Hydrothermal synthesis,crystal structure and fluorescence of a 3D organic–inorganic hybrid coordination network [CuI(4,4′-bipy)]4[ δ -Mo8O26] exhibiting an interesting polymorphism

A new three-dimensional (3D) extended solid [Cu^I(4,4′-bipy)]₄[δ-Mo₈O₂₆] (1) built on {Cu(4,4′-bipy)}⁺ (bipy?=?bipyridine) and isopolymolybdate anion [δ-Mo₈O₂₆]^4? has been synthesized and characterized by elemental analysis, IR, TG, X-ray powder diffraction and single-crystal X-ray diffraction analysis. Compound 1 shows six coppers bonded to [δ-Mo₈O₂₆]^4? to form inorganic planes which are linked by 4,4′-bipy into a 3D network, the first example of [δ-Mo₈O₂₆]^4? six-connected linkage based on an organic-inorganic coordination polymer. A polymorphism of compound 1 was found which has an identical molecular formula but absolutely different structure. The influence of the synthesis conditions of 1 has been studied. Furthermore, the fluorescence of 1 is reported.     

A new 1-D chain-like organic–inorganic hybrid phosphotungstate constructed by sandwich-type clusters and [Ni(en)2]2+ linkers

A new 1-D chain-like organic–inorganic hybrid phosphotungstate based on tetra-Ni-sandwiched polyoxoanion, [Ni(en)₂]₂[{Ni₃(en)₆(H₂O)₂Ni₄(H₂O)₂(α-PW₉O₃₄)₂}]?·?7H₂O (en?=?ethylenediamine) (1), has been synthesized under hydrothermal conditions and characterized by IR spectrum, UV spectrum, elemental analysis, thermogravimetric analysis, and single-crystal X-ray diffraction. 1 crystallizes in the triclinic P 1 space group with cell parameters a?=?13.232(4)?Å, b?=?15.591(5)?Å, c?=?15.701(5)?Å, α?=?112.804(5)°, β?=?92.159(5)°, γ?=?109.012(5)°, Z?=?1, R ₁?=?0.0588, wR ₂?=?0.1387. Compound 1 displays a 1-D chain-like architecture constructed by sandwich-type polyoxoanions and [Ni(en)₂]²⁺ linkers. Magnetic measurement reveals that intramolecular ferromagnetic interactions exist in the tetranuclear {Ni₄O₁₆} cluster.     

Two organic–inorganic hybrid compounds constructed from 12-tungstovanadate and bipyridine

Two rare 12-tungstovanadate-bipyridine inorganic–organic hybrid compounds, [VW₁₂O₄₀] · 2(4,4′-H₂bipy) · 2H₂O (1) and [VW₁₂O₄₀] · 4(2,2′-Hbipy) (2), have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction and IR analysis. In 1, a 2-D supramolecular architecture is formed by hydrogen-bonding between [VW₁₂O₄₀]^4? and bipy. Compound 1 shows good activity for photocatalytic reduction of rhodamine B in a liquid–solid system. The electrochemical and electrocatalytic properties of 2-bulk carbon paste electrode modified with 2 were investigated by cyclic voltammetry.     

A novel inorganic–organic hybrid compound constructed from copper(II)-monosubstituted polyoxometalates and poly(amidoamine)

A novel inorganic–organic hybrid compound constructed from copper(II)-monosubstituted polyoxometalate Na₅PW₁₁Cu(H₂O)O₃₉ (PW₁₁Cu) and poly(amidoamine) (PAMAM) dendrimer was prepared at room temperature in an aqueous solution. The title compound PW₁₁Cu/PAMAM was characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction, indicating that the PW₁₁Cu was chemically anchored to PAMAM. The compound was first used as a bulk-modifier to fabricate a chemically modified carbon paste electrode (CPE) by direct mixing. The PW₁₁Cu/PAMAM bulk-modified CPE showed well-defined cyclic voltammograms with four redox couples in 0.2 M NaAc buffer solution and high electrocatalytic activity for the reduction of hydrogen peroxide and nitrite. Furthermore, the CPE revealed good stability due to the insolubility of the title compound and the interaction between PW₁₁Cu and PAMAM.     

