Hydrothermal synthesis, crystal structure and properties of 2-D and 3-D lanthanide sulfates

Two new lanthanum sulfates DySO₄(OH) 1 and Eu₂(SO₄)₃(H₂O)₈2 have been hydrothermally synthesized. The colorless crystals were characterized by IR, TGA, ICP and XRD. The structure was determined by single-crystal X-ray diffraction. 1 crystallizes with monoclinic symmetry, space group P2(1)/n [a=7.995(4) Å, b=10.945(5) Å, c=8.164(4) Å, α=90°, β=93.619(6)°, γ=90°, V=713.0(5) Å³, Z=8]. It displays a three-dimensional framework, based on the novel Dy-O chains connected by the sulfate groups through helical chains. 2 crystallizes with monoclinic symmetry, space group C2/c, [a=13.5605(17) Å, b=6.7676(8) Å, c=18.318(2) Å, α=90°, β=102.265(2)°, γ=90°, V=1642.7 (4) Å³, Z=4]. Its layered framework is attained by the europium atoms connected by the sulfate groups arranged in a helical manner.     

Hydrothermal synthesis,characterization and photoluminescence property of a novel indium phosphate with 3D supramolecular structure

A one-dimensional chained indium phosphate In(H₂PO₄)(HPO₄)(C₁₀N₂H₈) (1) was synthesized under hydrothermal condition using 2,2′-bipyridine as a ligand and characterized by IR spectroscopy, ICP and elemental analyses, powder and single crystal X-ray diffraction analyses. Compound 1 crystallizes in the triclinic system, space group P-1. The connection of In-centered octahedra (InO₄N₂) and P-centered tetrahedra ({PO₃(OH)} and {PO₂(OH)₂}) constructs a new type of 1D chained structure with In/P ratio of 1/3. Interestingly, H₂PO₄ tetrahedron and 2,2′-bipyridine ligands "hanging" in the chain by bridging oxygen atoms and nitrogen atoms bond to the central In atoms. It is noted that the adjacent chains are stably packed together and the final structure exhibits interesting three-dimensional (3D) supramolecular array via π–π interactions of the 2,2′-bipyridine groups and hydrogen-bond interactions. Additionally, compound 1 shows strong photoluminescence property in the solid state at room temperature.     

Two new polyoxometalate-based organic-inorganic hybrids: synthesis,crystal structure and characterization

Two new organic-inorganic hybrids, (4,4′-bipy)[Cu^I(2,2′-bipy)₂]₂[W₆O₁₉] (2,2′-bipy = 2,2′-bipyrine, 4,4′-bipy = 4,4′-bipyrine) (1) and (C₆H₅NO₂)₄{Mn^III(H₂O)}[As^IIIW₉O₃₃]₂{W(OH)}- {W(H₂O)}?～18H₂O (2), have been synthesized and characterized by elemental analysis, IR, TG, UV–Vis, XRPD, XPS, electrochemical analysis and single-crystal X-ray diffraction. Single crystal X-ray diffraction analysis shows that 1 is a new Lindqvist-type polyoxoanion bisupported by copper(I) coordination cations and 2,2′-bipy ligands and exhibits a three-dimensional (3-D) supermolecular framework by aromatic π–π stacking interactions. Compound 2 is constructed from a manganese(III)-substituted sandwich-type polyoxoanion based on [α-AsW₉O₃₃]^9? units and dissociative, protonated pyridine-4-carboxylic acid molecules, which act as the charge compensation cations. The cyclic voltammogram of 2 shows an irreversible redox process for Mn³⁺ ions.     

pH-Directed assembly of four polyoxometalate-based supramolecular hybrids by using tritopic bridging ligand 1, 3, 5-tris-(1-imidazolyl)-benzene: Structures and electrocatalytic properties

