Isomerization and Antiacidolysis Properties of Molybdic Heteropoly Blues with Keggin Structure

For eight kinds of acidic potassium salts of hetcropoly blues which have not been reported in literature,the isomeri/.ation reaction in solution for these two-and four-electron hcteropoly blue solids were investigated by means of polarograms,cyclic voltammetry,31P NMR and X-ray diffraction methods.The heteropolynier of PMo12 and AsMo12 converte to their β-isomers during isomerization reaction which were found to have antiacidolysis property.

SYNTHESIS AND STRUCTURE OF TWO-ELECTRON HETEROPOLY BLUE K_2H_4SiMo(Ⅴ)_2Mo(Ⅵ)_(10)O_(40)·12H_2O WITH α-KEGGIN STRUCTURE

The single crystal of two-electron heteropoly blue with Si as the heteroatom and α-Keggin structure K_2H_4SiMo(Ⅴ)_2Mo(Ⅵ)_(10)O_(40)·12H_2O was obtained by electrolytic reduction. It crystallizes in a triclinic system with space group P , Mr=2117.73, a= 13.702(4), b=14.107(3), c=14.184(2) ; α=119.27(1), β=93.14(2), ;γ=110. 3(2)°, V=2154.29~3, Z=2, F(000)=1999, μ=36.39cm^(-1), Dc=3.26 g/cm^3. Final R factor is 0.0515. Mo(Ⅴ) is situated in two different edge-shared Mo_3O_(13) groups. The heteropoly blue was characterized by IR, UV, polarography, X-ray photoelectron spectra and ESR. All the results show that the structure of the heteropoly anion with Keggin structure remains unchanged basically in the process of reduction.

Hydrothermal Synthesis and Crystal Structure of a Novel Composite Keggin-type Arsenotungstate: [Ni(phen)_2][Hphen](AsW_(12)O_(40))

A novel polyoxometalate-based composite compound [Ni（phen）2][Hphen]（AsW12040） （phen = 1,10-phenanthroline） I has been hydrothermally synthesized and characterized by elemental analysis, IR, TGA, ESR spectroscopy and single-crystal X-ray diffraction. Each structure unit of 1 consists of one polyoxoanion AsW12O40^3-, one free phenanthroline molecule and one coordination cation [Ni（phen）2]^2＋. The title compound crystallizes in the orthorhombic system, space group F212121, with a = 12.2383（7）, b = 21.0884（11）, c = 22.3237（12） A, V= 5761.4（5） A^3, Mr = 3520.44, Z = 4, Dc = 4.059 g/cm^3, F（000） = 6204, g（MoKα） = 24.844 mm^-1, GOF = 1.022, the final R = 0.0376 and wR = 0.0742 （I 〉 2σ（I）） for 865 parameters and 9637 observed reflections with I 〉 2σ（I）.

Synthesis,Structure and Properties of α-Keggin-type of K_(6)H_(3)[ZnW_(11)O_(40)Al]·9.5H_(2)O

A new heteropolycomplex, K 6H 3[ZnW 11 O 40 Al]·9 5H 2O was prepared and characterized by means of elemental analysis, IR, UV spectroscopy, 27 Al NMR , electrochemistry and X ray crystallography. The crystal of K 6H 3[ZnW 11 O 40 Al]·9 5H 2O is cubic, space group Fm 3m , with lattice constants a=b=c =2 144 8(2) nm, V =9 866(2) nm 3, Mo radiation, R =0 057 8 for 497 independent data with [ I>2δ(I) ]. The anion is of α type Keggin structure with C s symmetry.

Synthesis and Characterization of Charge-transfer Complexes of Aminoethylphosphono-and Dimethylaminoethylphosphono-heteropolytungstic Acids of Keggin Type Structure

Two charge-transfer complexes of 2a and 2b of Keggin type were synthesized and characterized by elemental analysis, IR spectra, UV spectra, XRD, TG-DSC; and were compared with Hquin-PW12. The primary structure of the heteropolyanions had not been changed after the formation of the charge transfer complexes.

Structures and Spectroscopy Properties of One Novel Keggin Type Polyoxomolybdate Compound

In this paper,One novel Keggin type polyoxomolybdate compounds have been hydrothermal synthesized:{[(CH3)2NH2]4(SiMo12O40)}[(CH3)2NH]·(DMF)0.5(1).The compound 1have been characterized by infrared spectrum,and the two-dimensional infrared correlation spectroscopy.

A Novel 3D Extended Network Cobalt Paradodecatungstate:Synthesis,Characterization and Crystal Structure of [Co(H_2O)_5]_2[Co(H_2O)_4]_3[H_2W_(12)O_(42)]·11H_2O

A cobalt paradodecatungstate [Co（H2O）5]2[Co（H2O）4]3[H2W12O42]·11H2O has been successfully synthesized and structurally characterized by X-ray crystallography. Structure analysis indicates that the title compound is of monoclinic, space group P21/n, with a = 13.449（3）, b = 19.585（4）, c = 13.990（3） °A, = 113.79（3）°, V = 3371.8（12） °A^3, Z = 2, R = 0.0519 and wR = 0.1242. The title compound exhibits a novel 3D extended network structure constructed by interconnecting the paradodecatungstate polyanion [H2W12O42]^10- clusters and cobalt^11 coordination ions.