A 3-D inorganic–organic hybrid based on saturated Wells–Dawson polyoxoanion and K+, linked by an Ag–Ag bond

A 3-D complex K₂[Ag₂(biim)₂]₂P₂W₁₈O₆₂ (biim?=?biimidazole) (1) has been hydrothermally synthesized and characterized by IR, thermogravimetric, and single-crystal X-ray diffraction. Single-crystal X-ray structural analysis reveals that 1 exhibits a 1-D wavelike chain constructed from µ₃-bridging oxygen atoms of [P₂W₁₈O₆₂]^6? and [Ag₂(biim)₂]²⁺. The K⁺ link to six oxygen atoms of three P₂W₁₈ clusters and 12 equatorial terminal oxygen atoms of P₂W₁₈ clusters link to six K⁺, resulting in a 3-D framework with a relatively short Ag–Ag bond [2.836?Å]. The electrochemical behavior of 1 modified carbon paste electrode (1-CPE) has been studied. The results indicate that 1-CPE has remarkable stability.     

Synthesis,characterization and electrochemical investigation of a new inorganic–organic hybrid compound constructed by Keggin-type polyoxometalate and cyanoguanidine

An inorganic–organic hybrid complex [HDCD]₃[PW₁₂O₄₀]·3H₂O (1) (DCD = 2-cyanoguanidine) has been synthesized from the reaction of Keggin polyanion and cyanoguanidine (C₂N₄H₄) under mild condition, and characterized by using elemental analysis, infrared spectrum, thermogravimatric analysis and single crystal X-ray diffraction. X-ray crystallography reveals that 1 displays an inorganic–organic hybrid frameworks constructed by [PW₁₂O₄₀]³⁻ Keggin-type polyoxoanion and three {(HDCD)}⁺ monocationic hydrogen-bonded units. The electrochemical behavior and electrocatalysis of 1 have been studied in detail.     

A new organic–inorganic hybrid based on Mn–salen and decavanadate

An organic–inorganic hybrid based on Mn-salen and decavanadate, [NH₄]₂[Mn(salen)(H₂O)₂]₄[V₁₀O₂₈]?·?6H₂O (1) (salen?=?N,N′-ethylene-bis(salicylideneiminate)), has been synthesized by the strategy of secondary building units in mixed methanol–water solution and was structurally characterized by single-crystal X-ray diffraction, elemental analyses, IR, and UV-Vis. The [Mn(salen)(H₂O)₂]⁺ cations and water molecules are located in the interspaces among the polyoxoanions [V₁₀O₂₈]^6? forming a POM-based supramolecule. Compound 1 is the first example of metal-Schiff-base polyoxovanadates. The photocatalytic analysis, cyclic voltammetry, and electrocatalytic analysis of 1 have been investigated.     

A new organic-inorganic hybrid material constructed from Keggin polyanion and transition metal complexes: [Co(2,2′-bipy)3]1.5[SiWVWVI 11O40Co(2,2′-bipy)2(H2O)] · 0.5H2O

A new organic-inorganic hybrid compound constructed from Keggin-type polyanion clusters and transition metal complexes, [Co(2,2′-bipy)₃]_1.5[SiW^VW^VI ₁₁O₄₀Co(2,2′-bipy)₂(H₂O)] ·?0.5H₂O (1), has been hydrothermally prepared and characterized by elemental analysis, IR, UV–Vis, TG-DTA and single crystal X-ray diffraction. Compound 1 crystallized in the monoclinic system, space group C2/c, a =?46.995(15), b =?14.487(5), c =?26.205(9)Å, β =?90.000(0)°, V =?17841(10)ų, Z =?4. Compound 1 contains a [SiW^VW^VI ₁₁O₄₀Co(2,2′-bipy)₂(H₂O)]^3? polyoxoanion in which [Co(2,2′-bipy)₂(H₂O)]²⁺ is covalently bonded to the α-Keggin-type heteropolyanion [SiW^VW^VI ₁₁O₄₀]^5? via a terminal oxygen.     

