Synthesis,structure and properties of a new copper (II) complex, [Cu2(4,4′-bpy)5(H2O)4](ClO4)4(4,4′-bpy)(DMF)2(H2O)2

A new copper (II) complex with formula [Cu₂(4,4′-bpy)₅(H₂O)₄](ClO₄)₄(4,4′-bpy)(DMF)₂(H₂O)₂ has been synthesized by reaction of 4,4′-bpyridine (4,4′-bpy) with Cu(ClO₄)₂. While strong hydrogen bonds play central roles in the formation of the 3D structure, the combined influence of the weak interactions such as C–H?O bonds, anion?π and C–H?π interactions are also evident in the structure. The preliminary investigation on the thermal property of the complex is presented.     

A novel paradodecatungstate-B compound decorated by transition metal copper,Na2Cu5(H2O)24(OH)2[H2W12O42]·10H2O: Synthesis,structure and antitumor activities

A new paradodecatungstate-B compound decorated by transition metal copper, Na₂Cu₅(H₂O)₂₄(OH)₂[H₂W₁₂O₄₂]·10H₂O (1), has been synthesized by convenient aqueous solution method and structurally characterized by single-crystal X-ray diffraction, IR spectrum, elemental analysis and TGA. The compound crystallizes in the triclinic P-1 space group with a = 10.7140(8) Å, b = 12.9476(9) Å, c = 13.6696(10) Å, α = 73.56°, β = 75.73°, γ = 67.69°, V = 1661.8(2) ų and Z = 1. In compound 1, polyanion of [H₂W₁₂O₄₂]^10 − acts as a dodecadentate ligand that links copper and sodium cations, forming a remarkable three-dimensional framework. The experiment of antitumor activities in vitro shows that the title compound exhibits remarkable inhibitory actions on human cervical carcinoma HeLa cells, ovarian carcinoma SKOV-3 cells, hepatoma HepG2 cells and neuroblastoma SHY5Y cells.     

A novel organic-inorganic hybrid polyoxometalate-based 3D framework constructed by organo-functionalized [As2W21O72(mal)2]18 − units and Ce3 + ions

A novel organic-inorganic hybrid polyoxometalate-based 3D framework K₅H₄{Ce₃(H₂O)₉[As₂W₂₁O₇₂(mal)₂]}·20H₂O (1) (mal = malic acid) has been synthesized by the metastable precursor [As₂W₁₉O₆₇(H₂O)]^14 −, which was further characterized by IR spectrum, thermogravimetric analysis (TGA), and X-ray single-crystal diffraction. Structural analysis revealed that 1 consists of the organo-functionalized [As₂W₂₁O₇₂(mal)₂]^18 − units linked together by the Ce^3 + ions resulting in 3D network-like architecture. Magnetic property studies indicate that obvious antiferromagnetic interactions exist in three Ce^3 + ions.     

Synthesis,structure and superoxide dismutase activity of a novel tetranuclear copper(II) complex Na2[Cu4Na2(TACNTA)4(H2O)6]·(H2O)26

A novel tetranuclear copper(II) complex Na₂[Cu₄Na₂(TACNTA)₄(H₂O)₆]·(H₂O)₂₆, where TACNTA is 1,4,7-triazacyclononane-1,4,7-triacetate, was synthesized and characterized by X-ray crystallography. The result shows that each copper(II) ion is six-coordinated to three nitrogen atoms and three oxygen atoms of ligand TACNTA and adopts distorted octahedral coordination geometry. The superoxide (·O₂^?) dismutation activity of the complex was also investigated by the riboflavin–methionine–nitro blue tetrazolium assay.     

Synthesis,structure, and properties of two novel copper(II) complexes, [Cu(phen)(L)2]·6H2O and [Cu(phen)3]·(ClO4)2

Two novel copper(II) complexes, namely [Cu(phen)(L)₂]·6H₂O (1) and [Cu(phen)₃]·(ClO₄)₂ (2) have been synthesized under mild condition (HL = 5-methyl-1H-pyrazole-3-carboxylic acid, phen = 1,10-phenanthroline). We report the structural evidence of discrete water decamer conformation in the solid state. These units are found to act as supramolecular glue in the aggregation of mononuclear copper(II) complex to give a three-dimensional network through hydrogen-bonding. The preliminary investigation on the thermal behavior and the anion exchange property of the complexes are presented.     