Three Inorganic-organic Composite Polyoxotungstates:Syntheses,Characterization and Structures of [Cu(2,2ˊ-bpy)_2]_5[α-PW_(11.5)Cu_(0.5)O_(40)]·2H_2O,[Co(2,2ˊ-bpy)_2(N_3)_2]_4H_3[α-PW_(12)O_(40)]·3H_2O and [Cu(2,2ˊ-bpy)_2(4,4ˊ-bpy)]_2[α-GeW_(12)O_

Three new inorganic-organic composite polyoxotungstates [Cu（2,2＇-bpy）2]5[α-PW11.5Cu0.5O40]·2H2O 1, [Co（2,2＇-bpy）2（N3）2]4H3[α-PW12O40]·3H2O 2 and [Cu（2,2＇-bpy）2（4,4＇-bpy）]2[α-GeW12O40]-4H2O 3 （2,2＇-bpy = 2,2＇-bipyridine, 4,4＇-bpy = 4,4＇-bipyridine） have been hydrothermally synthesized and structurally characterized. 1 crystallizes in the orthorhombic space group Pna21 with a = 27.847（3）, b = 21.597（2）, c = 20.1179（19）A, V= 12099（2）A^3, Z= 4, GOF= 1.038, R = 0.0427 and wR = 0.1035; 2 belongs to the triclinic space group P1^- with a = 12.31150（10）, b = 16.1954（4）, c = 19.36290（10）A, α = 99.366（11）, β =105.168（8）, γ = 111.836（8）°, V = 3309.98（9）A3, Z = l, GOF = 1.024, R = 0.0739 and wR = 0.2216; and 3 crystallizes in the monoclinic space group P21/n with a = 12.858（4）, b = 20.943（6）, c = 15.598（5）A, β = 102.338（5）°, V= 4103（2）A3, Z = 2, GOF = 1.026, R = 0.0557 and wR = 0.1316. The common structural features of 1-3 are that their molecular structures all consist of a saturated a-Keggin polyoxoanion and several discrete metal-organic moieties. Intriguingly, 2 and 3 are composed of metal-organic coordination moieties with two mixed ligands.

Hydrothermal Synthesis and Structural Characterization of two Hybrid Keggin-based Polyoxometalates

Two new hybrid polyoxotungstates, [Co（2,2＇-bipy）3][a-H5PW11CoO40]-3H2O 1 and [Fe（2,2＇-bipy）3]2[a-HBW12O40]-2.5H2O 2 （2,2＇-bipy = 2,2＇-dipyridyl）, have been hydrothermally synthesized and characterized by IR, TGA and single-crystal X-ray structural analyses. The results of X-ray crystallography analyses exhibit that 1 consists of one a-Keggin anion [a-H5PW11CoO40]2- and one isolated [Co（2,2＇-bipy）3]2＋ complex, while 2 is constructed from one a-Keggin anion [a- HBW12O40]4- and two isolated [Fe（2,2＇-bipy）3]2＋ cations. The data for 1： orthorhombic system, space group Pbcn, a = 16.062（6）, b = 27.278（10）, c = 16.951（6）A, V = 7427（5）A3 and Z = 4; and those for 2： triclinic system, space group P1, a = 13.787（3）, b = 17.857（5）, c = 18.918（5）A, a = 88.009（12）, β = 72.768（10）, γ = 74.935（10）°, V = 4291（2）A3 and Z = 2.

Synthesis and crystal structure of an organic-inorganic complex [Cu(DMF)_3(H_2O)_2]_2[SiMo_(12)O_(40)]·2H_2O

The synthesis and crystal smacture of an polyoxometalate-based organic-inorganic complex [Cu（DMF）3（H2O）212[SiMo12O40].2H2O （DMF = N, N-dimethyl formamide） is described in this article. It was characterized using elemental analysis, thermal analysis, infrared, ultraviolet, and electron spin resonance spectroscopic studies. The X-ray crystallography analysis showed that the copper centers are pentacoordinated to show the square pyramidal geometry, and the polyanion [SiMo12O40]4- which is semi-coordinated to the copper（I/） centers prevents the existence of a sixth ligand. In addition, the intracationic hydrogen interaction enhanced the stability of the copper coordination cation.

