Assembly of one 2D layer and two 3D pillared-layer structures derived from metal ions and 5-(pyridin-4-yl)isophthalic acid with or without pillars

Three new coordination polymers, [Mn(L)(H₂O)₂]₂·5H₂O (1), [Cu(L)(4,4′-bipy)]₂·H₂O (2) and [Pb(L)(4,4′-bipy)_0.5] (3) (H₂L = 5-(pyridin-4-yl)isophthalic acid; 4,4′-bipy = 4,4′-bipyridine) have been synthesized and characterized by IR, thermogravimetric analysis, X-ray powder diffraction and X-ray single crystal diffraction. Complex 1 shows a 2D layer structure which stacks with the other ones to form 1D channels to hold 1D water chains. Complex 2 displays a 3D + 3D → 3D polycatenation network. 3 shows a unique 2D + 2D → 3D polycatenation net in which each Pb center has a hemidirected coordination geometry due to the existence of “inert pair effect”. The thermal and luminescent properties of 1–3 were also examined.     

Construction of two mixed-ligand coordination polymers presenting unusual polyrotaxane-like entanglements

Two novel polyrotaxane-like coordination polymers, [Ni₄(L)₄(H₂O)₃(bpp)₄]·3H₂O (1) and [Cd₄(L)₄(bpp)₃]·3H₂O (2) (H₂L = Me₂Si(p-C₆H₄COOH)₂, bpp = 1,3-bis(4-pyridyl)propane), have been synthesized and structurally characterized. Compound 1 features a 2D → 3D polyrotaxane array by the interlock of bilayer networks. Compound 2 exhibits an unusual 3D polyrotaxane-like self-threading framework. In addition, compound 2 shows an emission at 485 nm when it was excitated at 400 nm.     

Novel silver(I) compounds assembled from hybrid ligands based on linear or T-shaped coordination environment

Two novel 1D compounds {[Ag₃(Hbptc)(bpa)₂]·H₂O}_n (1) and [Ag₂(H₂bptc)(bpp)₂]_n (2) (H₄bptc = 3,3′,4,4′-benzophenonetetracarboxylic acid, bpa = 1,2-bis(4-pyridyl)ethane and bpp = 1,3-bis(4-pyridyl)propane) were synthesized and structurally characterized. The crystal structures of compounds exhibit two kinds of ladder-like chains based on linear or T-shaped coordination environment of Ag(I). Fluorescence spectra of compounds 1 and 2 indicate the unusual intensity of fluorescent emission upon photoexcitation which may be attributed to ligand-to-metal charge transfer and Ag–Ag interactions.     

3D PbII-coordination framework based on rod-shaped Pb–O–Pb SBUs defining a new (4,5)-connected net topology

A novel 3D coordination framework [Pb₂(hfipbb)₂(bpp)]_n (1) [H₂hfipbb = 4,4′-(hexa-fluoroisopropylidene)bis(benzoic acid), bpp = 1,3-bis(4-pyridyl)propane] based on inorganic rod-shaped infinite Pb–O–Pb chain is presented, which possesses a new (4,5)-connected network topology and shows high thermal stability and strong photoluminescence at room temperature.     

Two new Keggin-type polyoxometalate-based entangled coordination networks constructed from metal-organic chains with dangling arms

Two new polyoxometalate(POM)-based entangled coordination networks with chemical formula of [Mn₂(H₂O)₂(BBPTZ)₅][SiW₁₂O₄₀] (1) and [Ni₂(H₂O)₂(BBPTZ)₅][SiMo₁₂O₄₀]·6H₂O (2) (BBPTZ = 4.4′-bis(1,2,4-triazol-1-ylmethyl)biphenyl), were prepared in a hydrothermal reaction system. Compounds 1–2 were characterized by elemental analyses, IR spectroscopy, thermogravimetric analysis, powder X-ray diffraction and single-crystal X-ray diffraction. In compound 1, dangling arms thread in quadrangular window of the adjacent 2-D layers, thus resulting in a rare 2-D → 3-D polythreading motif. Compound 2 exhibits a rare 2-D → 3-D zipper-closing motif. Using the degradation of methylene blue (MB) as the model, the photocatalytic activities of compounds 1–2 were investigated. Both compounds show efficient catalytic activity for the degradation of MB with the order of 2 > 1. It is found that the POM species of compounds 1–2 play the main role in the photocatalytic degradation process.     

