Recombination of Coordination Bonds of a Mononuclear Precursor into a 3D d‐d′ Heterometallic Coordination Polymer with Double Helices

Abstract. Based on a mononuclear precursor [Mn(Hstp)₂(4,4′‐Hbpy)₂] ( 1 ), a hetero‐metallic complex, [Mn₂Ni(stp)₂(4,4′‐bpy)(H₂O)₄] ( 2 ) [stp = 2‐sulfoterephthalate, 4,4′‐bpy = 4,4′‐bpyridine] was synthesized by solvothermal reaction. Single‐crystal X‐ray diffraction analysis reveals that the Mn^II ion of the precursor 1 is hexacoordinate by four oxygen atoms from two Hstp^2– anions and two nitrogen atoms from two protonated 4, 4′‐Hbpy, and hydrogen bonding plays a significant role in constructing 3D supramolecular structure. While complex 2 features a self‐weaving framework from 1D straight chains and 2D wavy networks with double helical chains. Magnetic behavior of complex 2 was analyzed in connection with its crystal structure, which exhibits the weak antiferromagnetic interactions between the Mn^II and Ni^II ions.     

Synthesis and crystal structure of heteronuclear La( III )‐Cu(II ) complex { [LaCu2(NTA)2(4,4′‐bpy)(H2O)3]NO3·5H2O}n

A novel La( III )‐Cu( II ) heterometallic coordination polymer {[LaCu₂(NTA)₂(4,4′‐bpy)(H₂O)₃]NO₃·5H₂O]_n, where H₃NTA denotes nitrilotriacetic acid and 4,4′‐bpy denotes 4, 4‐bipyridine, was synthesized and characterized by IR spectrum, elemental analysis and X‐ray diffraction. The complex crystallizes in the triclinic space group Pi with cell parameters a = 1.33710(10) nm, b = 1,44530(10) nm, c =1.0949(2) nm, α = 71.905(7)°, β = 74.327(7)°, γ = 64.427(9)°, V = 1.7912(4) nm³and Z = 2. It consists of heterometallic units, in which each La( II ) ion is coordinated in a distorted monocapped square antiprism by three oxygen atoms from water molecules and six carboxyl oxygen atoms from five NTA^3? ions, and each Cu( I ) ion is coordinated by one nitrogen atom from 4,4′‐bpy and one nitrogen atom, three oxygen atoms from NTA^3?. In the title complex, La( I ) ions and Cu( II ) ions are connected by the heterometallic bridging of NTA^3?, constructing a two‐dimensional network structure along the [110]. And it is extended into an infinite three‐dimensional network structure by the formation of homometallic bridging of Cu‐4, 4′‐bpy‐Cu, exhibiting a certain inclusion ability.     

Syntheses,Crystal Structures,and Fluorescence Properties of Two Transition Metal‐Organic Coordination Polymers Based on 4,4′‐Dimethyl‐2,2′‐bipyridine

Two transition metal‐organic coordination polymers, [Mn₂(1,3‐bdc)₂(Me₂bpy)₂] · Me₂bpy ( 1 ) and [Co(4,4′‐oba)(Me₂bpy)] ( 2 ) were hydrothermally synthesized and structurally characterized by elemental analysis, IR spectroscopy, TG, and single‐crystal X‐ray diffraction [1,3‐H₂bdc = benzene‐1,3‐dicarboxylic acid, H₂oba = 4,4′‐oxybis(benzoic acid) Me₂bpy = 4,4′‐dimethyl‐2,2′‐bipyridine]. Compound 1 crystallizes in the orthorhombic system, space group P2₁2₁2₁, with a = 23.371(5), b = 14.419(3), and c = 14.251(3) Å. Compound 2 crystallizes in the monoclinic system, space group P2₁/c, with a = 7.4863(15), b = 18.272(4), c = 16.953(5) Å, and β = 107.44(3)°. The crystal structure of complex 1 is a wave‐like layer with central Mn²⁺ atoms bridged by 1,3‐bdc ligands, whereas the structure of compound 2 presents a ladder chain of hexacoordinate Co²⁺ atoms, in which the metal atoms are bridged by 4,4′‐oba ligands and decorated by Me₂bpy ligands. The two compounds are further extended into 3D supramolecular structures through π–π stacking interactions. Additionally, the compounds show intense fluorescence in solid state at room temperature.     

