A novel alkaline earth strontium(II) coordination polymer: poly[hexaaquatetrakis(μ5‐pyridine‐2,6‐dicarboxylato)bis(μ4‐pyridine‐2,6‐dicarboxylato)(μ7‐sulfato)heptastrontium(II)]

The title compound, [Sr₇(C₇H₃NO₄)₆(SO₄)(H₂O)₆]_n, has been synthesized by an ionothermal method using the ionic liquid 1‐ethyl‐3‐methylimidazolium ([Emim]Br) as solvent, and characterized by elemental analysis, energy‐dispersive X‐ray spectroscopy, IR and single‐crystal X‐ray diffraction. The structure of the compound can be viewed as a three‐dimensional coordination polymer composed of Sr²⁺ cations, pyridine‐2,6‐dicarboxylate anions, sulfate anions and water molecules. The compound not only exhibits a three‐dimensional structure with a unique coordination mode of the sulfate anion, but also features the first example of a heptanuclear strontium(II) coordination polymer. The structure is further stabilized by O—H...O hydrogen bonds and π–π stacking interactions.     

Two New Solvent‐modulated Zinc(II) Metal‐Organic Hybrid Materials based on Rigid Tripodal Carboxylate Ligand and 2,2′‐Bipy Co‐ligand: Crystal Structures and Luminescent Properties

The zinc(II) coordination polymers [Zn(Htatb)(2,2′‐bipy) · (NMP) · H₂O] ( 1 ) and [Zn₃(tatb)₂(2,2′‐bipy)₃ · H₂O] ( 2 ) (H₃tatb = 4,4′,4′′‐s‐triazine‐2,4,6‐triyl‐tribenzoic acid; 2,2′‐bipy = 2,2′‐bipyridyl, NMP = N‐methyl‐2‐pyrrolidon), were synthesized hydrothermally, and characterized by infrared spectroscopy (IR), powder X‐ray diffraction (PXRD), and single‐crystal X‐ray diffraction. Both compounds 1 and 2 possess expectant low dimensional coordination structures, which further connected into interesting 3D networks by hydrogen bond and strong π–π interactions. Moreover, the thermal stabilities and fluorescent properties of 1 and 2 were investigated.     

Three Coordination Polymers based on 3,5‐Bis(imidazole‐1‐yl)pyridine and Benzoic Acid: Synthesis,Crystal Structures and Photoluminescent Properties

Three metal coordination polymers {[Co(L)₂(H₂O)₂]²⁺ · 2NO₃^–}_n ( 1 ), {[Mn(L)₂(H₂O)₂]²⁺ · 2Cl^– · 3H₂O}_n ( 2 ), and [ZnL(ba)₂]_n ( 3 ) [L = 3,5‐bis(imidazole‐1‐yl)pyridine and Hba = benzoic acid] were synthesized and structurally characterized by IR spectroscopy, elemental analysis, X‐ray powder diffraction, and X‐ray single crystal diffraction. Complex 1 shows a one‐dimensional (1D) chain structure. Adjacent chains are connected by hydrogen bonding and nitrate groups to form a 3D network. Complex 2 features a 2D layer structure. A three‐dimensional network is constructed through the cluster consisting of two chloride ions and three water molecules. Complex 3 shows a 1D zigzag chain structure that further twists together to form a 3D network. The X‐ray powder diffraction patterns were compared with the simulated ones. Moreover, the luminescent properties of 1 – 3 were investigated in the solid state at room temperature, and the thermogravimetric analyses were carried out to study the thermal stability of the three complexes.     