A three-dimensional zincic molybdenum (V) phosphate with helical channel: Synthesis,structure, and electrochemical properties

A new reduced zincic molybdophosphate, (H₂bpp)₃[Zn₃Mo₁₂^VO₂₄(OH)₆(H₂O)₂(HPO₄)₆(PO₄)₂]·2H₂O 1 (bpp = 1,3-bis(4-pyridyl)propane) has been hydrothermally synthesized and characterized by elemental analysis, IR, TG, and single-crystal X-ray diffraction. Compound 1 crystallizes in the tetragonal space group I 41/a c d with a = 31.8033(4) Å, b = 31.8033(4) Å, c = 34.5593(8) Å, V = 34955.0(10) ų, and Z = 16 and exhibits a 4,6-connected 3-D framework with (3².8⁴)(3⁴.4².8³.9⁵.10) topology. The basic building blocks of [Zn(2)(Mo₆P₄)₂] are linked through [Zn(3)O₆] octahedra and [Zn(1)O₄] tetrahedra to construct 1-D chains along four different directions. Such 1-D chains are further connected by [Zn(1)O₄]²⁺ linkers to form a 3-D intricate framework with helical channels occupied by protonated bpp and water molecules. Additionally, the electrochemical property of the 1-CPE has been studied in detail.     

An unusual 3D three-fold parallel interpenetrating network self-assembled from the grid-containing 2D layer motifs

The new complex {[Cu(dde)(bpe)] · H₂O}_n (1) (dde = 4,4′-dicarboxydiphenyl ether, bpe = 1,2-bis(4-pyridyl)ethene) has been synthesized and characterized. It exhibits a novel (2D → 3D) three-fold parallel interpenetrating architecture that is obtained for the first time from the self-assembly of grid-containing 2D (4, 4) layer motifs. The fluorescent property of 1 is discussed.     

A novel 3D twofold interpenetrating microporous metal-organic framework containing 1D water tapes with cyclic pentamer units

The self-assembly of Cu²⁺ ions with malate and 1,3-bis(4-pyridyl)propane (bpp) affords a 3D coordination polymer {[Cu(Hmal)(bpp) · 6H₂O]}_n (1) (malic acid = H₃mal). The metal ions were interconnected by α- and β-carboxylate of malate produce infinite [Cu(C₄H₄O₅)]_n layers, which were further pillared by bridging ligand bpp molecules to form a 3D interpenetrating network. Of further interest, lattice water molecules form 1D infinite water tapes in 1D open cavities.     

A new 3D Cd(II) metal–organic framework with discrete (H2O)6 clusters based on flexible cyclohexane-1,2,4,5-tetracarboxylic acid ligand

A 3D metal–organic framework (MOF), {[Cd₂(CTA)(bpp)₂(H₂O)₂] (H₂O)₃}_n (1) (H₄CTA = cyclohexane-1,2,4,5-tetracarboxylic acid, bpp = 1,3-bis(4-pyridyl)propane), has been synthesized and structurally characterized by elemental analysis, IR and powder X-ray diffraction. Single-crystal X-ray measurement reveals that the complex presents three-dimensional frameworks with 1D channels which are filled by unique (H₂O)₆ clusters. Noteworthily, the H₄CTA ligands keep exclusive conformation, where the carboxyl groups adopt different coordination modes, and the bpp ligands perform two different conformations. Thermogravimetric analysis demonstrates that 1 features favorable thermal stability. Photoluminescence property of 1 is investigated in the solid state at room temperature as well.     

Two highly connected frameworks and one polythreading architecture based on multidentate N-donor ligands: Syntheses,structures, characterizations and photoluminescent properties

Three coordination polymers based on multidentate N-donor ligands and polycarboxylate anions, namely, [Co₃(4,4′-tmbpt)₄(btc)₂]·9.5H₂O (1), [Ag₄(4,4′-tmbpt)(btec)(H₂O)₂]·H₂O (2) and [Zn(4,4′-tmbpt)(btec)_0.5(H₂O)]·0.5H₂O (3) (4,4′-tmbpt = 1-((1H-1,2,4-triazol-1-yl)methyl)-3,5-bis(4-pyridyl)-1,2,4-triazole, H₃btc = 1,3,5-benzenetricarboxylic acid, and H₄btec = 1,2,4,5-benzenetetracarboxylic acid) have been prepared under hydrothermal condition. Compound 1 displays a 3D (3,6,8)-connected framework with (4·6²)(4⁴·6¹⁰·8)(4¹⁴·6¹²·8²) topology. Compound 2 is a 3D (4,5,8)-connected framework with (4³·6²·8)(4³·6⁵·8²)(4⁸·6²)(4¹⁰·6¹⁰·8⁸) topology. Compound 3 exhibits a 2D → 3D polythreading architecture. The photoluminescent spectra indicate that at room temperature, compounds 2 and 3 emit green and blue luminescence, respectively.     