Modular Construction,Structures, and Magnetic Properties of Two Manganese Coordination Polymers Based on 3,5‐Bis(2–carboxylphenoxy)benzoic Acid

Two manganese(II) coordination polymers, namely, [Mn_1.5(BCB)(bpy)_1.5(H₂O)]_n ( 1 ), and [Mn(HBCB)(bibp)₂(H₂O)] ( 2 ), were assembled from the mixed ligands of the flexible tripodal ligand of 3,5‐bis(2‐carboxylphenoxy)benzoic acid (H₃BCB) and two rigid N‐donors [bpy = 4,4′‐bipyridine, and bibp = 4,4′‐bis(imidazolyl)biphenyl]. Their structures were determined by single‐crystal X‐ray diffraction analyses and further characterized by elemental analyses (EA), IR spectra, powder X‐ray diffraction (PXRD), and thermogravimetric (TG) analyses. Structural analysis reveals that complex 1 is a 3D (3,4,6)‐connected {5 · 6²}₂{5⁶ · 6⁴ · 7 · 8² · 9²}{6⁴ · 8 · 9} net based on two kinds of inorganic nodes of dinuclear {Mn₂(COO)₂} SBUs and Mn(2) ions. Complex 2 is a hydrogen bonds based 3D supramolecule with 6‐connected {4¹² · 6³}‐ pcu net. Besides, the variable‐temperature susceptibilities of 1 and 2 were investigated.     

Poly[diaqua­(μ‐4,4′‐bipyridine)tetra­kis­(μ‐ferro­cenecarboxyl­ato)bis­(ferro­cenecarboxyl­ato)­tri­man­ganese(II)]

The title compound, [Mn₃Fe₆(C₅H₅)₆(C₆H₄O₂)₆(C₁₀H₈N₂)(H₂O)₂]_n, consists of two crystallographically unique Mn^II centers. One is situated on an inversion center and is octa­hedrally coordinated by two N atoms from two bridging 4,4′‐bipyridine (4,4′‐bipy) ligands and four O atoms, two from different bridging ferrocenecarboxyl­ate (μ₂‐FcCOO⁻; Fc is ferrocene) units and two from aqua ligands. The two halves of each 4,4′‐bipy ligand are related by a center of symmetry. The second Mn^II center is in a strongly distorted tetra­gonal–pyramidal geometry, coordinated by five O atoms, three from three μ₂‐FcCOO⁻ units and two from a fourth, chelating, η²‐FcCOO⁻ unit. The FcCOO⁻ units function as bridging ligands to adjacent Mn^II centers, leading to the formation of linear ⋯Mn1Mn2Mn2Mn1⋯ chains. Adjacent chains are further bridged by 4,4′‐bipy ligands, resulting in a two‐dimensional layered polymer.     

Diverse Coordinative Functions of 4,4′‐Bipyridine Generating Abundant Weak Interactions and Novel Fluorescent Property in Cadmium(II)‐4‐sulfobenzoate Polymer

The cadmium(II) 4‐sulfobenzoate complex with 4,4′‐bipyridine, {[Cd₂(4,4′‐bipy)₄(4‐sb)₂(H₂O)₃] · 4H₂O}_n, has been synthesized and characterized by elemental analysis, IR, DTA‐TG, fluorescence analysis, powder X‐ray analysis, and single‐crystal X‐ray structural determination. Structural analysis showed that the complex contains two Cd atoms in an unsymmetrical unit. The Cd1 atom displays a seven‐coordinated geometry, which is a capped anti‐trigonal prismatic structure, whereas the Cd2 atom has an octahedral coordination. The 4,4′‐bipyridine ligands in the complex have three coordination behaviors, i.e., monodentate, dimeric linker, and polymeric bridge, which is the first example showing three coordinative functions for 4,4′‐bipyridine ligands in one complex. Moreover, three coordinative functions of 4,4′‐bipyridine ligands in this polymer lead to abundant weak interactions and novel fluorescent properties, which is benefit for design and preparation of functional materials in specific usage.     

