I₄ unit is formed by four 5‐IIP²⁻ ligands, with I...I distances of 3.8841 (8) and 3.9204 (8) Å.     

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.     

The two‐dimensional coordination polymer poly[diaqua(μ2‐1H‐imidazo[4,5‐f][1,10]phenanthroline)‐μ4‐sulfato‐μ3‐sulfato‐dicadmium(II)]

In the title coordination polymer, [Cd₂(SO₄)₂(C₁₃H₈N₄)(H₂O)₂]_n, there are two crystallographically independent Cd^II centres with different coordination geometries. The first Cd^II centre is hexacoordinated by four O atoms of four sulfate ligands, one water O atom and one N atom of a 1H‐imidazo[4,5‐f][1,10]phenanthroline (IP) ligand, giving a distorted octahedral coordination environment. The second Cd^II centre is heptacoordinated by four O atoms of three sulfate ligands, one water O atom and two N atoms of one chelating IP ligand, resulting in a distorted monocapped anti‐trigonal prismatic geometry. The symmetry‐independent Cd^II ions are bridged in an alternating fashion by sulfate ligands, forming one‐dimensional ladder‐like chains which are connected through the IP ligands to form two‐dimensional layers. These two‐dimensional layers are linked by interlayer hydrogen bonds, leading to the formation of a three‐dimensional supramolecular network.