A novel three-dimensional cadmium(II) coordination polymer constructed from dinuclear molecular building block,syntheses, structure and photoluminescence property

A novel cadmium(II) coordination polymer, [Cd₂(pzdc)₂(4,4′-bpy)₂]·4H₂O (1) (H₂pzdc = pyrazine-2,3-dicarboxylic acid; 4,4′-bpy = 4,4′-bipyridine), has been synthesized by hydrothermal reaction of Cd(OAC)₂, H₂pzdc and 4,4′-bpy. Single-crystal X-ray diffraction analysis reveals that 1 constructed from dinuclear building blocks has a three-dimensional (3-D) structure with rob topology. Fluorescent measurement of 1 exhibits strong blue-green emission in the solid state at room temperature, and its framework possess remarkable thermal stability.     

Three 3D Cu(II) coordination polymers constructed from 1,2,4,5-benzenetetracarboxylate acid and three positional isomeric ligands

Based on 1,2,4,5-benzenetetracarboxylate acid (H₄btc), and mixed with three isomeric dipyridyl ligands, three novel 3D Cu(II) coordination polymers [Cu₂(btc)(4,4′-bpt)]·2H₂O (1) [4,4′-bpt = 1H-3,5-bis(4-pyridyl)-1,2,4-triazole], [Cu(btc)_0.5(3,4′-bpt)]·0.5H₂O (2) [3,4′-bpt = 1H-3-(3-pyridyl)-5-(4-pyridyl)-1,2,4- triazole] and [Cu(btc)_0.5(3,3′-bpt)]·2H₂O (3) [3,3′-bpt = 1H-3,5-bis(3-pyridyl)-1,2,4-triazole] have been synthesized and characterized, respectively. 1 is a 3D pillared double-layer complex containing a novel bilayer unit; 2 is a 3D pillared-layer architecture with (4,4)-sql layer; 3 exhibits a 3D structure containing 3D [Cu(btc)]_∞ motif and 1D [Cu(bpt)]_∞ chain. The topological analysis shows that 1 can be simplified to a (4,6)-connected network with the Schläfli symbol of (4²·6⁴)₂(4⁸·6⁷), 2 a (4,6)-connected network with the symbol of (4⁴·6²)(4⁴·6¹⁰·8), and 3 a four-connected topology with the symbol of (3²·10³·11)₂(3²·10⁴).     

Synthesis and characterization of nickel phosphonopropionate hybrid materials

Hydrothermal reaction of nickel acetate with 3-phosphonopropionic acid and 4,4′-bipyridine resulted in two novel phosphonate compounds Ni(HO₃PC₂H₄COO)(4,4′-bpy)(H₂O) · 0.5(4,4′-bpy) (bpy = bipyridine) (I) and Ni(O₃PC₂H₄COOH)(4,4′-bpy)(H₂O)₃ · H₂O (II). Single-crystal X-ray studies reveal that self-assemblies between the ligands and metal ion result in layer (I) and chain (II) structures. Magnetic measurement of I indicate there are ferromagnetic couplings between adjacent Ni²⁺ ions (C = 1.29 cm³ mol⁻¹ K and θ = 2.25 K).     

A new 3D coordination framework with helical chains in mixed ligands system: Preparation,crystal structure and magnetic property

A new 3D coordination polymer [Ni₂(L)₂(bpp)₂(μ₂-H₂O)] (1) (H₂L = 2,4-dibenzoylisophthalic acid and bpp = 1,3-bis(4-pyridyl)propane) has been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectra, and thermogravimetric analysis. Further, it was determined by single crystal X-ray diffraction analysis. Compound 1 is a 3D network with (3⁶·4⁸·5⁷) topology, which comprises of two kinds of helical chains. Additionally, compound 1 shows ferromagnetic interactions among metal ions.     