A novel one‐dimensional complex: catena‐poly­[[manganese(III)‐di‐μ‐2‐[(2‐hydroxy­ethyl)­imino­methyl]­phenolato‐κ2O1,N:κO2;κO2:κ2O1] chloride]

In the title one‐dimensional complex, {[Mn^III(C₉H₁₀NO₂)₂]Cl}_n, the Schiff base ligand 2‐[(2‐hydroxy­ethyl)­imino­methyl]­phenolate (Hsae⁻) functions as both a bridging and a chelating ligand. The Mn^III ion is six‐coordinated by two N and four O atoms from four different Hsae⁻ ligands, yielding a distorted MnO₄N₂ octahedral environment. Each [Mn^III(Hsae)₂]⁺ cationic unit has the Mn atom on an inversion centre and each [Mn^III(Hsae)₂]⁺ cation lies about another inversion centre. The chain‐like complex is further extended into a three‐dimensional network structure through Cl⋯H—O hydrogen bonds and C—H⋯π contacts involving the Hsae⁻ rings.     

A novel two‐dimensional MnII coordination polymer with 1,2‐bis­(imidazol‐1‐yl)­ethane

In the crystal structure of the title complex, poly­[[di­azido­manganese(II)]‐di‐μ‐1,2‐bis­(imidazol‐1‐yl)­ethane‐κ⁴N³:N^3′], [Mn(N₃)₂(C₈H₁₀N₄)₂]_n or [Mn(N₃)₂(bim)₂]_n, where bim is 1,2‐­bis(imidazol‐1‐yl)­ethane, each Mn^II atom is six‐coordinated in a distorted octahedral coordination environment to four N atoms from four bim ligands and two N atoms from two azide ligands. The Mn^II atoms, which lie on inversion centres, are bridged by four bim ligands to form a two‐dimensional (4,4)‐network. The azide ligands are monodentate (terminal).     

X‐ray characterization and magnetic properties of dioxygen‐bridged CuII and MnIII Schiff base complexes

The coordination chemistry of multinuclear metal compounds is important because of their relevance to the multi‐metal active sites of various metalloproteins and metalloenzymes. Multinuclear Cu^II and Mn^III compounds are of interest due to their various properties in the fields of coordination chemistry, inorganic biochemistry, catalysis, and optical and magnetic materials. Oxygen‐bridged binuclear Mn^III complexes generally exhibit antiferromagnetic interactions and a few examples of ferromagnetic interactions have also been reported. Binuclear Cu^II complexes are important due to the fact that they provide examples of the simplest case of magnetic interaction involving only two unpaired electrons. Two novel dioxygen‐bridged copper(II) and manganese(III) Schiff base complexes, namely bis(μ‐4‐bromo‐2‐{[(3‐oxidopropyl)imino]methyl}phenolato)dicopper(II), [Cu₂(C₁₀H₁₀BrNO₂)₂], (1), and bis(diaqua{4,4′‐dichloro‐2,2′‐[(1,1‐dimethylethane‐1,2‐diyl)bis(nitrilomethanylylidene)]diphenolato}manganese(III)) bis{μ‐4,4′‐dichloro‐2,2′‐[(1,1‐dimethylethane‐1,2‐diyl)bis(nitrilomethanylylidene)]diphenolato}bis[aquamanganese(III)] tetrakis(perchlorate) ethanol disolvate, [Mn(C₁₈H₁₆Cl₂N₂O₂)(H₂O)₂]₂[Mn₂(C₁₈H₁₆Cl₂N₂O₂)₂(H₂O)₂](ClO₄)₄·2C₂H₅OH, (2), have been synthesized and single‐crystal X‐ray diffraction has been used to analyze their crystal structures. The structure analyses of (1) and (2) show that each Cu^II atom is four‐coordinated, with long weak Cu…O interactions of 2.8631 (13) Å linking the dinuclear halves of the centrosymmetric tetranucelar molecules, while each Mn^III atom is six‐coordinated. The shortest intra‐ and intermolecular nonbonding Mn…Mn separations are 3.3277 (16) and 5.1763 (19) Å for (2), while the Cu…Cu separations are 3.0237 (3) and 3.4846 (3) Å for (1). The magnetic susceptibilities of (1) and (2) in the solid state were measured in the temperature range 2–300 K and reveal the presence of antiferromagnetic spin‐exchange interactions between the transition metal ions.     