Synthesis and properties of two new 3D organic–inorganic hybrid compounds constructed from Keggin clusters,pyridine-2,3-dicarboxylate and Ag(I) ions

Two new three-dimensional (3D) organic–inorganic hybrid compounds [K₂Ag₈(pydc)₂(Hpydc)₂(H₂O)₄SiW₁₂O₄₀]·4H₂O (1) and (NH₄)₄[KAg₂(Hpydc) (H₂O)_4.5(H₂W₁₂O₄₀)]·4H₂O (2) [H₂pydc = pyridine-2,3-dicarboxylate], were conventionally synthesized and characterized by IR, TG, elemental analysis, and single-crystal X-ray diffraction technique. In 1, six-nucleus [Ag₆(Hpydc)₂]⁴⁺ and two-nucleus [Ag₂(pydc)₂]²⁻ are linked alternately through oxygen atoms of the carboxylic group leading to a grid-like 2D layer. These layers are supported by SiW₁₂ clusters, giving a unique 3D framework. In 2, each W₁₂ cluster connects five Ag ions and three K ions, and each Ag1 or Ag2 ion links three W₁₂ clusters, forming a double chain. Furthermore, these double chains are linked together through K⁺ ions to form a 3D framework. The solid-state luminescence properties of compounds 1, 2 and pyridine-2,3-dicarboxylate have been studied at room temperature.     

Synthesis and characterization of two novel organic–inorganic hybrid solids from Keggin ions and metal coordination complexes

Two new hybrid compounds, [Co(4,4′-bpy)₂(H₂O)₄][(4,4′-bpyH₂]₂[CoW₁₂O₄₀]·8H₂O (1) and [Fe(2,2′-bpy)₃]₃[H₂W₁₂O₄₀]·6H₂O (2), (4,4′-bpy = 4,4′-bipyridine, 2,2′-bpy = 2,2′-bipyridine) have been hydrothermally synthesized. These solids were characterized by elemental analysis, thermogravimetric analysis, UV–Vis spectroscopy and X-ray diffraction. The hydrogen-bonding interactions in 1 lead to the formation of a three dimensional network consisting of [CoW₁₂O₄₀]⁶⁻ anionic clusters, [Co(4,4′-bpy)₂(H₂O)₄]²⁺ cations and lattice water molecules, while the discrete Keggin ion [H₂W₁₂O₄₀]⁶⁻ in compound 2 is surrounded by 14 [Fe(2,2′-bpy)₃]²⁺ complexes through CH?O interactions (2.24–2.56 Å).     

Synthesis and structural reactivity of inorganic–organic hybrid nanocomposites – A review

Chemistry of hybrid nanocomposites depends mainly on their reactivity and structural relationship. This review mainly reports on the processing techniques of inorganic–organic hybrid nanocomposites and their natural reactivity. Herein, the structure, processing methods and properties of nanocomposites with three different types of matrices are discussed in general. The perusal of this review enables the researchers to design a novel and simple route in processing the hybrid nanocomposites.     

Design and synthesis of two-dimensional pillared MOF layers by connecting infinite one-dimensional chains via 4,4′-bipyridine

Two novel metal-organic frameworks, [Cd(Bna)(DMF)₂(H₂O)₂] _n · nDMF (I) (Bna = 2,2′-dihydroxy-l,l′-dinaphthyl-3,3′-dicarboxylate) and [Cd(Bna)(Bipy)(DMF)₂] _n (II) (Bipy = 4,4′-bipyridine) have been synthesized under mild conditions and structurally characterized. Crystal structural analyses reveal that complex I adots a 1D spiral structure with DMF guest molecules in the spiral by hydrogen bondings. Complex II is constructed by -Cd-Bna-Cd- zigzag chains, which are further connected by Bipy into a 2D sheet. X-ray powder diffraction and thermogravimetric analyses for I and II show that they are highly themally stable in the solid state.     

