Crystal structures and properties of four coordination polymers constructed from flexible pamoic acid

Four novel coordination polymers constructed from flexible pamoic acid, namely [Co(pam)(4,4′-bipy)]_n·nH₂O (1), [Ni(pam)(4,4′-bipy)(H₂O)₂]_n·2nCH₃CN (2), [Cd(pam)(py)₂]_n·npy (3) and [Mn₂(pam)₂(py)₆(H₂O)₂]_n·2npy (4), (H₂pam = pamoic acid, 4,4′-bipy = 4,4′-bipyridine, py = pyridine), have been synthesized and characterized by elemental analysis, infrared spectra and X-ray crystallography. Complex 1 is a 2-D coordination polymer constructed from chelating bis-bidentate pam and 4,4′-bipyridine bridging ligands. Complex 2 is a 2-D coordination polymer assembled by bis-monodentate pam and 4,4′-bipyridine, where acetonitrile is filled in the rectangle channels. Both 2-D coordination polymers display undulated (4,4) grid layers as sql topology. Complex 3 displays a 1-D polymeric chain using chelating bis-bidentate pam as bridging ligand. Complex 4 exhibits an interesting bis-monodentate pam-Mn(II) 1-D polymeric chain, in which exist two-type six-coordinated manganese centers. Mn(1) is bound to four pyridine ligands, whereas Mn(2) is combined to two pyridine and two H₂O molecules. Their thermal stabilities have been investigated. Cadmium complex 3 displays strong green luminescence with emission maximum at 543 nm.     

Syntheses,structures, and properties of two coordination polymers based on 5-methoxyisophthalate and flexible dipyridines

Hydrothermal reactions of 5-methoxyisophthalic acid (MeO-H₂ip), 1,3-di(4-pyridyl)propane (bpp) with Cd(NO₃)₂·4H₂O and Ni(NO₃)₂·6H₂O produced [Cd₂(MeO-ip)₂(bpp)₂]_n·nH₂O (1) and [Ni(MeO-ip)(bpp)(H2O)]_n·nH₂O (2), respectively. Complex 1 is a 2-D layer consisting of dinuclear Cd(II)-carboxylate units, two carboxylates of MeO-ip adopt μ₂,η²-bridging and chelating modes. MeO-ip bridges three Cd(II) ions to form a 1-D [Cd₂(MeO-ip)₂]_n chain, which is further extended into a 2-D layer by bpp in a trans,trans-conformation. However, two carboxylates of MeO-ip in 2 are monodentate and chelating to link Ni(II) into a 1-D [Ni(MeO-ip)]_n chain with bpp in a trans-gauche conformation connecting [Ni(MeO-ip)]_n chains into a two-fold interpenetrating 3-D network. Coordinated water and carboxylate oxygen from different MeO-ip form strong hydrogen bonds. The frameworks of 1 and 2 are stable below 250 and 300?°C, respectively. Luminescence indicates that 1 shows maximum emission at 375 and 450 nm upon excitation at 320 nm. Magnetic measurement of 2 suggests the presence of ferromagnetic interactions in 2.     

2-D coordination polymers of copper and cobalt with 3,4-pyridinedicarboxylic acid: synthesis,characterization, and crystal structures

Two new complexes involving 3,4-pyridinedicarboxylic acid (3,4-H₂pdc), copper(II) and cobalt(II) complexes, {[Cu(3,4-Hpdc)₂(H₂O)₂]·2dmso}_n (1) and {[Co(3,4-Hpdc)₂(H₂O)₂]·2H₂O·2dmso}_n (2) (dmso = dimethylsulfoxide), have been synthesized by the diffusion method and characterized by elemental analysis, IR spectroscopy, thermal analysis, powder and single-crystal X-ray diffraction analysis, and electron paramagnetic resonance (EPR). In both compounds, the metal coordination sphere is composed of a trans-MO₄N₂ core and adopts a distorted octahedral geometry in accordance with X-ray diffraction and EPR results. 3,4-Hpdc^? ligands bridge the metal centers giving two-dimensional (2-D) coordination polymers with four-connected uninodal nets of (4,4) topology.     