Poly[diaqua(μ‐4,4′‐bipyridine‐κ2N:N′)bis(μ‐cyanido‐κ2C:N)bis(cyanido‐κC)nickel(II)copper(II)]: a metal–organic cyanide‐bridged framework

The structure of the title compound, [NiCu(CN)₄(C₁₀H₈N₂)(H₂O)₂]_n or [{Cu(H₂O)₂}(μ‐C₁₀H₈N₂)(μ‐CN)₂{Ni(CN)₂}]_n, was shown to be a metal–organic cyanide‐bridged framework, composed essentially of –Cu–4,4′‐bpy–Cu–4,4′‐bpy–Cu– chains (4,4′‐bpy is 4,4′‐bipyridine) linked by [Ni(CN)₄]²⁻ anions. Both metal atoms sit on special positions; the Cu^II atom occupies an inversion center, while the Ni^II atom of the cyanometallate sits on a twofold axis. The 4,4′‐bpy ligand is also situated about a center of symmetry, located at the center of the bridging C—C bond. The scientific impact of this structure lies in the unique manner in which the framework is built up. The arrangement of the –Cu–4,4′‐bpy–Cu–4,4′‐bpy–Cu– chains, which are mutually perpendicular and non‐intersecting, creates large channels running parallel to the c axis. Within these channels, the [Ni(CN)₄]²⁻ anions coordinate to successive Cu^II atoms, forming zigzag –Cu—N[triple‐bond]C—Ni—C[triple‐bond]N—Cu– chains. In this manner, a three‐dimensional framework structure is constructed. To the authors' knowledge, this arrangement has not been observed in any of the many copper(II)–4,4′‐bipyridine framework complexes synthesized to date. The coordination environment of the Cu^II atom is completed by two water molecules. The framework is further strengthened by O—H...N hydrogen bonds involving the water molecules and the symmetry‐equivalent nonbridging cyanide N atoms.     

catena‐Poly[[aqua­bis(1H‐benzimidazole‐κN3)manganese(II)]‐μ‐adipato]

In the title polymeric complex, [Mn(C₆H₈O₄)(C₇H₆N₂)₂(H₂O)]_n, the Mn^II atom is surrounded by two adipate dianions, two benzimidazole mol­ecules and one coordinated water mol­ecule. The Mn atoms and coordinated water mol­ecule are located on a twofold axis, and the bridging adipate ligand is located on an inversion center. The adipate dianions bridge neighboring Mn^II atoms to form polymeric chains. Each Mn^II atom is seven‐coordinate, the longest Mn—O bond length being 2.5356 (16) Å.     