Photoregulated uptake and release of drug by an organic–inorganic hybrid sol–gel material

A photo-responsive molecularly imprinted sol–gel organic-inorganic hybrid material prepared by covalent imprinting of the template-functional monomer complex formed between 4,4′-dihydroxylazobenzene and ibuprofen was developed to explore the photo-regulated uptake and release of drug by a silicate-based smart molecularly imprinted materials. After imprinting, the template molecules (ibuprofen) were removed via hydrolysis in acid, and accurate cavities were left, which could be used as the receptor recognition sites for ibuprofen. The new organic–inorganic hybrid material shows specific affinity to ibuprofen and reversible uptake and release of ibuprofen upon alternate irradiation at 365 and 440 nm, respectively. The favorable binding strength of the imprinted receptor sites in the molecularly imprinted polymer (MIP) for ibuprofen is found to be 2.28 × 10³ M⁻¹. Density of receptor sites in the MIP material was 4.0 μmol/g—MIP.     

A new organic–inorganic heteropolyoxometalate compound [Co(2,2′-bipy)3]H[Al(OH)6(Mo6O18)]·17H2O based on B-Anderson–Evans type polyanion (2,2′-bipy=2,2′-bipyridine)

A new organic–inorganic polyoxometalate compound [Co(2,2′-bipy)₃]H[Al(OH)₆ (Mo₆O₁₈)]?·?17H₂O has been synthesized and characterized by elemental analysis, IR, UV spectra, thermogravimetry and differential thermal analysis (TG-DTA) and single-crystal X-ray diffraction analysis. The title compound crystallizes in a monoclinic, C2/c space group, with a?=?37.292(8), b?=?14.214(3), c?=?25.050(5)?Å, β?=?120.62(3), V?=?11426(4)?ų, Z?=?8, F(000)?=?7200, D _c?=?2.116?Mg?m^?3, R?=?0.0748, wR ₂?=?0.1853. Crystal structural analysis indicates that the asymmetric unit in the crystal structure of the title compound consists of one B-Anderson–Evans type heteropolyoxoanion, one octahedral [Co(2,2′-bipy)₃]²⁺ coordination cation, seventeen water molecules of crystallization and a proton based on charge balance. The curves of TG-DTA indicate that weight loss of the title compound is divided into three stages. The third weight loss reveals that the backbone of heteropolyoxoanion decomposes at 744°C.     

A new organic–inorganic hybrid polyoxoniobate based on Lindqvist-type anion and nickel complex

A new organic–inorganic hybrid polyoxoniobate (H₂en)₂[Ni(en)₃][H₂Nb₆O₁₉] · 5.5H₂O (1) (en = ethylenediamine) has been synthesized by the diffusion method and structurally characterized by elemental analyses, infrared spectrum, ultraviolet (UV) spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction, thermogravimetric (TG) analysis, and single-crystal X-ray diffraction. Crystal structure analysis reveals that 1 exhibits a 3-D supramolecular architecture constructed from Lindqvist-type [H₂Nb₆O₁₉]^6? polyoxoanions and [Ni(en)₃]²⁺ via hydrogen-bonding interactions. The XPS measurement indicates that the oxidation state of Ni is +2. TG curve of 1 exhibits two steps of weight loss. In situ UV spectra display that 1 can exist in large pH range in aqueous solution.     