Syntheses,structures, and luminescence of coordination compounds based on N-containing polycarboxylates

Six coordination compounds constructed by two structurally related flexible nitrogen-containing polycarboxylate ligands 2,2′-(2,2′-(ethane-1,2-diylbis(oxy))bis(2,1-phenylene))bis(methylene)bis(azanediyl)dibenzoic acid (H₂L1) and 5,5′-(2,2′-(ethane-1,2-diylbis(oxy))bis(2,1-phenylene))bis(methylene)bis(azanediyl)diisophthalic acid (H₄L2) have been synthesized: [Ni(H₂O)₆]?·?L1?·?(C₂H₅OH)_0.5?·?H₂O (1), [Co(L1)(L3)]?·?CH₃OH (2), [Ni(L1)(L3)]?·?CH₃OH (3), [Zn(L1)(L3)]?·?CH₃OH (4), [Cd(L1)(L3)]?·?CH₃OH (5), and [Zn(L2)_0.5(phen)]?·?C₂H₅OH (6), where L3?=?3,4?:?9,10?:?17,18?:?23,24-tetrabenzo-1,12,15,26-tetraaza-5,8,19,22-tetraoxacyclooctacosan and phen?=?1,10-phenanthroline. The crystal structures have been determined by single-crystal X-ray diffraction. Compound 1 displays a discrete structure, which is further linked by hydrogen bonds to form a 2-D supramolecular layer. Compounds 2–5 display similar structures. These compounds possess 1-D meso-chain structures linked by L1 and metals. The C–H?···?π interactions from neighboring chains extend the chains in different directions, giving a 3-D plywood network. Compound 6 possesses 2-D layers, which are further linked by hydrogen-bonding interactions to generate a 3-D supramolecular architecture.     

Synthesis and crystal structures of two new zigzag versus helical coordination polymers based on diphenic acid

Two new coordination polymers, [Mn(dpa)(2,2′-bipy)] _n (1) and [Ni(dpa)(2,2′-bipy)] _n (2) (H₂dpa = 3,4′-biphenyl-dicarboxylic acid, 2,2′-bipy = bipyridine), have been synthesized and structurally characterized by elemental analysis, IR, and X-ray diffraction. Single-crystal X-ray analyses revealed that 3,4′-diphenic acid acts as a bridging ligand, exhibiting rich coordination modes to link metal ions: μ ₂–η ¹: η ¹, μ ₁–η ¹: η ¹, and μ ₁ –η ¹: η ⁰. Compound 1 demonstrates a 1-D zigzag chain. Compound 2 is a 1-D helical chain. In 1 and 2, there exist intermolecular π–π stacking interactions and non-covalent interactions responsible for the stabilization of the supramolecular structure. In 1, the Mn(II) chains exhibit a weak antiferromagnetic interaction.     

Syntheses,structures and fluorescent properties of three copper cyanide coordination polymers based on N-heterocyclic ligands

Hydrothermal reactions of CuCN, K₃[Fe(CN)₆] with 2,2′-bipyridine, 1,10-phenanthroline or 2,6-bis(1,2,4-triazolyl)pyridine (btp) afford three coordination polymers, [Cu₇(CN)₇(bipy)₂] _n (1), [Cu₂(CN)₂(phen)] _n (2) and [Cu₃(CN)₃(btp)] _n (3). Complex 1 displays 1D polymeric ribbons which are assembled through Cu ··· Cu and π–π stacking interactions into a 3D framework. Complex 2 shows a 1D zigzag chain structure in which phen is a side ligand. In 3, the copper cyanide 2D polymeric networks are connected by tridentate btp to form a 3D metal-organic framework. These coordination polymers exhibit strong fluorescent emissions in the solid state.     