Aquachloro[N,N′‐ethylenebis(salicylideneiminato)]manganese(III)

The title compound, aqua­chloro{2,2′‐[1,2‐ethanediyl­bis­(nitrilo­methyl­idyne)]­diphenolato‐κ⁴O,N,N′,O′}manganese(III),[MnCl(C₁₆H₁₄N₂O₂)(H₂O)], is a neutral manganese(III) complex with a pseudo‐octahedral metal centre. The equatorial plane comprises the four donor atoms of the tetradentate Schiff base ligand [Mn—O 1.886 (4) and 1.893 (4) Å, and Mn—N 1.978 (5) and 1.982 (5) Å], with a water mol­ecule [Mn—O 2.383 (4) Å] and a Cl^? ligand [Mn—Cl 2.4680 (16) Å] completing the coordination sphere. The distorted geometry is highlighted by the marked displacement of the Mn^III ion out of the least‐squares plane of the four Schiff base donor atoms by 0.165 (2) Å. These monomeric Mn^III centres are then linked into a polymeric array via hydrogen bonds between the coordinated water mol­ecule and the phenolic O‐atom donors of an adjacent Mn^III centre [O—H?O 2.789 (5) and 2.881 (5) Å].     

Synthesis,Crystal Structure,and Magnetic Properties of a New Coordination Polymer Framework [CoII(4,4′‐bpy)(N3)2]n

A new cobalt(II) coordination polymer containing 4,4′‐bipyridine and azide as bridging ligand, [Co^II(4,4′‐bpy)(N₃)₂]_n ( 1 ) was synthesized under mild hydrothermal conditions and was characterized by single‐crystal X‐ray diffraction studies and magnetic susceptibility measurements. It exhibits an acentric structure, in which cobalt(II) ions are linked through end‐to‐end (EE) azido groups. The 4,4′‐bpy ligands are coordinated on the axial positions of the octahedral environment reinforcing the intermetallic connections and resulting in a network. Circular dichroism spectra of the compound exhibit a maximum negative Cotton effect at 260 nm, which indicates the chiral nature of 1 . Variable temperature magnetic susceptibility measurements in the temperature range 2–300 K reveal the existence of antiferromagnetic couplings in the framework.     

Synthesis and Crystal Structures of Manganese(II) and ­Cobalt(II) Complexes with 2, 6‐Dimethoxybenzoic Acid and Additional N‐Donor Ligands

Three coordination compounds [Mn₃(dmb)₆(H₂O)₄(4, 4′‐bpy)₃(EtOH)]_n ( 1 ) and [M(dmb)₂(pyz)₂ (H₂O)₂] [M^II = Co ( 2 ), Mn ( 3 )] (Hdmb = 2, 6‐dimethoxybenzoic acid, 4, 4′‐bpy = 4, 4′‐bipyridine, pyz = pyrazine) were synthesized and characterized by single‐crystal X‐ray diffraction analysis. Compound 1 consists of infinite 1D polymeric chains, in which the metal entities are bridged by 4, 4′‐bpy ligands. There are four crystallographically independent Mn^II atoms in the linear chain with different coordination modes, which is only scarcely reported for linear polymers. The isostructural crystals of 2 and 3 are composed of neutral mononuclear complexes. In crystal the complexes are combined into chains by intermolecular O–H ··· N hydrogen bonds and π–π interactions between antiparallel pyrazine molecules.     

Synthesis,Crystal Structures,and Photoluminescence of Lanthanide Coordination Polymers with 4‐Acetamidobenzoate

The reactions of Ln(NO₃)₃ · 6H₂O and 4‐acetamidobenzoic acid (Haba) with 4,4′‐bipyridine (4,4′‐bpy) in ethanol solution resulted in three new lanthanide coordination polymers, namely {[Ln(aba)₃(H₂O)₂] · 0.5(4,4′‐bpy) · 2H₂O}_∞ [Ln = Sm ( 1 ), Gd ( 2 ), and Er ( 3 ), aba = 4‐acetamidobenzoate]. Compounds 1 – 3 are isomorphous and have one‐dimensional chains bridged by four aba anions. 4,4′‐Bipyridine molecules don’t take part in the coordination with Ln^III ions and occur in the lattice as guest molecules. Moreover, the adjacent 1D chains in the complex are further linked through numerous N–H ··· O and O–H ··· O hydrogen bonds to form a 3D supramolecular network. In addition, complex 1 in the solid state shows characteristic emission in the visible region at room temperature.     