1D lead(II) coordination chains with carboxylate containing ligands. A rare example of polyrotaxane 1D → 1D interpenetrated coordination polymer

The structural determination of two interesting lead(II) coordination polymers, namely [Pb(ind)₂(H₂O)]_n (1) and [Pb₂(dbsf)₂(bipy)]_n (2) (Hind = indane-2-carboxylic acid, H₂dbsf = 4,4′-sulfonyldibenzoic acid, and bipy 4,4′-bipyridine), reveals in the second an unexpected polyrotaxane 1D → 1D interpenetrated coordination polymer thanks to the hemidirected coordination geometry of the metal and the rings formed by the dicarboxybiphenyl sulfone ligands along the 1D chain.     

Two 3D coordination polymers constructed from flexible desymmetric carboxylate and neutral nitrogen ligands

Two coordination polymers based on a flexible desymmetric ligand precursor H₂L have been synthesized, that is, [Ni(L)(dpe)_3/2] H₂O (1), [Ni₂(H₂O)(L)₂(bpp)₂] H₂O (2), [H₂L = 4,4′-(phenylazanediyl)dibenzoic acid, dpe = 1,2-di(pyridin-4-yl)ethane, bpp = 1,3-di(pyridin-4-yl)propane]. These complexes were characterized by elemental analysis, IR spectroscopy, X-ray single-crystal and power diffraction. In addition, the second nonlinear optical properties of 2 were measured.     

Template-assisted assembly of porous lanthanide coordination polymers with 2-aminoterephthalic acid

Porous lanthanide coordination polymers, {[Ln₂(atpt)₃(H₂O)₂] · 0.5(4,4′-bpy)(H₂O)}_n [Ln = Eu(1), Gd(2), Yb(3), H₂atpt = 2-aminoterephthalic acid, 4,4′-bpy = 4,4′-bipyridine] were obtained by hydro-solvothermal reaction, in which 4,4′-bpy acts as template. For the first time the nitrogen atom of an atpt ligand coordinates to metal ions in 1–3. The photophysical properties and thermal stability of 1 were investigated.     

Two 2-D 4-connected lanthanide coordination framework based on benzimidazole-5,6-dicarboxylate and acetate mixed ligands

Two 2-D polymers, [Ln(bidc)(Ac)·H₂O]_n (Ln = Tb(1), Dy(2) H₂bidc = benzimidazole-5,6-dicarboxylic acid, HAc = acetic acid), have been successfully synthesized under hydrothermal conditions at 150 °C and characterized by elemental analysis, infrared spectra and single-crystal X-ray diffraction. Single crystal X-ray diffraction analyses reveal that the two compounds are isomorphous and exhibit one new (4,4)-connected 2-nodal (4⁴·6²)(4⁴·6²) layer-like net, stabilized by the interchain hydrogen bonding N–H?O, O–H?O and π?π stacking interactions between two benzimidazole rings. 2-D layers are further connected by the interlayer O–H?O hydrogen-bonding interactions to form a 3-D supermoleculaer network. Moreover, the luminescent property of compound 1 and thermogravimetric analyses of the two complexes 1–2 are discussed in detail.     

A new bitrack sinusoid-like chain templated by Wells–Dawson type polyoxometalate

A new Wells–Dawson type polyoxometalate (POM)-templated compound, [Cu₄(μ₂-O)₂(4,4′-bpo)₄(INA)₂(H₂O)₄][(P₂W₁₈O₆₂)]·H₂O (1) (4,4′-bpo = 2,5-bis(4-pyridyl)-1,3,4-oxadiazole; INA = pyridine-4-carboxylic acid), has been hydrothermally synthesized. Compound 1 contains a novel bitrack sinusoid-like chain constructed from alternating dicopper units and non-linear rigid 4,4′-bpo linkers. Induced by POM templates, the adjacent chains formed elliptical spaces to accommodate the Wells–Dawson type anions.     

A new helical coordination polymer constructed on flexible dicarboxylate ligand and CdII center: Structure and luminescence

A novel cadmium coordination polymer [Cd₂L₂(bpp)₂]_n (1) (H₂L = 1,3-adamantanediacetic acid and bpp = 1,3-di-4-pyridylpropane) was prepared under hydrothermal condition. The three-dimensional (3D) structure is built from the interlinking lamellars. The Cd^II ions are six- and seven-coordinated and linked by L^2? ligands, which results in the right- and left-handed helical chains. The layers are stacked with each other via bpp to generate a 3D architecture. At room temperature, the complex 1 shows the strong fluorescent emission bands in the solid state.