Coordination Frameworks based on 3,5‐Bis(imidazole‐1‐yl)­pyridine and Aromatic Dicarboxylate Ligands: Synthesis,Crystal Structures,and Photoluminescent Properties

Three metal coordination polymers [Zn(bdc)(L)(H₂O)]_n ( 1 ), [Co(pta)(L)(H₂O)₂]_n ( 2 ), and [Cd(tda)(L)(H₂O)]_n ( 3 ) [H₂bdc = 1,2‐benzene dicarboxylate acid, H₂pta = terephthalic acid, H₂tda = 2,5‐thiophenedicarboxylic acid, L = 3,5‐bis(imidazole‐1‐yl)pyridine] were synthesized and structurally characterized by IR spectroscopy, elemental analysis, X‐ray powder diffraction, and X‐ray single crystal diffraction. Complex 1 shows a three‐dimensional (3D) structure with cco topology with the symbol 6⁵ · 8, whereas complex 2 features a 3D structure with cds topology with the symbol 6⁵ · 8. Complex 3 has a 2D network constructed by the cadmium atoms bridged through the ligands tda and L. Their X‐ray powder diffraction patterns were compared with the simulated ones. Moreover, their luminescent properties were investigated in the solid state at room temperature, and the thermogravimetric analyses were carried out to study the thermal stability of the 3D networks.     

Construction and photoluminescence properties of a three‐dimensional ZnII coordination network based on naphthalene‐1,4‐dicarboxylic acid and 1,6‐bis(pyridin‐3‐yl)‐1,3,5‐hexatriene

In recent years, coordination polymers constructed from multidentate carboxylate and pyridyl ligands have attracted much attention because these ligands can adopt a rich variety of coordination modes and thus lead to the formation of crystalline products with intriguing structures and interesting properties. A new coordination polymer, namely poly[[μ₂‐1,6‐bis(pyridin‐3‐yl)‐1,3,5‐hexatriene‐κ²N:N′](μ₃‐naphthalene‐1,4‐dicarboxylato‐κ⁴O¹,O^1′:O⁴:O^4′)zinc(II)], [Zn(C₁₂H₆O₄)(C₁₆H₁₄N₂)]_n, has been prepared by the self‐assembly of Zn(NO₃)₂·6H₂O, naphthalene‐1,4‐dicarboxylic acid (1,4‐H₂ndc) and 1,6‐bis(pyridin‐3‐yl)‐1,3,5‐hexatriene (3,3′‐bphte) under hydrothermal conditions. The title compound has been structurally characterized by IR spectroscopy, elemental analysis, powder X‐ray diffraction and single‐crystal X‐ray diffraction analysis. Each Zn^II ion is six‐coordinated by four O atoms from three 1,4‐ndc²⁻ ligands and by two N atoms from two 3,3′‐bphte ligands, forming a distorted octahedral ZnO₄N₂ coordination geometry. Pairs of Zn^II ions are linked by 1,4‐ndc²⁻ ligands, leading to the formation of a two‐dimensional square lattice ( sql ) layer extending in the ab plane. In the crystal, adjacent layers are further connected by 3,3′‐bphte bridges, generating a three‐dimensional architecture. From a topological viewpoint, if each dinuclear zinc unit is considered as a 6‐connected node and the 1,4‐ndc²⁻ and 3,3′‐bphte ligands are regarded as linkers, the structure can be simplified as a unique three‐dimensional 6‐connected framework with the point symbol 4⁴6¹⁰8. The thermal stability and solid‐state photoluminescence properties have also been investigated.     

A New Coordination Polymer [Pb(1,4‐BDC)]n Containing a Unique μ6‐Bridging Coordination Mode

A new coordination polymer, [Pb(1,4‐BDC)]_n ( 1 ) (1,4‐H₂BDC = 1,4‐benzenedicarboxylic acid), has been synthesized under solvothermal conditions. Its structure was determined with single‐crystal X‐ray diffraction studies and further characterized by inductively coupled plasma (ICP) spectrometry, elemental analysis, IR spectroscopy, thermogravimetric analysis, and X‐ray powder diffraction studies. The results revealed that complex 1 has a two‐dimensional network with (6, 3) topology observed in the [110] direction. Moreover, the layers are connected into a framework through 1,4‐BDC^2? ligands. The μ₆‐bridging coordination mode adopted by 1,4‐BDC^2? is unprecedented in metal/1,4‐BDC^2? complexes.     