Oxygen‐Atom Transfer Chemistry and Thermolytic Properties of a Di‐tert‐Butylphosphate‐Ligated Mn4O4 Cubane

[Mn₄O₄{O₂P(OtBu)₂}₆] ( 1 ), an Mn₄O₄ cubane complex combining the structural inspiration of the photosystem II oxygen‐evolving complex with thermolytic precursor ligands, was synthesized and fully characterized. Core oxygen atoms within complex 1 are transferred upon reaction with an oxygen‐atom acceptor (PEt₃), to give the butterfly complex [Mn₄O₂{O₂P(OtBu)₂}₆(OPEt₃)₂]. The cubane structure is restored by reaction of the latter complex with the O‐atom donor PhIO. Complex 1 was investigated as a precursor to inorganic Mn metaphosphate/pyrophosphate materials, which were studied by X‐ray absorption spectroscopy to determine the fate of the Mn₄O₄ unit. Under the conditions employed, thermolyses of 1 result in reduction of the manganese to Mn^II species. Finally, the related butterfly complex [Mn₄O₂{O₂P(pin)}₆(bpy)₂] (pin=pinacolate) is described.     

A cyanide‐bridged FeIII–MnII heterobimetallic one‐dimensional coordination polymer: synthesis,crystal structure,experimental and theoretical magnetism investigation

A new cyanide‐bridged Fe^III–Mn^II heterobimetallic coordination polymer (CP), namely catena‐poly[[[N,N′‐(1,2‐phenylene)bis(pyridine‐2‐carboxamidato)‐κ⁴N,N′,N′′,N′′′]iron(III)]‐μ‐cyanido‐κ²C:N‐[bis(4,4′‐bipyridine‐κN)bis(methanol‐κO)manganese(II)]‐μ‐cyanido‐κ²N:C], {[FeMn(C₁₈H₁₂N₄O₂)(CN)₂(C₁₀H₈N₂)₂(CH₃OH)₂]ClO₄}_n, ( 1 ), was prepared by the self‐assembly of the trans‐dicyanidoiron(III)‐containing building block [Fe(bpb)(CN)₂]^? [bpb^2? = N,N′‐(1,2‐phenylene)bis(pyridine‐2‐carboxamidate)], [Mn(ClO₄)₂]·6H₂O and 4,4′‐bipyridine, and was structurally characterized by elemental analysis, IR spectroscopy, single‐crystal X‐ray crystallography and powder X‐ray diffraction (PXRD). Single‐crystal X‐ray diffraction analysis shows that CP 1 possesses a cationic linear chain structure consisting of alternating cyanide‐bridged Fe–Mn units, with free perchlorate as the charge‐balancing anion, which can be further extended into a two‐dimensional supramolecular sheet structure via inter‐chain π–π interactions between the 4,4′‐bipyridine ligands. Within the chain, each Mn^II ion is six‐coordinated by an N₆ unit and is involved in a slightly distorted octahedral coordination geometry. Investigation of the magnetic properties of 1 reveals an antiferromagnetic coupling between the cyanide‐bridged Fe^III and Mn^II ions. A best fit of the magnetic susceptibility based on the one‐dimensional alternating chain model leads to the magnetic coupling constants J₁ = ?1.35 and J₂ = ?1.05 cm^?1, and the antiferromagnetic coupling was further confirmed by spin Hamiltonian‐based density functional theoretical (DFT) calculations.     