Three inorganic–organic hybrid compounds based on Keggin polyoxometalate and transition metal complexes: crystal structures and electrochemical properties

Polyoxometalate (POM)-based coordination polymers, [Cu(L)₂][SiW₁₂O₄₀]·4py·H₂O (1), [Ag(py)₂]₄[SiW₁₂O₄₀] (2) and [Co(L)₃]₂[SiW₁₂O₄₀]·py·7H₂O (3) (L?=?pyridine-2-carboxylic acid, py?=?pyridine), have been obtained hydrothermally and characterized by elemental analyses, IR and single-crystal X-ray diffraction analyses. Electrochemical properties are also investigated.     

Synthesis,structures and electrochemical properties of four organic–inorganic hybrid polyoxometalates constructed from polyoxotungstate clusters and transition metal complexes

Four novel organic–inorganic hybrid compounds [Cu₅ ^I(4,4′-bpy)₃(2,2′-bpy)₄][BW₁₂O₄₀] · H₂O (1), [Ni_0.5(2,2′-bpy)_1.25][Ni(2,2′-bpy)₃][Ni(2,2′-bpy)₂(H₂O)(SiW₁₁^VIW^VO₄₀)] · 0.5H₂O (2), [H₂bpy]₂[Zn(2,2′-bpy)₃]₂[Si₂W₁₈O₆₂] · 1.5H₂O (3) and [Cu^II(2,2′-bpy)₂]₂[SiW₁₂O₄₀] · 2H₂O (4) (2,2′-bpy = 2,2′-bipyridine, 4,4′-bpy = 4,4′-bipyridine) have been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, thermal gravimetric analysis, electrochemical measurements and single-crystal X-ray diffraction. Compound (1) is a novel [BW₁₂O₄₀]⁵⁻ polyoxoanion bisupported by copper(I) coordination cations with mixed 2,2′-bpy and 4,4′-bpy ligands. Compound (2) is constructed from the [SiW₁₁^VIW^VO₄₀]⁵⁻ polyoxoanions supported by [Ni(2,2′–bpy)₂]²⁺. Compound (3) is composed of a novel [Si₂W₁₈O₆₂]⁸⁻ cluster and [Zn(2,2′–bpy)₃]²⁺ complexes, which held together into a three-dimensional (3D) supramolecular network through hydrogen-bonding interactions. Compound (4) shows a 2D layer framework constructed from a bisupporting Keggin polyoxoanion cluster and [Cu(2,2′–bpy)₂]²⁺ coordination polymer fragments, resulting in 3D networks via supramolecular interactions. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

A series of new hybrid compounds constructed from Dawson-type phosphomolybdates and metal–organic coordination complexes

In this study, a series of compounds based on Dawson-type phosphomolybdates, H₃(C₆NO₂H₆)₂[K(H₂O)₃(C₆NO₂H₅)₃][P₂Mo₁₈O₆₂] ? 5.5H₂O (1), (C₆NO₂H₆)₆[Ln(H₂O)₇(C₆NO₂H₅)₂]₂[P₂Mo₁₈O₆₂]₂·13.5H₂O (Ln = Ce (2), La (3)) have been synthesized and characterized by elemental analysis, IR and UV-Vis spectroscopy methods, TG analysis, and single-crystal X-ray diffraction. Compound 1 consists of [P₂Mo₁₈O₆₂]^6? building units joined by potassium-pyridine-3-carboxylic acid complexes, resulting in a wavelike polyoxometalate (POM) chain, which further interacts with each other via intermolecular interactions to form a 3-D supramolecular channel framework containing guest water molecules. Compounds 2 and 3 possess a 3-D supramolecular framework with 1-D tunnel constructed from [P₂Mo₁₈O₆₂]^6? and mononuclear lanthanide coordination complex fragments. To the best of our knowledge, 1 not only represents the first example of 1-D hybrid assembly based on Dawson-type phosphomolybdate, but also the first hybrid compound constructed from Dawson-type POMs and alkali–metal coordination complex fragments.