Four new inorganic-organic supramolecular compounds, namely, (H₂tib)₂[GeW₁₂O₄₀] (1), [Mn(Htib)₄][HGeW₁₂O₄₀]₂·4H₂O (2), [Mn(tib)]₂(H₂O)₆[GeW₁₂O₄₀]·4H₂O (3) and [Mn(tib)]₂(H₂O)₆[GeW₁₂O₄₀]·2H₂O (4) (tib = 1, 3, 5-tris-(1-imidazolyl)-benzene), have been synthesized through the hydrothermal reaction of [GeW₁₂O₄₀]^4- anions, Mn^II cations and tib ligands under different pH conditions. Compounds 1 and 2 were prepared at lower pH (pH ≈ 2.0 for 1 and 3.2 for 2). Compound 1 exhibits a simple monomer structure. In 2, the Mn cation is coordinated with four tib ligands and two [GeW₁₂ O₄₀]^4- anions to form a dimer, in which each of [GeW₁₂ O₄₀]^4- anion connects with one Mn cation. Compounds 3 and 4 were prepared at higher pH (pH ≈ 4.2 for 3 and 4.9 for 4), and compounds 3 and 4 display a one-dimensional (1D) chain and a (4, 4)-connected 2D wave-like layer, respectively, and in compound 3, each of GeW₁₂ cluster connects two Mn atoms, however, compound 4: each of GeW₁₂ cluster connects four Mn atoms. The isolation of these four compounds is very informative for systematically understanding the effect of the pH on assembly of polyoxometalate-based hybrids. Also, the electrocatalytic properties of 1–4-CPEs towards nitrite have also been investigated.     

One new lanthanide complex with mixed sulfate and oxalate ligands: hydrothermal synthesis,crystal structure,and magnetic properties

A new lanthanide complex K[Gd(ox)(SO₄)(H₂O)] (1) with sulfate and oxalate ligands has been synthesized under hydrothermal conditions. The compound crystallizes in the monoclinic space group P₂₁/c with a = 6.5849(1) Å, b = 8.5660(1) Å, c = 14.7660(2) Å, β = 112.470(1)°, C₂H₂GdKO₉S, M = 398.46, Z = 4, V = 769.66(2) ų, F(000) = 740, R ₁ = 0.0199 and ωR = 0.0514. The solid-state DC magnetic susceptibility measurements of 1 revealed antiferromagnetic behavior with an S = 7/2 ground spin state.     

Hydrothermal synthesis,crystal structure,and electrochemical property of a new 3-D coordination polymer based on benzene-1,2,4,5-tetracarboxylate bridging ligand: [Cu2(btec)(en)2] n

A new 3-D copper(II) complex, formulated as [Cu₂(btec)(en)₂] _n (1) [H₄btec = benzene-1,2,4,5-tetracarboxylate, and en = ethylenediamine], was hydrothermally synthesized and structurally characterized by elemental analysis, IR spectroscopy, thermal gravimetric analysis, and single crystal X-ray diffraction. The structural analysis of 1 reveals that copper(II) connect by μ₆-bridging btec to form a 3-D coordination polymer, in which four carboxylates of btec show monodentate and bidentate coordination. Complex 1 was used as solid bulkmodifier to fabricate renewable carbon paste electrode (1-CPE) by direct mixing method. The cyclic voltammogram of 1-CPE displayed one-electron quasi-reversible redox waves in potential range 300 to ?300 mV due to Cu(II)/Cu(I). Moreover, 1-CPE showed electrocatalytic activity toward the reduction of nitrite.     

Hydrothermal synthesis and characteristics of 3-D hydrated bismuth oxalate coordination polymers with open-channel structure

Two new 3-D porous bismuth coordination polymers, (C₅NH₆)₂[Bi₂(H₂O)₂(C₂O₄)₄]·2H₂O 1 and (NH₄)[Bi(C₂O₄)₂]·3H₂O 2, have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic symmetry, P2₁/c space group with a=10.378(2) Å, b=17.285(3) Å, c=16.563(5) Å, α=90°, β=119.66(2)°, γ=90°, V=2581.8(10) Å³, Z=4, R₁=0.0355 and wR₂=0.0658 for unique 4713 reflections I >2σ(I). Compound 2 crystallizes in the tetragonal symmetry, I4₁/amd space group with a=11.7026(17) Å, b=11.7026(17) Å, c=9.2233(18) Å, α=90°, β=90°, γ=90°, V=1263.1(4) Å³, Z=32, R₁=0.0208 and wR₂=0.0518 for unique 359 reflections I> 2σ(I). Compounds 1 and 2 are 3-D open-framework structures with a 6⁶ uniform net, which consist of honeycomb-like layers connected to each other by oxalate units. While different guest molecules fill in their cavities of honeycomb-like layers, study of ultrasonic treatment on 2 indicates the replacement of NH₄⁺ by K⁺ on potassium ion exchange. Thermogravimetric analysis indicates that the open-channel frameworks are thermally stable up to 200 °C, and other characterizations are also described by elemental analysis, IR and ultraviolet-visible diffuse reflectionintegral spectrum (UV-Vis DRIS).     