A Series of Transition Metal Coordination Polymers Bearing 1,4‐Phenylenediacetate

The reactions of transition metal salts or hydroxide with 1,4‐phenylenediacetic acid (H₂PDA) in the presence of ancillary ligands 4,4′‐bipyridine (4,4′‐bpy) or imidazole (Im) produced five coordination polymers with the empirical formula [M(PDA)(4,4′‐bpy)(H₂O)₂]_n [M = Mn ( 1 ), Ni ( 2 )], [Cu(PDA)(4,4′‐bpy)]_n · 2nH₂O ( 3 ), [Ni(PDA)(Im)₂(H₂O)₂]_n · nH₂O ( 4 ), and [Cu(PDA)(Im)₂]_n · 2nH₂O ( 5 ). Their structures were determined by single‐crystal X‐ray diffraction analyses. The isomorphous 1 and 2 present a two‐dimensional sheet constructed by two kinds of one‐dimensional chains of –Ni^II–PDA^2––Ni^II– and –Ni^II–4,4′‐bpy–Ni^II–. Compound 3 features dinuclear subunits, which are further connected by two PDA^2– ligands and two 4,4′‐bpy ligands along (001) and (011) directions, respectively, to build a two‐dimensional sheet with the topology (4².6⁷.8)(4².6) different from those of 1 and 2 . Both 4 and 5 show one‐dimensional chain structure. The difference of compound 4 and 5 is that the two carboxylato groups of PDA^2– in 4 adopt monodentate coordination modes, whereas the two carboxylato groups of PDA^2– in 5 chelate to the metal ions. Magnetic susceptibility data of 1 were measured. Magnetically, 1 presents a one‐dimensional chain with a weak antiferromagnetic interaction (J =–0.064 cm^–1) between the intrachain Mn^II atoms mediated by 4,4′‐bpy.     

Poly­[[di­aqua­cobalt(II)]‐μ‐4,4′‐bi­pyridine‐κ2N:N′‐μ‐p‐phenyl­enebis­(oxy­acetato)‐κ2O:O′]

The title compound, [Co^II(C₁₀H₈O₆)(C₁₀H₈N₂)(H₂O)₂]_n, was obtained by the hydro­thermal reaction of CoSO₄ with benzene‐1,4‐dioxy­di­acetate [systematic name: p‐phenyl­ene­bis­(oxy­acetate)] and 4,4′‐bi­pyridine (4,4′‐bpy). The Co atom lies at an inversion center and the benzene‐1,4‐dioxydiacetate and 4,4′‐bipyridine moieties lie about other inversion centers. The benzene‐1,4‐dioxydiacetate ligands bridge the octahedral Co^II coordination centers, forming a one‐dimensional zigzag chain. The chains are further bridged by 4,4′‐bpy ligands, forming a novel two‐dimensional supramolecular architecture. Hydro­gen‐bonding interactions between the coordinated water mol­ecules and the carboxyl­ate O atoms lead to the formation of a three‐dimensional network structure.     

A novel cadmium(II) coordination polymer with biphenyl‐3,3′,4,4′‐tetra­carboxylic acid and 4,4′‐bipyridine

A novel cadmium(II) coordination polymer, poly[[[bis­(4,4′‐bipyridine)cadmium(II)]‐μ₃‐4,4′‐dicarboxy­biphenyl‐3,3′‐di­carboxyl­ato] 0.35‐hydrate], {[Cd(C₁₆H₈O₈)(C₁₀H₈N₂)₂]·0.35H₂O}_n, was obtained by reaction of Cd(CH₃COO)₂·3H₂O, 4,4′‐bipyridine (4,4′‐bpy) and biphenyl‐3,3′,4,4′‐tetra­car­boxylic acid (H₄L) under hydro­thermal conditions. Each Cd^II atom lies at the centre of a distorted octa­hedron, coordinated by four O atoms from three H₂L²⁻ ligands and N atoms from two monodentate 4,4′‐bpy ligands. Each H₂L²⁻ ligand coordinates to three Cd^II atoms through two carboxyl­ate groups, one acting as a bridging bidentate ligand and the other in a chelating bidentate fashion. Two Cd atoms, two H₂L²⁻ anions and four 4,4′‐bpy ligands form a ring dimer node, which links into an extended broad zonal one‐dimensional chain along the c axis.