Two-dimensional cobalt-bipyridinedicarboxylate coordination polymer: [Co(2,2′-bipyridine-5,5′-dicarboxylato) (H2O)]·(H2O)

Hydrothermal reaction between cobalt(II) nitrate and 2,2^′-bipyridine-5,5^′-dicarboxylic acid in the presence of NaOAc gave a two-dimensional coordination-polymer of cobalt(II), [Co(2,2^′-bipyridine-5,5^′-dicarboxylato)(H₂O)]·(H₂O) (1). X-ray structure determination showed that compound 1 has a two-dimensional infinite network based on cobalt-bipyridinedicarboxylate building blocks and has a relatively small channel of 5.0×6.6 Å.     

Hydrothermal synthesis and structural characterization: a novel α-Keggin unit supported zinc-bipyridyl complex [Zn(2,2′-bipy)3]2[ZnW12O40Zn(2,2′-bipy)2] · H2O

The hydrothermal reaction of Na₂WO₄ · 2H₂O, ZnCl₂, Zn(Ac)₂ · 2H₂O, 2,2^′-bipyridine, and H₂O gives rise to a novel Keggin unit supported zinc-bipyridyl complex [Zn(2,2^′-bipy)₃]₂[ZnW₁₂O₄₀Zn(2,2^′-bipy)₂] · H₂O consisting of a novel heteropolyanion [ZnW₁₂O₄₀Zn(2,2^′-bipy)₂]⁴⁺ in which the Keggin anion [ZnW₁₂O₄₀]⁶⁻ acts as a bidentate ligand towards the transition metal cation Zn²⁺ through a terminal oxygen and a bridging oxygen from the same WO₆ octahedron.     

A novel 2D organic–inorganic hybrid based on [P2W18O62]6− polyoxoanion and Cu–bbi coordination polymers

A novel 2D compound based on Wells–Dawson polyoxometalates, [Cu₃(bbi)₆(P₂W₁₈O₆₂)] (bbi = 1,1′-(1,4-butanediyl)bis(imidazole)) (1) has been hydrothermally synthesized and characterized by elemental analyse, IR, TG, PXRD and single crystal X-ray diffraction. In compound 1, each Cu²⁺ ion is connected with four adjacent Cu²⁺ ions by bbi ligands along four different directions and each bbi ligand is two-coordinated by two Cu²⁺ ions, which results in an unusual 2D interlink lock-liked layer. Interestingly, two kinds of macrocycles exist in the structure, in which six smaller 33-membered rings are placed end to end to form the larger ones (66-membered macrocycles). The [P₂W₁₈O₆₂]⁶⁻ polyoxoanions as bidentate ‘guest’ is incorporated into the larger macrocycles. These 2D layers are further packed into 3D framework through strong supramolecular interactions. Additionally, electrochemical and electrocatalysis behavior of 1-CPE have been studied in detail.     

Synthesis,structure and characterization of (NH4)2[Cu2(H2O)4(NH3CH2COO)2(NH2CH2COO)2]H2V10O28·6H2O

The decavanadate with a novel glycine–glycinato complex of copper (II) in the cationic part, (NH₄)₂[Cu₂(H₂O)₄(NH₃CH₂COO)₂(NH₂CH₂COO)₂]H₂V₁₀O₂₈·6H₂O (1), has been prepared and characterized by elemental analysis, infrared and EPR spectroscopies. The triplet X band EPR spectrum of powdered sample evidenced magnetic interaction between the Cu(II) atoms in the dimeric unit which is probably realized through the bridging water molecules in this part of the complex. A single crystal X-ray diffraction study revealed that the structure of 1 contains cationic copper complex with a rare Cu(H₂O)₂Cu double bridge. In this cation, a simultaneous bidentate N, O– and monodentate O– coordination of glycine to the same central atom was observed for the first time.     

[Zn2(H2O)3(2,2′-bipy)2(btc)][Zn(H2O)(2,2′-bipy)(btc)] ·8H2O: a novel zinc–carboxylate complex consisting of independently cationic and anionic chains

A novel zinc complex, [Zn₂(H₂O)₃ (2,2^′-bipy)₂(btc)][Zn(H₂O)(2, 2^′-bipy)(btc)]·8H₂O (1), (H₃btc=1,3,5- benzenetricarboxylic acid, 2,2^′-bipy=2,2^′-bipyridine) has been prepared by hydrothermal reaction of H₃btc, Zn(CH₃CO₂)₂·2H₂O and 2,2^′-bipyridine at 180 °C and characterized by single-crystal X-ray diffraction analysis. Complex 1 consists of independently cationic and anionic chains. The hydrogen bonding interactions between chains extend 1 into a two-dimensional supramolecular architecture.     

