Hydrothermal synthesis and crystal structural characterization of two new modified polyoxometalates constructed of positive and negative metal–oxo cluster ions

Two new interesting polyoxometalate derivatives 1 and 2 constructed of modified metal–oxo cluster ions carrying positive and negative changes, respectively, was hydrothermally prepared and structurally characterized by IR, ESR, XPS, elemental analysis and X-ray crystallography. The result of structure determination shows that compound 1 and 2 are isostructural and both contain polyoxocation and polyoxoanion, and both cation and anion are built on mixed Mo–V tetra-capped pseudo-Keggin units with P centre, [Mo₈V₈O₄₀(PO₄)]ⁿ⁻, bonded to four or two [Ni(2,2′-bipy)₂H₂O]²⁺ complexes, respectively, via terminal oxygen of the capping V atoms. Magnetism measurement indicates that there exists antiferromagnetic interaction in complex 1 and 2.     

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.     

Insertion-release of guest species and ionic conduction in polyoxometalate solids with a layer-like Anderson structure

The precipitation of Na⁺ and K⁺ mixed salts of Anderson type [SbW₆O₂₄]⁷⁻ by addition of excess of NaNO₃ and NaCl yielded polycrystalline powders of Na_2.5K_5.3[SbW₆O₂₄](NO₃)_0.8·12H₂O (1) and Na₂K_5.35[SbW₆O₂₄]Cl_0.35·12H₂O (2), respectively. The two compounds are isomorphous and exhibit a layer-like Anderson (LLA) type structure, which consists of [SbW₆O₂₄]⁷⁻-containing layers and interstitial Na⁺, K⁺, NO₃⁻ or Cl⁻, and water O atoms. Recrystallization of 1 and 2 from hot water yielded Na₂K_5.4[SbW₆O₂₄](NO₃)_0.4·12H₂O (1-recry) and Na₂K_5.25[SbW₆O₂₄]Cl_0.25·12H₂O (2-recry) as a result of partial release of NO₃⁻ and Cl⁻ (and Na⁺ and K⁺ for charge compensation). Dehydration of 1 and 2 at 400 and 500 °C (1-dehyd400 and 2-dehyd500) caused a shrinkage of lattice, but their the LLA structures retained. Simulation of X-ray diffraction (XRD) patterns for the dehydrated forms allowed to presume that the each [SbW₆O₂₄]⁷⁻ anion had been 30°-rotated within its molecular plane in order to avoid intermolecular repulsion. A compressed powder of 1-dehyd400 exhibited fast alkaline-ion conduction with a bulk conductivity of 1.2×10⁻² Ω⁻¹ cm⁻¹ at 400 °C. The hosting of a sufficient amount of NO₃⁻ together with Na⁺ for charge compensation into the lattice is crucial for high conduction.     

Hydrothermal synthesis, characterization and fluorescence property of a novel layered fluorinated gallium phosphite with heptameric building unit

A new fluorinated gallium phosphite, Ga₃F₂(2,2′-bipy)₂(HPO₃)₂(H_1.5PO₃)₂1, which is the first layered gallium phosphite with neutral framework, has been hydrothermally synthesized in the presence of 2,2′-bipyridine (2,2′-bipy) acting as a ligand. The as-synthesized product was characterized by single-crystal X-ray diffraction, powder X-ray diffraction, IR spectroscopy, thermogravimetric analysis (TGA), ICP-AES and elemental analyses and fluorescent spectrum. Single-crystal X-ray diffraction analysis reveals that compound 1 crystallizes in the monoclinic space group C2/c (No. 15) with cell parameters a=17.633(3) Å, b=9.883(2) Å, c=16.793(3) Å, β=109.88(3)°, V=2752.1(9) Å³ and Z=4. The construction of two-dimensional (2D)-layered structure in compound 1 may be viewed as the assembly of heptameric building unit, which is the first to be found in gallium phosphate/phosphite. The heptameric building unit exists in two types of configuration, which alternately connect through oxygen atoms from HPO₃ pseudo-pyramids to form a layer with 10-membered ring windows viewed along the a-axis. The adjacent layers are stably packed together and exhibit interesting three-dimensional (3D) supramolecular array via π-π interactions of the 2,2′-bipy groups. Additionally, compound 1 shows strong fluorescent property in solid state at room temperature.     