Poly[[μ‐(1‐azaniumylethane‐1,1‐diyl)bis(hydrogen phosphonato)]sodium]: a powder X‐ray diffraction study

The title two‐dimensional coordination polymer, [Na(C₂H₈NO₆P₂)]_n, was characterized using powder X‐ray diffraction data and its structure refined using the Rietveld method. The asymmetric unit contains one Na⁺ cation and one (1‐azaniumylethane‐1,1‐diyl)bis(hydrogen phosphonate) anion. The central Na⁺ cation exhibits distorted octahedral coordination geometry involving two deprotonated O atoms, two hydroxy O atoms and two double‐bonded O atoms of the bisphosphonate anion. Pairs of sodium‐centred octahedra share edges and the pairs are in turn connected to each other by the biphosphonate anion to form a two‐dimensional network parallel to the (001) plane. The polymeric layers are connected by strong O—H...O hydrogen bonding between the hydroxy group and one of the free O atoms of the bisphosphonate anion to generate a three‐dimensional network. Further stabilization of the crystal structure is achived by N—H...O and O—H...O hydrogen bonding.<!?tpb=18.7pt>     

Synthesis,Crystal Structure,and Physical Properties of a Barium(II) p‐(Carboxyl‐methyloxy)‐benzenecarboxylic Acid Complex

A coordination polymer [Ba(pcmb)(H₂O)_2.5] ( 1 ) was obtained by self‐assembly of the corresponding metal carbonate with a flexible ligand, p‐(carboxyl‐methyloxy)‐benzenecarboxylic acid (H₂pcmb), and its structure was determined by single‐crystal X‐ray diffraction studies. The result revealed that complex 1 has a three‐dimensional structure, in which the barium(II) atom takes a distorted eight‐coordinate bicapped anti‐prism arrangement. The pcmb^2– anion acts as a μ₄‐bridge ligand, in which carboxylate groups adopt monodentate and μ₃‐η²:η¹‐bridging two different coordination models to generate a three‐dimensional network structure. The luminescence property and thermal stability of 1 were investigated.     

Three Transition Metal(II) Coordination Polymers Constructed by a Semi‐rigid Bis‐pyridyl‐bis‐amide and Dicarboxylates Mixed Ligands: Assembly,Structures and Properties

Three coordination polymers, namely [Co(BDC)( L )] · H₂O ( 1 ), [Co(NPH)( L )] · H₂O ( 2 ), and [Ni(NPH)( L )(H₂O)₃] · H₂O ( 3 ) [H₂BDC = 1, 3‐benzenedicarboxylic acid, H₂NPH = 3‐nitrophthalic acid, L = N,N′‐bis(3‐pyridyl)‐terephthalamide] were hydrothermally synthesized by self‐assembly of cobalt/nickel chloride with a semi‐rigid bis‐pyridyl‐bis‐amide ligand and two aromatic dicarboxylic acids. Single crystal X‐ray diffraction analyses revealed that complexes 1 and 2 are two‐dimensional (2D) coordination polymers containing a one‐dimensional (1D) ribbon‐like Co‐dicarboxylate chain and a 1D zigzag Co‐ L chain. Although the coordination numbers of Co^II ions and the coordination modes of two dicarboxylates are different in complexes 1 and 2 , they have a similar 3, 5‐connected {4².6⁷.8}{4².6} topology. In complex 3 , the adjacent Ni^II ions are linked by L ligands to form a 1D polymeric chain, whereas the 1D chains does not extend into a higher‐dimensional structure due to the ligand NPH with monodentate coordination mode. The adjacent layers of complexes 1 and 2 and the adjacent chains of 3 are further linked by hydrogen bonding interactions to form 3D supramolecular networks. Moreover, the thermal stabilities, fluorescent properties, and photocatalytic activities of complexes 1 – 3 were studied.     