Synthesis,structures and photoluminescence of two Er(III) coordination polymers

Two new erbium compounds, [Er₂(BDC)₃(DMF)₂] (1) and [Er₂(CQC)₃(DMF)₃(H₂O)]?·?DMF?·?H₂O (2), where BDC stands for 1,4-benzenedicarboxylate, CQC for 2-(4-carboxyquinolin-2-yl)quinoline-4-carboxylate, and DMF for N,N-dimethylformamide, have been synthesized through pre-heating and cooling-down crystallization. In 1 the Er(III) is seven-coordinate with oxygen atoms from six BDC and one DMF, forming a three-dimensional open-framework structure. Compound 2 possesses a 2D structure based on dinuclear Er(III) building units. The photoluminescence of 1 has also been investigated.     

Syntheses, crystal structures and properties of two 1-D cadmium(II) coordination polymers based on 1,1′-(1,3-propanediyl)bis-1H-benzimidazole

The combination of framework-builders 1,1′-(1,3-propanediyl)bis-1H-benzimidazole (pbbm), Cd(II) ion and framework-regulator ClO₄⁻ or SO₄²⁻ provides two new coordination polymers [Cd(pbbm)₂(ClO₄)₂]_n(1) and {[Cd(pbbm)SO₄(H₂O)₂]·CH₃OH}_n(2). Both of them display 1-D chain framework, but their detailed structures are clearly different from each other. 1 displays a 1-D ribbon of rings framework, 2 features an interesting infinite 1-D looped chain structure composed of two kinds of rings, the smaller 8-membered ring and the larger 20-membered ring. The antimicrobial activities of the two polymers were tested by the agar diffusion method and the results indicated that they exhibited antimicrobial activities against bacterial strands. The measurement of the non-isothermal kinetics of the thermal decomposition of 2 reveals that there are at least three steps that occur in its decomposition process.     

Yttrium-succinates coordination polymers: Hydrothermal synthesis, crystal structure and thermal decomposition

New polymeric yttrium-succinates, Y₂(C₄H₄O₄)₃(H₂O)₄·6H₂O and Y₂(C₄H₄O₄)₃(H₂O)₂, have been synthesized, and their structures (solved by single crystal XRD) are compared with that of Y₂(C₄H₄O₄)₃(H₂O)₂·H₂O. Three compounds were obtained as single phases, and their thermal behaviour is described.     

Synthesis, crystal structures and thermal properties of new copper(I)halide 2-ethylpyrazine coordination polymers: the influence of solid-state kinetics on product formation

Three new copper(I) coordination polymers were prepared by the reaction of copper(I) chloride with 2-ethylpyrazine in water at room temperature or under solvothermal conditions. In poly[CuCl(μ₂-2-ethylpyrazine-N,N′)] (I), “zig-zag”-like CuCl chains are present, which are connected by the 2-ethylpyrazine ligand to a three-dimensional network. In comparison in catena[Cu₃Cl₃(μ₂-2-ethylpyrazine-N,N′)₂] (II) six-membered Cu₃Cl₃ rings occur, which are connected to chains by the organic ligands. In poly[Cu₂Cl₂(μ₂-2-ethylpyrazine-N,N′)] (III), CuCl double chains are found, which are linked by the ligands to form sheets. The thermal behaviour of the different compounds was investigated using simultaneous thermogravimetry, differential thermoanalysis and mass spectroscopy as well as temperature-dependent X-ray powder diffraction. Two mass steps are found upon heating compound I in a thermobalance with 1°C/min, where the first corresponds to the transformation into compound III, and the second to the loss of the remaining ligands under formation of CuCl. If the heating rate is increased to 16°C/min, compound II is formed as an intermediate in a consecutive reaction. Therefore, the product formation depends on the actual heating rate, which shows that the solid-state kinetics plays an important role in such thermal reactions.     