Hydrothermal Synthesis, Structural Characterization and Properties of Mixed Valent Decavanadium Oxide [Co_2Cl_8V_(10) O_(18)(H_2O)]Cl_2·6H_2O with Novel Three-dimensional Framework

IntroductionPolyoxometalates constitute an enormous classof compounds whose unusual versatility and reac-tivity afford practical applications to many fields,such as catalysis,biology,medicine,and materialsciences[1— 4] .In recent years,hydrothermal tech-nique has become a vital tool in self- assemblychemistry.This technique,in combination with or-ganic templates,has been demonstrated to be wellsuited for the synthesis and the crystal growth ofpolyoxometalates with novel structures[5— 9] .Amo…     

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.     

Hydrothermal Synthesis and Crystal Structure of a Bivanadyl Capped Keggin Polyoxomet alate[Zn(2,2''''-bpy)_2(H_2O)]_2[HPMo_(12)O_(40)(VO)_2]

1 INTRODUCTION The design and synthesis of organic-inorganic hy-brid compounds are of great interest owing to theirextensive theoretical and practical applications in ca-talysis, medicine, analytical chemistry, nanotechno-logy, electrochromism, magnetism and photochemis-try[1～5]. In heteropolyoxometalate chemistry, a newadvance is the decoration of polyoxoanions with va-rious organic and transition metal complex moieties.In contrast to a large number of known organic andtransition-metal-s…     

Hydrothermal Syntheses and Characterization of Two 1D Chain Complexes and Tetra-capped Keggin Clusters

Two new compounds, [Ni(en)₂]{[Ni(en)₂]₂[Mo^VI₆Mo^V₂V^IV₈O₄₀(SiO₄)]}[(NH₂)₂(C₂H₄)₂NH]·2H₂O(1) and [Ni(en)₂]{[Ni(en)₂]₂[Mo^VI₅Mo^V₃V^IV₈O₄₀(VO₄)]}(en)·H₂O(2)(en=ethylenediamine), have been hydrothermally synthesized and characterized by elemental analysis, infrared(IR), X-ray photoelectron spectroscopy(XPS), electron spin-resonance(ESR) and thermogravimetric(TG) analysis and single-crystal X-ray diffraction(XRD) analysis. Both the compounds exhibit a 1D chain composed of bi-supporting tetra-capped Keggin clusters and nickle coordination fragments. The 1D chains are further assembled into a 3D supramolecular network with different packing modes via hydrogen bonds. The magnetic susceptibility of compound 1 demonstrates the presence of antiferromagnetic interactions.     

新型化合物[Ni(en)3]2[Ni(en)2(H2O)2][As6V15O42]·4H2O晶体的水热合成与表征

金属氧酸盐因其在医药临床、工业催化、功能材料等方面的广泛应用而引起人们的关注[1～6], 其中, 有关钒化学的研究一直很活跃, 钒具有与钼、钨明显不同的结构特性, 钒可以采取VO4, VO5和VO6方式配位, 同时, 钒的价态可以是+3, +4和+5价. 由于钒可采取多种配位方式及多种价态, 与钼酸盐和钨酸盐相比, 钒酸盐更具有结构柔顺性, 同时易形成低价或混合价态物种.在以往的文献中, 有关P-V-O体系多金属氧酸盐的水热合成的研究已有大量的报道[7], 在常规溶液合成中, 人们已对As-V-O体系进行了相对深入的研究, 而有关水热合成的研究报道却很少, 已见报道的砷钒化合物有K6*6H2O[8,9], 4-[10], 6-[11](X=SO2-3, SO2-4, H2O). 为了探究水热条件下As-V-O体系的反应特性, 我们开展了这方面的研究工作, 并取得了突破性进展. 本文采用中温水热技术合成了含有机基团的砷矾超分子化合物2**4H2O, 探讨这类化合物的非线性光学性质、催化性质及其它功能特性将是一个非常有意义的研究领域.     