A pure inorganic 2-D framework based on paradodecatungstate and Mn2+ ions: syntheses,structure, and properties

A pure inorganic 2-D framework based on paradodecatungstate polyanions and [Mn(H₂O)_n]²⁺ (n = 2, 3) ions, Na₁₀{[Mn(H₂O)₃]₂[H₂W₁₂O₄₂]}{[Mn(H₂O)₃]₂[Mn(H₂O)₄][H₂W₁₂O₄₂]}·56H₂O (1), has been synthesized and characterized by IR spectra, UV–vis spectra, thermogravimetric analysis (TGA), single-crystal X-ray diffraction, and magnetic measurements. Single-crystal X-ray diffraction analysis indicates that [H₂W₁₂O₄₂]^10? in 1 is a tetradentate ligand and coordinates to four [(Mn(H₂O)₃]²⁺ cations through terminal oxygens to form manganese doubly bridged 1-D chains, which are further linked through [Mn(H₂O)₄]²⁺ ions into a 2-D layer. The catalytic activities of 1 are tested in the selective oxidation of benzyl alcohol to benzaldehyde with 30% aqueous H₂O₂ as oxidant in toluene, exhibiting 90% conversion and 93% selectivity. Magnetic studies indicate that weak antiferromagnetic couplings exist between the Mn(II) ions in 1.     

Syntheses,structures and luminescent properties of two 3D pillared open frameworks with unique 6-connected structures based on 4,5-dihydroxy-1,3-benzenedisulfonate

Two coordination polymers, [Ba(H₂L)(H₂O)]_n·nH₂O (1) and [La(HL)(H₂O)]_n·nH₂O (2) (Na₂H₂L = 4,5-dihydroxy-1,3-benzenedisulfonic acid disodium salt), have been synthesized under hydrothermal conditions. The central metal ions are nine-coordinate with distorted tricapped trigonal prismatic arrangements. Compounds 1 and 2 have 3-D metal–organic framework (MOF) structures which are created by 2-D inorganic layers [Ba₂S₂O₅]_n and [La₂S₂O₅]_n through organic phenyl moieties of HL^3? linkages. The inorganic layers and organic pillars are alternately arranged to generate the 3-D pillared-layered open frameworks with (4¹¹, 6⁴) topologies. Results of fluorescence measurements reveal that two decayed emission bands centered at 435 and 408 nm may be caused by interactions of the ligands and the metal ions. The respective luminescence emission peaks appear at different wavelengths and intensities, which can be affected by the metal ions.     

Two new hybrid compounds assembled from Keggin-type polyoxometalates and transition metal coordination complexes

Two new hybrid compounds based on Keggin-type polyoxometalates: {[PMo₁₂O₄₀][Ni(Phen)₂(H₂O)]₂}·K·2OH⁻ (1) and [Cd₂(Phen)₄Cl₂][HPW₁₂O₄₀]·H₂O (2) (Phen=1,10-phenanthroline), have been prepared and characterized by IR, UV-vis, XPS, XRD and single crystal X-ray diffraction analyses. Compound 1 exhibits a 1-D chain structure constructed from Pseudo-Keggin polyoxometalate bi-supported transition metal coordination complexes linked by K⁺ ions. Compound 2 contains Pseudo-Keggin polyoxoanions [HPW₁₂O₄₀]²⁻ and novel metal-chloride-ligand coordination complexes [Cd₂(Phen)₄Cl₂]²⁺.     

Hydrothermal synthesis and characterization of a new Anderson-type polyoxometalate

A new compound based on Anderson-type polyoxometalate, [Cu(phen)H₂O]₂[CrH₅Mo₆O₂₄]?·5H₂O (1) (phen?=?1,10-phenanthroline), has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectrum, and thermal gravimetric analysis. Luminescent, electrochemical, and electroactivity properties of 1 have been studied.     