A three‐dimensional CdII coordination framework: poly[di‐μ2‐aqua‐{μ2‐1,4‐bis[(1H‐1,2,4‐triazol‐1‐yl)methyl]benzene‐κ2N4:N4′}di‐μ3‐terephthalato‐κ3O:O′:O′′‐dicadmium(II)]

The title Cd^II coordination polymer, [Cd(C₁₀H₈O₄)(C₁₂H₁₂N₆)_0.5(H₂O)]_n, has been obtained by the hydrothermal method and studied by single‐crystal X‐ray diffraction, elemental analysis, thermogravimetric analysis, IR spectroscopy and fluorescence spectroscopy. The compound forms a novel three‐dimensional framework with 3,8‐connected three‐dimensional binodal {4.5²}₂{4².5¹⁰.6¹².7.8³} topology. An investigation of its photoluminescence properties shows that the compound exhibits a strong fluorescence emission in the solid state at room temperature.     

Hydrothermal Syntheses and Crystal Structures of Two New Three‐dimensional Coordination Polymers Based on 4‐Pyrid‐3‐ylbenzoic Acid

Two new coordination polymers [Co₂(pbc)₄(H₂O)]_n ( 1 ) and [Mn(pbc)₂] ( 2 ) (Hpbc = 4‐pyrid‐3‐ylbenzoic acid) were obtained by hydrothermal reaction and characterized by elemental analysis, IR spectroscopy, and single‐crystal X‐ray diffraction. Compound 1 features a 3D network with a four‐connected 6⁶ net constructed from secondary building units of dinuclear cobalt. Compound 2 exhibits a six‐connected 4¹² · 6³ topology based on dinuclear manganese.     

A 4′‐(4‐carboxyphenyl)‐3,2′:6′,3′′‐terpyridine‐based luminescent cadmium(II) coordination polymer for the detection of 2,4,6‐trinitrophenol

The title coordination polymer, poly[bis[μ3‐4‐(3,2′:6′,3′′‐terpyridin‐4′‐yl)benzoato]cadmium(II)], [Cd(C₂₂H₁₄N₃O₂)₂]_n or [Cd(3‐cptpy)₂]_n, (I), has been synthesized solvothermally and characterized by IR spectroscopy, thermogravimetric analysis, and single‐crystal and powder X‐ray diffraction. The structure is composed of 3‐cptpy^? ligands bridging Cd atoms, with each Cd atom coordinated by six ligands and each ligand coordinating to three Cd atoms. Each Cd atom is in a slightly distorted trans‐N₂O₄ octahedral environment, forming a two‐dimensional layer structure with a (3,6)‐connected topology. Layers are linked to each other by π–π stacking, resulting in a three‐dimensional supramolecular framework. The strong luminescence and good thermal stability of (I) indicate that it can potentially be used as a luminescence sensor. The compound also shows a highly selective and sensitive response to 2,4,6‐trinitrophenol through the luminescence quenching effect.     

A 3D Nickel(II) Coordination Polymer with cds Nets Constructed from 3‐Pyridin‐4‐yl‐benzoic Acid

A new coordination polymer, [Ni(3,4‐pybz)₂(H₂O)]_n ( 1 ), was hydrothermally synthesized from Ni(NO₃)₂ · 6H₂O and an unsymmetrical 3‐pyridin‐4‐yl‐benzoic acid (3,4‐Hpybz). It was characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis, and single‐crystal X‐ray diffraction. In complex 1 , the 3,4‐pybz ligands act as linear linkers to join 4‐connected nickel(II) ion nodes, to build a 3D 4‐connected twofold interpenetrated 6⁵8‐cds coordination framework. In addition, the magnetic and thermal properties of complex 1 were also investigated.     

A novel dinuclear bismuth(III) coordination compound: bis(μ‐pyridine‐2,6‐dicarboxylato)‐κ4O2,N,O6:O6′;κ4O2:O2′,N,O6‐bis[(azido‐κN)(1,10‐phenanthroline‐κ2N,N′)bismuth(III)] tetrahydrate