Hydrothermal syntheses and characterizations of two new hydrogen bond-supported supramolecular compounds based on polyoxometalates

Two new polyoxometalates [HN(C₂H₅)₃]₃[PMo₁₂O₄₀] (1) and [NH₂(C₂H₄NH₃)₂]₂[Mo₅P₂O₂₃] (2) have been hydrothermally synthesized and characterized by IR, UV-Vis, XPS spectra, TG analyses, and single crystal X-ray diffraction. Crystal data for 1: monoclinic, space group C2/c, a = 24.651(5) Å, b = 10.822(2) Å, c = 22.413(5) Å, β = 120.37(3)°, and V = 5158.7(18) ų; for 2: triclinic, space group P-1, a = 9.821(2) Å, b = 9.948(2) Å, c = 14.687(3) Å, α = 95.490(3)°, β = 98.870(3)°, γ = 95.710(3)°, and V = 1401.7(5) ų. The crystal structure analyses reveal complex hydrogen bonds in both 1 and 2 in 3-D supramolecular arrays constructed from different polyoxoanions and organic ligands.     

新颖的[CuI(dpq)2]+配合物阳离子修饰的砷钒酸盐[Cu(dpq)2]4[As8V14O42(H2O)]·2H2O的水热合成与结构表征

采用水热方法制备了一个新颖的[CuI(dpq)2]+配合物阳离子修饰的砷钒酸盐[Cu(dpq)2]4[As8V14O42(H2O)]·2H2O, X射线单晶衍射结果表明, 该化合物的结构是由4个[CuI(dpq)2]+阳离子和1个[As8V14O42(H2O)]4-簇阴离子以及2个结晶水组成的, 簇阴离子内部包含一个孤立的水分子.     

Two new hydrogen bond-supported supramolecular compounds assembly from tungsten-vanadium polyoxoanions and copper complex fragments

Two new supramolecular compounds based on tungsten-vanadium polyoxoanions formulated as [Cu(2,2′-bipy)₃]₂H₁₄[PW_2.2V_9.8O₄₀(VO)₂[Cu(2,2′-bipy)₂H₂O]₂][PW_2.2V_9.8O₄₀(VO)₂]·10H₂O (1) and [Cu₄(2,2′-bipy)₄(H₂O)₂(PO₄)₂]H_6.5[PW_8.4V_3.6O₄₀]·2H₂O (2) (2,2′-bipy=2,2′-bipyridine) have been synthesized hydrothermally and characterized by IR, TG, XPS and X-ray diffraction analyses. Crystal structure analyses reveal that compounds 1 and 2 exhibit novel 2D supramolecular layer structures constructed from tungsten-vanadium polyoxoanions and different types of secondary building units (SBUs), respectively, the different SBUs are formed by [Cu(2,2′-bipy)₂H₂O]²⁺ and [Cu(2,2′-bipy)₃]²⁺ cations in compound 1 and [Cu₄(2,2′-bipy)₄(H₂O)₂(PO₄)₂]²⁺ cations in 2, respectively. Study of magnetic properties indicated the presence of antiferromagnetic behaviors for both compound 1 and 2.     

The Role of Hydrothermal Synthesis in Preparative Chemistry

“Hydrothermal synthesis” usually refers to heterogeneous reactions in aqueous media above 100°C and 1 bar. The previously common distinction between hydrothermal conditions below and pneumatolytic conditions above the critical point is no longer made, since no discontinuities are observed upon exceeding the critical conditions. Under hydrothermal conditions, reactants otherwise difficult to dissolve go into solution as complexes, in whose formation water itself or very soluble “mineralizers” can participate. Thus, one can obtain the conditions of chemical transport reactions,^[1] of which hydrothermal syntheses can be considered a special case. During recent decades in the geological sciences—in which the method is also historically rooted—it has received a strong impulse, whose effect on preparative solid state chemistry is discussed here.     