Influence of metal ions on the structures of Keggin polyoxometalate-based solids: Hydrothermal syntheses, crystal structures and magnetic properties

Three new Keggin polyoxometalate (POM)-based compounds linked to 3d metal complexes have been synthesized under hydrothermal conditions: [Cu(phen)₂]₂{[Cu(phen)]₂ [SiMo₁₂O₄₀(VO)₂]} (1), {[Zn(phen)₂]₂[GeMo₁₂O₄₀(VO)₂]}{[Zn(phen)₂(H₂O)]₂ [GeMo₁₂O₄₀(VO)₂]}·3H₂O (2) and {[Co(phen)₂]₂[PMo₁₂O₄₀(VO)₂]}{[Co(phen)₂(OH)]₂ [PMo₁₂O₄₀(VO)₂]}·2.5H₂O (3) (phen=1,10-phenanthroline). These three compounds present, as building blocks, the bicapped Keggin anions [XMo₁₂O₄₀(VO)₂] (X=Si, Ge and P). Compound 1 consists of a bicapped Keggin anion [SiMo₁₂O₄₀(VO)₂]²⁻ linked to two [Cu(phen)]⁺ complexes with two [Cu(phen)₂]⁺ countercations. Compound 2 contains two bicapped Keggin anions [GeMo₁₂O₄₀(VO)₂]⁴⁻, one linked to two [Zn(phen)₂(H₂O)]²⁺ cations and the other one linked to two [Zn(phen)₂]²⁺ cations. Compound 3 is a two-dimensional POM-based square network formed by bicapped Keggin anions [PMo₁₂O₄₀(VO)₂]⁴⁻ connected by [Co(phen)₂]²⁺ cations. Discrete bicapped Keggin anions [PMo₁₂O₄₀(VO)₂] linked to two [Co(phen)₂(OH)]⁺ cations are located between the layers. The magnetic properties show the presence of antiferromagnetic interactions among the reduced Mo(V) atoms (in the three compounds) plus a paramagnetic contribution from the V(IV) atoms (in 1 and 2). Compound 3 shows, in addition, an antiferromagnetic interaction between the Co(II) and the V(IV) ions directly linked through an oxygen bridge. The low-temperature ESR spectra of compound 3 confirm the presence of the reduced Mo(V) ions and the antiferromagnetic coupling between the Co(II) and the V(IV) ions.     

Two-dimensional metal-organic framework constructed from 4,4′-bipydine and 1,2,4-benzenetricarboxylate: Synthesis, structure and magnetic properties

Two new copper coordination polymers generated from mixed organic ligands 4,4′-bipydine and 1,2,4-benzenetricarboxylate [Cu₃(1,2,4-BTC)₂(4,4′-bipy)(H₂O)₄] 1 and [Cu(1,2,4-HBTC)(4,4′-bipy)] 2 (1,2,4-BTC=1,2,4-benzenetricarboxylate) have been prepared hydrothermally and characterized by single crystal X-ray diffraction. Compound 1 crystallizes in the noncentrosymmetric space group Fdd2, with , , , , and Z=8. Its structure contains two different one-dimensional (1-D) chains for the Cu ions, namely and ; the carboxylate of 1,2,4-BTC ligands links the two different 1-D chains into an interesting steplike neutral framework. Compound 2 crystallizes in the monoclinic space group P2₁/n, with a=9.9806(8), b=16.5512(16), , β=99.375(5)°, , Z=4. Its structure contains novel paddle-wheel clusters Cu₂(CO₂)₄(4,4′-bipy)₂ as SBUs which are further linked by monoprotonated 1,2,4-BTC ligands into a 2-D neutral framework. The magnetic behaviors of both compounds have been studied.     

Hydrothermal Synthesis and Structure Characterization of Open-framework Cobalt-tungsten Phosphate[H3NCH2CH2NH3]3[Co3W4P4O28]

A new three-dimensional open-framework cobalt(Ⅱ)-tungsten(Ⅵ) phosphate,[H3NCH2CH2NH3]3·[Co3W4P4O28](1) has been synthesized from the reaction of CoCl2·6H2O,WO3,H3PO4,ethylenediamine and H2O.The title compound was fully characterized by infrared spectroscopy,elemental analysis,magnetic properties,thermogravimetric analysis,XPS and single-crystal X-ray diffraction.The compound crystallized in a tetragonal space group I4(1)/a with a=1.7118(4) nm,c=1.0773(2) nm,V =3.1568(11) nm3,Z =4.     