Syntheses and structures of three new coordination polymers with the flexible 1,2-bis(1,2,4-triazol-1-yl)ethane ligand

Three new coordination polymers {[Ni(bte)₂(NCO)₂](H₂O)} _n (1), {[Ni(bte)₂(N₃)₂](H₂O)} _n (2) and {[Ag(bte)₂](NO₃)} _n (3) (bte?=?1,2-bis(1,2,4-triazol-1-yl)ethane) were synthesized and characterized by X-ray crystallography, IR and thermogravimetric analysis. The coordination geometry of the Ni(II) atom is distorted octahedral, coordinated equatorially by four nitrogen atoms from four triazole rings of four symmetry-related bte ligands, and axially by two nitrogen atoms from two isocyanate anions in 1 and azide anions in 2, respectively. The structures of 1 and 2 are both polymeric, with 18-membered spiro-fused rings and each 18-membered ring involving two inversion-related bte molecules. The coordination geometry of the Ag(I) atom in 3 is distorted tetrahedral, formed by four nitrogen atoms from four triazole rings of four symmetry-related bte ligands. Each bte ligand links two Ag(I) atoms and forms a two-dimensional undulated (4,4) network in 3.     

Syntheses,crystal structures,and magnetic properties of 1-D coordination polymers

Three coordination polymers of Robson-type macrocycles, {[Cu₄L¹(4,4′-bipy)₂]·4ClO₄·H₂O}_∞ (1), {[Cu₄L²(4,4′-bipy)₄]·2CH₃CN·4ClO₄·2H₂O}_∞ (2), and {[Zn₂L²(4,4′-bipy)₂]·(ClO₄)₂}_∞ (3) (where H₂L¹ and H₂L² are the [2?+?2] condensation products of 1,3-diaminopropane with 2,6-diformyl-4-methylphenol and 2,6-diformyl-4-fluorophenol, respectively), have been synthesized and characterized. Magnetic susceptibility was measured for 1 and 2 from 2 to 300?K. The optimized magnetic data were J?=?–368.5?cm^?1, J′?=?40.5?cm^?1 with R?=?1.69?×?10^?6 for 1 and J?=?–291.22?cm^?1, J′?=?83.74?cm^?1, ρ = 0.00168 with R?=?1.8?×?10^?11 for 2, respectively. The data reveal strong antiferromagnetic interactions between two Cu(II) ions in the macrocyclic unit and ferromagnetic interaction between the Cu(II) ions in two adjacent macrocyclic units for 1 and 2.     

Synthesis, structures, luminescent and magnetic properties of four coordination polymers with the flexible 1,3-phenylenediacetate ligands

Four coordination polymers, [Zn(pda)(bpy)(H₂O)]_n·nH₂O (1), [Cd(pda)(prz)(H₂O)]_n (2), [Co₃(μ₃-OH)₂(pda)₂(pyz)]_n·2nH₂O (3) and [Pr₂(pda)₃(H₂O)₂]_n (4) (H₂pda=1,3-phenylendiacetic acid, bpy=4,4′-bipyridine, prz=piperazine and pyz=pyrazine) have been hydrothermally synthesized and characterized. Complex 1 is a 1D wheel-like chain structure, which is further extended into a 3D metal-organic supramolecular framework by H-bonds and π-π stacking interactions. Complex 2 is a 1D ladder-like chain structure, which is also further extended into a 3D metal-organic supramolecular framework by H-bonds. Complex 3 possess a 2D sheet structure with infrequent two pairs of double-helix chains. Complex 4 features a 3D structure. Both 1 and 2 display strong blue fluorescent emission at room temperature. Magnetic susceptibility measurements of complexes 3 and 4 exhibit antiferromagnetic interactions between the nearest metal ions, with C=9.99 and 3.43 cm³ mol⁻¹ K, and θ=−23.9 and −46.3 K, respectively.     