Organic-inorganic hybrids constructed by Anderson-type polyoxoanions and copper coordination complexes

Four organic-inorganic hybrid compounds based on Anderson-type polyoxoanions, namely, {[Cu(2,2′-bpy)(H₂O)₃]₂[Cr(OH)₆Mo₆O₁₈]}{[Cu(2,2′-bpy)(H₂O)Cl][Cu(2,2′-bpy)(H₂O)(NO₃)][Cr(OH)₆Mo₆O₁₈]}·18H₂O (1), [Cu(2,2′-bpy)(H₂O)₂Cl]{[Cu(2,2′-bpy)(H₂O)₂][Cr(OH)₆Mo₆O₁₈]}·4H₂O (2), (H₃O){[Cu(2,2′-bpy)(H₂O)₂]₂[Cu(2,2′-bpy)(H₂O)]₂}[Cr(OH)₆Mo₆O₁₈]₃·36H₂O (3), and (H₃O){[Cu(2,2′-bpy)(H₂O)₂]₂[Cu(2,2′-bpy)(H₂O)]₂}[Al(OH)₆Mo₆O₁₈]₃·33H₂O (4), were isolated by conventional solution method, and crystal structures have been determined by single-crystal X-ray diffraction. Among them, compound 1 displays a discrete supramolecular structure, compound 2 shows a chainlike structure with chloro-copper complexes as counteranions, and compounds 3 and 4 are isomorphic and exhibit unique 3D open frameworks with lattice water molecules residing in the channels. The compounds 3 and 4 represent the first example of 3D organic-inorganic hybrid compounds in the TMs/2,2′-bpy/POMs system. Investigation of the reaction conditions reveals that the geometry and size of the anions together with its coordinating abilities to the metal centers have a decisive influence on both the composition and the dimensionality of the final compounds.     

α-(+)-Co(en)3V3O9*H2O的合成与表征

由于聚氧酸盐在催化、制药和阳离子电极等方面具有潜在的应用价值[1～3], 因此一直是无机化学研究的热点[4～8], 自1993年具有双螺旋结构的化合物[(CH3)2NH2]K4[V10O10(H2O)2(OH)4(PO4)7]*4H2O[9]被合成以来, 更多的关注集中在聚氧酸盐的合成及结构研究中.     

新颖的[Cu~I(dpq)_2]~+配合物阳离子修饰的砷钒酸盐[Cu(dpq)_2]_4[As_8V_(14)O_(42)(H_2O)]·2H_2O的水热合成与结构表征

多金属氧酸盐由于其具有独特的化学结构、特殊的电学、光学和磁学性质以及在催化和医药领域中的应用价值而成为多学科交叉研究的热点课题[1～4].球状的含有低氧化态AsⅢ和VⅣ组分的[As8V14O42(H2O)]4-多阴离子是多金属氧酸盐系列中的一个重要成员,但迄今为止,只有少数此类化合物被报道[5～7].目前,选用新奇的配合物阳离子来修饰多阴离子已被证实是一种构筑具有独特结构的多金属氧酸盐杂化材料的有效方法[8,9].由于dpq(dipyrido[3,2-d:2′,3′-f]quinoxaline,结构见图1)Fig.1Structure of dipyrido[3,2-d:2′,3′-f]quinoxaline(dpq)配体…     

[M(2,2'–bpy)2]2SiW12O40（M=Mn,Co;bpy=联吡啶）的合成、结构及其电催化水产氧性能

用水热法合成了过渡金属联吡啶配阳离子硅钨杂多酸:[M(2,2’-bpy)2]2SiW12O40(M=Mn(1)和M=Co(2)),采用红外光谱、元素分析、热重和单晶X射线衍射对其进行了表征。结果表明,化合物1和2是异质同构体,具有二维格子框架结构。初步研究了2种化合物的电催化H2O析出O2性能,发现化合物1对电催化H2O析出O2有一定的催化作用。     

Synthesis and characterization of a new dimeric polyoxometalate based on Anderson-type polyoxoanions and a trinuclear lanthanide coordination complex

An unusual compound, H₅[(C₆NO₂H₄)₄(H₂O)₁₅Nd₃][IMo₆O₂₄]₂·13.5H₂O (1) has been synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA), and single crystal X-ray diffraction. Compound 1 consists of two [IMo₆O₂₄]^5? units joined by a trinuclear neodymium-pyridine-4-carboxylic acid complex, resulting in a dimeric polyoxometalate, which further interact via weak intermolecular interactions to form a three-dimensional supramolecular framework with channels. To the best of our knowledge, no analogous dimeric polyoxometalate structure composed of an Anderson-type polyoxometalate has been reported in the literature.