A 3-D Gd(III)–Cu(I) coordination polymer based on nicotinate and oxalate ligands: synthesis,crystal structure,and magnetic properties

A new 3d–4f coordination polymer, [GdCu(nic)₂(ox)_0.5Br(H₂O)₂] (1) [nic = nicotinate, ox = oxalate], was synthesized and characterized by elemental analysis, infrared (IR) spectroscopy, thermal analysis and single crystal X-ray diffraction. Compound 1 exhibits a 3-D network constructed from Gd-carboxylate chain, Cu(nic)₂ subunits and ox ligands. Furthermore, the magnetism is studied in this article.     

Solvothermal synthesis and crystal structure of a 3-D hexagonal metal-porphyrin coordination network

A hexagonal-shaped hybrid metal-porphyrin framework containing 5,15-di(4-pyridyl)-10,20-diphenylporphyrin (trans-H₂DPyP) and Zn(NO₃)₂6H₂O in DMF has been self-assembled solvothermally. The solvothermal reaction of Zn(II) with conformationally versatile 5,15-di(4-pyridyl)-10,20-diphenylporphyrin, which can coordinate axially to two ligands, resulted in metalation of the porphyrin core and then self-coordination of the metalated porphyrin-produced single crystals of 3-D polymeric arrays. The trans-ZnDPyP framework is thermally stable at 450?°C and allows solvent exchange without losing the crystal structure.     

Synthesis, structure, and properties of the first trimetallic phosphate [Ni(H2O)4]Cd(VO)(PO4)2 with neutral 3-D pillared-layer framework

Hydrothermal reactions of VOSO₄·3H₂O, CdAc₂·2H₂O, NiCl₂·6H₂O, H₃PO₄, and H₂O yield the first example of trimetallic phosphate materials, [Ni(H₂O)₄]Cd(VO)(PO₄)₂1. The single-crystal X-ray diffraction shows that its structure consists of Cd/V/O binary metal oxide lamellas decorated by PO₄ tetrahedra, which are further pillared by NiO₂(H₂O)₄ octahedra to generate a neutral 3-D framework containing two intercrossing 8-MR channels where the coordinated water molecules protrude into. Thermal and magnetic behaviors of this material were also measured. Crystal data: CdNiVP₂O₁₃H₈, orthorhombic Ibca (No.73), a=7.1307(2) Å, b=18.6248(3) Å, c=14.8046(2) Å, V=1966.17(7) Å³, Z=8.     

Hydrothermal synthesis, structure and thermal property of a 2-dimensional network: sodium sulfate [Ni(H2O)6(NaSO4)2]

The title compound of [Ni(H₂O)₆(NaSO₄)₂] has been synthesized under hydrothermal conditions and characterized by single crystal X-ray diffraction. The compound crystallizes in space group P2₁/c of the monoclinic system in a cell at 293.2 K of a=6.1820(12) Å, b=12.316(3) Å, c=9.0890(18) Å, β=106.03(3)°, and V=665.1(2) Å³. In the title compound, each SO₄ tetrahedron coordinates with three Na(I) ions and each Na(I) connects to three SO₄ tetrahedrons. Such a coordinate model makes up a two-dimensional network having two different kinds of rings and, in the bigger rings, the [Ni(H₂O)₆]²⁺ ions are located. In the solid state, some hydrogen bonds connect the title compound to form three-dimensional networks, stabilizing the crystal structure. Thermogravimetric analysis shows that there are three steps of weight loss from the beginning of 110 °C and the residue may be the mixtures of NiO₂ and Na₂O.     

2-(1H-pyrazol-3-yl)pyrazine: a polytopic N-donor ligand used to construct Cu-[2+2] molecular grid: synthesis,structure, and magnetic properties

Herein, we present a new polytopic N-donor, which is used to construct a metal–organic compound. The resulting metal–organic compound, Cu₄(L)₆(NO₃)₂ (HL=(1H-pyrazol-3-yl)pyrazine) (1), is synthesized by the hydrothermal reaction of Cu(NO₃)₂ and HL (ratio: 1?:?1). Single-crystal X-ray diffraction shows that 1 comprises a Cu-[2+2] molecular grid. Magnetic studies reveal antiferromagnetic interactions, interpreted by a simplified dinuclear mode.