A novel dinuclear bismuth(III) coordination compound, [Bi₂(C₇H₃NO₄)₂(N₃)₂(C₁₂H₈N₂)₂]·4H₂O, has been synthesized by an ionothermal method and characterized by elemental analysis, energy‐dispersive X‐ray spectroscopy, IR, X‐ray photoelectron spectroscopy and single‐crystal X‐ray diffraction. The molecular structure consists of one centrosymmetric dinuclear neutral fragment and four water molecules. Within the dinuclear fragment, each Bi^III centre is seven‐coordinated by three O atoms and four N atoms. The coordination geometry of each Bi^III atom is distorted pentagonal–bipyramidal (BiO₃N₄), with one azide N atom and one bridging carboxylate O atom located in axial positions. The carboxylate O atoms and water molecules are assembled via O—H...O hydrogen bonds, resulting in the formation of a three‐dimensional supramolecular structure. Two types of π–π stacking interactions are found, with centroid‐to‐centroid distances of 3.461 (4) and 3.641 (4) Å.     

A twofold interpenetrating three‐dimensional CdII coordination framework: poly[[μ2‐1,3‐bis(2‐methyl‐1H‐imidazol‐1‐yl)benzene](μ3‐5‐nitrobenzene‐1,3‐dicarboxylato)cadmium(II)]

A twofold interpenetrating three‐dimensional Cd^II coordination framework, [Cd(C₈H₃NO₆)(C₁₄H₁₄N₄)]_n, has been prepared and characterized by IR spectroscopy, elemental analysis, thermal analysis and single‐crystal X‐ray diffraction. The asymmetric unit consists of a divalent Cd^II atom, one 1,3‐bis(2‐methyl‐1H‐imidazol‐1‐yl)benzene (1,3‐BMIB) ligand and one fully deprotonated 5‐nitrobenzene‐1,3‐dicarboxylate (NO₂‐BDC²⁻) ligand. The coordination sphere of the Cd^II atom consists of five O‐donor atoms from three different NO₂‐BDC²⁻ ligands and two imidazole N‐donor atoms from two different 1,3‐BMIB ligands, forming a distorted {CdN₂O₅} pentagonal bipyramid. The NO₂‐BDC ligand links three Cd^II atoms via a μ₁‐η¹:η¹ chelating mode and a μ₂‐η²:η¹ bridging mode. The title compound is a twofold interpenetrating 3,5‐connected network with the {4².6⁵.8³}{4².6} topology. In addition, the compound exhibits fluorescence emissions in the solid state at room temperature.     

A new two‐dimensional ZnII coordination polymer based on 1,3‐bis(2‐methyl‐1H‐imidazol‐1‐yl)benzene and 5‐nitrobenzene‐1,3‐dicarboxylic acid: synthesis,crystal structure and physical properties

A novel two‐dimensional (2D) Zn^II coordination framework, poly[[μ‐1,3‐bis(2‐methyl‐1H‐imidazol‐1‐yl)benzene](μ‐5‐nitrobenzene‐1,3‐dicarboxylato)zinc(II)], [Zn(C₈H₃NO₆)(C₁₄H₁₄N₄)]_n or [Zn(NO₂‐BDC)(1,3‐BMIB)]_n [1,3‐BMIB is 1,3‐bis(2‐methyl‐1H‐imidazol‐1‐yl)benzene and NO₂‐H₂BDC is 5‐nitrobenzene‐1,3‐dicarboxylic acid], has been prepared and characterized by IR, elemental analysis, thermal analysis and single‐crystal X‐ray diffraction. Single‐crystal X‐ray diffraction analysis revealed that the compound is a new 2D polymer with a 6³ topology parallel to the (10) crystal planes based on left‐handed helices, right‐handed helical NO₂‐BDC–Zn chains and [Zn₂(1,3‐BMIB)₂]_n clusters. In the crystal, adjacent layers are further connected by C—H…O hydrogen bonds, C—H…π interactions, C—O…π interactions and N—O…π interactions to form a three‐dimensional structure in the solid state. In addition, the compound exhibits strong fluorescence emissions in the solid state at room temperature.     