Tetra-hafnium(IV) cluster cation sandwiched between 2 di-lacunary Dawson polyoxotungstate anions: Synthesis and structure of [Hf4(μ3-O)2(μ-OH)2(H2O)4(P2W16O59)2]14−

The title polyoxometalate (POM) 1 was obtained by a 1:2 molar-ratio reaction of tri-lacunary Dawson POM [B-α-P₂W₁₅O₅₆]^12? with Hf(SO₄)₂ or HfCl₄ in an aqueous solution, and isolated as dimethylammonium salt (Me₂NH₂-1) and, also, as sodium salt (Na-1). These compounds were unambiguously characterized by complete elemental analysis, including sodium and oxygen analyses, TG/DTA, FTIR, single-crystal X-ray structure analysis, (solid-state and solution) ³¹P NMR and solution ¹⁸³W NMR spectroscopy. X-ray crystallography revealed that 1 with C_i symmetry was composed of a tetra-Hf^IV cluster cation species [Hf₄(μ₃-O)₂(μ-OH)₂(H₂O)₄]¹⁰⁺ sandwiched between 2 di-lacunary Dawson polyoxometalates (POMs), [P₂W₁₆O₅₉]^12?, and it was isostructural with the previously reported Zr₄ analogue. Thus, a pair of Hf- and Zr-containing POMs belonging to the same structure-family was built up.     

A 2D polymer constructed through bridging oxalato and 4,4′-bipyridine ligands: crystal structure and magnetic behavior of [Cu3(μ-ox)3(μ-4,4′-bpy)2(4,4′-bpy)2]n

The crystal structure of the compound [Cu₃(μ-ox)₃(μ-4,4^′-bpy)₂(4,4^′-bpy)₂]_n 1 (ox=oxalato, 4,4^′-bpy=4,4^′-bipyridine) is comprised of two-dimensional sheets in which copper(II)–oxalato chains are cross-linked by bridging bidentate 4,4^′-bpy ligands. Metal centers show a tetragonally elongated octahedral environment formed by four oxygen atoms from two asymmetrically coordinated oxalato ligands and two nitrogen atoms from two trans-coordinated 4,4^′-bpy molecules. The magnetic measurements show the occurrence of weak ferromagnetic couplings.     

Decavanadate with a novel coordination complex: Synthesis and characterization of (NH4)2[Ni(H2O)5(NH3)]2(V10O28)·4H2O

A new compound (NH₄)₂[Ni(H₂O)₅(NH₃)]₂[V₁₀O₂₈]·4H₂O (1) containing a {V₁₀O₂₈} ⁶⁻ anionic cluster and a novel complex cation, [Ni(H₂O)₅(NH₃)]^2 +, has been synthesized and fully characterized by single crystal X-ray crystallography, spectroscopy and thermogravimetric analysis. The presence of the ammonia ligand in the complex cation in 1 was established unambiguously by X-ray crystallography and variable temperature (200–400 °C) thermogravimetric analyses in combination with FTIR spectroscopic studies. The formation of the novel complex species {Ni(H₂O)₅(NH₃)}^2 + during the synthesis of 1 can be rationalized in terms of ligand substitution involving {Ni(H₂O)₆}^2 +.     

A new organic-inorganic hybrid tetrameric polyoxometalate assembled by monovacant Dawson [α2-P2W17O61]10 − and trivalent cerium cations

A novel octa-nuclear cerium(III)-containing organic-inorganic hybrid polyoxometalate [N(CH₃)₄]₈H₁₆[{Ce(η¹-C₆H₅NO₂)₂(H₂O)₆[Ce(H₂O)₃(α₂-P₂W₁₇O₆₁)]}{Ce(η²-C₆H₅NO₂)₂(H₂O)₅[Ce(H₂O)(α₂-P₂W₁₇O₆₁)]}]₂·90H₂O (C₆H₅NO₂ = isonicotinic acid) (1) was obtained, which had been hydrothermally synthesized and characterized by IR spectrum, thermogravimetric analysis (TGA), and X-ray single-crystal diffraction. Structural analysis indicated at 1 is composed of four lacunary Dawson-type units [α₂-P₂W₁₇O₆₁]^10 − joined together by eight cerium cations forming an uncommon zigzag tetrameric structure with eight isonicotinic acids as the organic pendants coordinating to the cerium cations. Magnetic property studies indicate that obvious antiferromagnetic interactions exist in eight Ce^3 + cations.