Synthesis,crystal structures,and characterization of two Co(II) coordination polymers with 3-pyrid-3-ylbenzoic acid

Two pyridinecarboxylato-bridged coordination polymers {[Co(pbc)₂(H₂O)] · H₂O} _n (1) and [Co(pbc)₂] _n (2) (Hpbc = 3-pyrid-3-ylbenzoic acid) have been synthesized by the hydrothermal method and characterized by X-ray single crystal diffraction. In 1, pbc^? ligands link two Co(II) centers as μ₂-N,O and μ₂-N,O,O. Co(II) is six coordinate, octahedral. In 2, Co(II) is coordinated by four oxygens and two nitrogens. The ligands are μ₂-N,O,O and μ₃-N,O,O. Through different pbc^? ligands, 2 generates a 3-D network composed of six-connected nodes. Compound 2 exhibits good photoluminescence, whereas 1 is nonemissive at room temperature.     

Three novel Cd(II) coordination polymers: Synthesis,crystal structures,fluorescence and thermal properties

Three novel Cd(II) coordination polymers, {[Cd(C₄BIm)(N₃)(OAc)]·C₂H₅OH}_n (1), [Cd(C₄BIm)(H₂O)₃(SO₄)]_n (2) (C₄BIm = 1,4-bis(benzimidazolyl)butane) and [Cd(bbbm)_1.5(NO₃)₂]_n (3) (bbbm = 1,1′-(1,4-butanediy)bis-1H-benzimidazole) have been prepared and characterized spectroscopically and crystallographically. In polymer 1, C₄BIm–Cd chains and N₃–Cd chains criss-cross to a layer structure. Polymer 2 possesses a concave–convex chain structure. Polymer 3 exhibits a two-dimensional (2-D) rhomboid grid network, the dimensions of the grid is 25.807 × 13.771 Å, and the diagonal-to-diagonal distances are 28.608 × 21.145 Å. The fluorescence properties and the thermal stabilities of the three polymers were investigated.     

Syntheses and structures of three new coordination polymers with the flexible 1,4- bis (imidazol-1-yl)butane ligand

Three new coordination polymers [Co(bimb)₂(NCS)₂] _n (1), {[Co(bimb)₂(dca)₂]?·?CH₃CN} _n (2) and [Cu(bimb)₂(NO₃)₂] _n (3) (bimb?=?1,4-bis(imidazol-1-yl)butane, dca?=?dicyanamide) were synthesized and characterized. In 1, each Co(II) links two Co(II)'s by double bimb ligands and extends to form a one-dimensional chain containing the Co₂(bimb)₂ 22-membered metallocycle. 2 and 3 are two-dimensional (4, 4) networks linked by bimb bridges. The conformations of the bimb ligands in 1, 2 and 3 are analyzed.     

Syntheses, structures and properties of five copper coordination polymers constructed by the triazole ligand

Reactions of different metal salts with 4-amino-3,5-bis(3-pyridyl)-1,2,4-triazole (3-abpt) gave rise to five new complexes, namely [Cu₄(CN)₄(3-abpt)₂]_n (1), [CuBr(3-abpt)]_n (2), [CuI(3-abpt)]_n (3), [Cu₃I₃(3-abpt)]_n (4) and [Cu(3-abpt)(SO₄)(H₂O)]_n (5). Compounds 1, 3, 4 and 5 are all 2D structures. Compound 1 is a double-layered polymer with an uncommon 3-nodal 3-connected (10³)(10².4)₄ network, 3 shows a 2D square layered structure, 4 is also a double-layered polymer with 2-nodal 4-connected (3.4.5.6².7)₂(3.4².5².7) network and 5 is a 2D structure which is ultimately stacked with an ABAB repeat pattern. Compound 2 is a 1D coordination polymer which exhibits a ladder-like network. The photoluminescence of 1-2 has also been investigated. The long emission lifetimes of 1-2 could be assigned to metal-to-ligand charge transfer triple excited states [MLCT].     