Synthesis,Crystal Structure,and Physical Properties of a ­Barium(II) Benzene‐1, 2, 3‐tricarboxylic Acid Complex

A coordination polymer [Ba₁₂(btc)₈(H₂O)₂₃] ( 1 ) was obtained by self‐assembly of the corresponding metal carbonate with benzene‐1, 2, 3‐tricarboxylic acid ligand (H₃btc), and its structure was determined by single‐crystal X‐ray diffraction studies. The results revealed that complex 1 has a three dimensional structure. In 1 , the btc^3– anions adopt four different conformation and coordination modes. Bridging btc^3– anions and μ₂‐bridging water molecules connect Ba^II ions to generate a two dimensional layer. Further, μ₂‐bridging coordinated water molecules connect the Ba^II ions of neighboring layers to form a three dimensional structure. Additionally, the luminescent property and thermal stability of 1 were investigated.     

A three‐dimensional cadmium coordination polymer based on 1,4‐bis(1,2,4‐triazol‐1‐yl)but‐2‐ene and benzene‐1,3,5‐tricarboxylic acid

The Cd^II three‐dimensional coordination poly[[[μ₄‐1,4‐bis(1,2,4‐triazol‐1‐yl)but‐2‐ene]bis(μ₃‐5‐carboxybenzene‐1,3‐dicarboxylato)dicadmium(II)] dihydrate], {[Cd₂(C₉H₄O₆)₂(C₈H₁₀N₆)]·2H₂O}_n , (I), has been synthesized by the hydrothermal reaction of Cd(NO₃)₂·4H₂O, benzene‐1,3,5‐tricarboxylic acid (1,3,5‐H₃BTC) and 1,4‐bis(1,2,4‐triazol‐1‐yl)but‐2‐ene (1,4‐btbe). The IR spectrum suggests the presence of protonated carboxylic acid, deprotonated carboxylate and triazolyl groups. The purity of the bulk sample was confirmed by elemental analysis and X‐ray powder diffraction. Single‐crystal X‐ray diffraction analysis reveals that the Cd^II ions adopt a five‐coordinated distorted trigonal–bipyramidal geometry, coordinated by three O atoms from three different 1,3,5‐HBTC²⁻ ligands and two N atoms from two different 1,4‐btbe ligands; the latter are situated on centres of inversion. The Cd^II centres are bridged by 1,3,5‐HBTC²⁻ and 1,4‐btbe ligands into an overall three‐dimensional framework. When the Cd^II centres and the tetradentate 1,4‐btbe ligands are regarded as nodes, the three‐dimensional topology can be simplified as a binodal 4,6‐connected network. Thermogravimetric analysis confirms the presence of lattice water in (I). Photoluminescence studies imply that the emission of (I) may be ascribed to intraligand fluorescence.     

A two‐dimensional coordination polymer: poly[diaqua(μ4‐4,4′‐oxydibenzoato)(μ2‐4,4′‐oxydibenzoato)dilead(II)]

In a new two‐dimensional coordination polymer, [Pb(C₁₄H₈O₅)(H₂O)]_n, the asymmetric unit consists of a Pb^II cation, two halves of two crystallographically distinct fully deprotonated 4,4′‐oxydibenzoate ligands and one aqua ligand. Single‐crystal X‐ray diffraction analysis reveals that the compound is a coordination polymer with the point symbol {5³}₂{5⁴.8²}. In addition, it exhibits a strong fluorescence emission in the solid state at room temperature.     

Synthesis and Characterization of a Zinc(II) Complex with Mixed 4‐Hydroxypyridine‐2,6‐dicarboxylic Acid and 1,3‐Bis(4‐pyridyl)propane Tectons

The metal‐organic framework {[Zn₂(CAM)(μ₂‐OH)(bpp)] · 2H₂O}_n ( 1 ) [H₃CAM = 4‐hydroxypyridine‐2,6‐dicarboxylic acid, bpp = 1,3‐bis(4‐pyridyl)propane], was hydrothermally synthesized and characterized by elemental analyses, infrared spectroscopy, and single‐crystal X‐ray diffraction. Compound 1 presents a three dimensional self‐penetrating 8‐connected framework with the Schläfli symbol 4²⁰.5³.6⁵. In addition, the fluorescent properties and thermal stability of 1 were discussed as well.