Design,synthesis and structure of uranyl coordination polymers from 2-D layer to 3-D network structure

Solvothermal reaction of uranyl acetate and succinic acid in DMF resulted in formation of three uranyl coordination polymers, [(UO₂)₄(μ₂-OH)₇(OH)₆]·2(H₂O)·(H₃O)·4NH₂(CH₃)₂ (1), [(UO₂)(μ₂-OH)(OH)₃]·2NH₂(CH₃)₂] (2), and [(DMF)₂(UO₂)(μ₂-OH)₄(UO₂))] (3). The products were characterized by elemental analysis, IR spectroscopy, X-ray single crystal, and powder diffraction. Structural analysis shows that 1 is a layer, 2 and 3 are 3-D network structures.     

Syntheses and characterizations of three coordination polymers based on dipyridylbenzoates and 1,4-bezenedicarboxylate

Three coordination polymers, namely [Ni(3,4-pmb)(bdc)_0.5] (1), [Co(3,5-pmb)(bdc)_0.5] (2) and [Cd(3,5-pmb)(bdc)_0.5] (3) (3,4-pmb = 3,4-bis[4-pyridylmethyleneoxyl]benzoate, 3,5-pmb = 3,5-bis[4-pyridylmethyleneoxyl]benzoate and bdc = 1,4-benzenedicarboxylate), have been synthesized by the hydrothermal method and structurally characterized. The X-ray structural analysis reveals that the three complexes possess different structural motifs. Complex 1 has a three-dimensional (3D) threefold interpenetrated diamondiod architecture and crystallizes in the monoclinic C2/c space group, in which each Ni(II) atom is connected to four other Ni(II) centers, resulting in the formation of a (4,4) diamondoid network. Complex 2 is a (3D) fourfold interpenetrated polyrotaxane and crystallizes in the monoclinic P2(1)/c space group. It is constructed by four equivalent independent 3D units and entangled by each other give a 3D fourfold structure. Complex 3 is a 2D network in which two Cd(II) centers are bridged equivalently by four carboxylate groups of different pmb and bdc ligands, forming a paddle wheel secondary building unit (SBU) (CdO₄N), and the five coordinating atoms in the CdO₄N unit occupy the vertices of square-pyramidal structure. Moreover, complex 3 exhibits strong photoluminescence at room temperature.     

Assembly,crystal structures,and luminescent properties of three new thiocyanate-bridging mercury(II) coordination polymers

Two ligands, 2-{5,5-dimethyl-3-[2-(pyridin-3-yl)-ethenyl]cyclohex-2-enylidene}propanedinitrile (L1) and 2-{5,5-dimethyl-3-[2-(pyridin-2-yl)-ethenyl]cyclohex-2-enylidene}propanedinitrile (L2), were synthesized. By reaction of mercury thiocyanate with L1 and L2, respectively, coordination polymers [Hg(L1)(μ_1,3-SCN)₂]_n (1), [Hg(L1)₂(μ_1,3-SCN)₂]_n (2), and [Hg(L2)(μ_1,3-SCN)(SCN)]_n (3) with different structures and topologies were obtained. In 1, the thiocyanate shows μ_1,3-SCN bridging coordination, and adjacent Hg(II) ions are bridged by two μ_1,3-SCN ions to form an infinite chain with the remaining position of five-coordinate Hg(II) occupied by L1. In 2, the thiocyanate has the same coordination as 1. However, Hg(II) has octahedral coordination with two L1 involved in coordination. An unusual feature of 3 is the presence of two types of thiocyanates, one has a S-terminal ligand and the other has a μ_1,3-SCN bridge. The mercury(II) in 3 is four-coordinated by L2 and three thiocyanates. Luminescent properties and thermal stabilities of 1–3 were studied.