Crystal Structure and Characterization of a Novel Neodymium Coordination Compound Based on Dawson Cluster

A new coordination compound, [{Nd(NMP)_2(H_2O)_6Cl}{Nd(NMP)_2(H_2O)_7}H (P_2Mo_(18)O_(62)) (NMP=N-methyl-2-pyrrolidone) was synthesized and characterized by elemental analyses, IR spectrum, and X-ray single crystal structural analysis. The crystal structure indicates that the title compound belongs to monoclinic space group C _c, with unit cell dimensions a =2.4528(5) nm, b =1.9495(4) nm, c =2.4405(5) nm, β =109.94(3)°, Z =4, V =10.970 (4) nm^3, D _c=2.262 g·cm^(-3), R 1=0.0676, wR 2=0.1441. The ESR spectrum of powder of the title compound at 110 K after being exposed to sunlight shows the signal of Mo^(5+), g =1.95. Cyclic voltammetry was measured in aqueous solution containing 0.1 mol·L^(-1) KCl as the supporting electrolyte and shows that the title compound undergoes two one-electron reversible reductions.

Synthesis and Crystal Structure of a Novel 1D Chain-like Organic Inorganic Hybrid Rare Earth Derivative of Polyoxometalate: H_(0.5)[Sm(H_2O)_6]_(0.25)[Sm(H_2O)_5]_(0.25){[Sm(H_2O)_7][Sm(H_2O)_2-(DMSO)][SiW_(11)O_(39)]}·4.5H_2O

A 1D chain-like organic-inorganic hybrid rare earth derivative of polyoxometalate H0.5[Sm（H2O）6]0.25[Sm（H2O）5]0.25{[Sm（H2O）7][Sm（H2O）2（DMSO）][SiW11O39]}·4.5H2O has been firstly synthesized by reaction of α-K8SiW11O39.13H2O, HClO4, Sm2O3 with dimethyl sulfoxide （DMSO） and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. The neighboring polyanionic units {[Sm（H2O）7][Sm（H2O）2（DMSO）][SiWHO39]}^2- are bridged together to a 1D chain structure by means of [Sm（H2O）2（DMSO）]^3＋ ion.

Synthesis and Crystal Structure of the Polyoxometalatebased Complex [Mn(DMSO)_5H_2O]_2SiMo_(12)O_(40)

A polyoxometalate-based complex [Mn(DMSO)5H2O]2SiMo12O40 has been synthe- sized and it crystallizes in triclinic, space group P with a = 11.863(2), b = 12.750(3), c = 13.255(3) , a = 83.62(3), b = 69.46(3), g = 87.14(3), V = 1865.6(6) 3, Dc = 2.445 g/cm3, Z = 1, ?= 2.660 mm-1, Mr = 2746.56, F(000) = 1328, R = 0.0569, wR = 0.1190 and GOF = 1.125. The results of X-ray crystal analysis and IR spectrum show that there exists strong interaction between the heteropolyanions [SiMo12O40]4- and coordination cations [Mn(DMSO)5H2O]2+ in solid state.

Hydrothermal Synthesis, Structure and Magnetic Property of a Novel Hexa-NiⅡ Substituted Polyoxometalate

A novel hexa-NiⅡ substituted trilacunary Keggin polyoxometalate [{Ni6（μ3- OH）3（en）3（H2O）6}（B-α-PW9O34）]-6H2O 1 （en = ethylenediamine） has been hydrothermally synthesized and characterized by IR spectra, elemental analysis, thermogravimetric analysis （TGA）, single-crystal X-ray diffraction and magnetic property. Compound 1 crystallizes in the hexagonal space R3c with a = 20.4124（5）, c = 21.4427（4）A, γ = 120.000°, V = 7737.5（3）A3, Z = 6, GOF = 1.083, R （wR） = 0.0317 （0.0610）. Single-crystal X-ray diffraction indicates that 1 contains a hexa-Nin substituted trivacant Keggin [{Ni6（μ3-OH）3（en）3（H2O）6}（B-α-PW9O34）] unit. The magnetic study shows the presence of ferromagnetic coupling interactions within hexa-Nin clusters with J1 = 0.69 cm-1 and J2 = 0.92 cm^-1 for 1.

STRUCTURE OF TRISUBSTITUTED TUNGSTOSILICATE ANION [A-β-SiW_9Al_3(H_2O)_2O_36(μ_3-O2/2)]_2~14-

Crystal of H14C[A-β-SiW9Al3(H2O)2O36(μ3-O2/2)]2 ·8H2O belongs to monoclinic system, space group P2/m. with a= 1 7. 525(6), b=14.348(3). c= 21. 669(8) A , β=113. 12(8)°, V = 5011 (3) A3,Z = 2. Dc = 3. 254 g. cm-3, A (MoKα) = 0. 70169 A , μ=223. 21 cm-1, F(000) = 4614, T = 298K. R=0. 066 for 3010 unique reflections [I≥5σ(I) ]. The crystal consists of water molecules, protons (or H3O+ ) and dimeric anions [A-β-SiW9Al3 (H2O)2O36(μ3-O2/2)D214.the half of which has a SiO1 tetrahedron in the center, a W3O13 group, two W2Al(H2O) O12 groups and a W2AlO13 group around the SiO4.

Synthesis,Spectroscopy and Antibacterial Activity of Supermolecular Compounds of Organotitanium Substituted Heteropolytungstates Containing 8-Quinolinol

Parent compounds of cyclopentadienyltitanium substituted heteropolytungstates with Keggin structure,An[(CpTi)XW11O39]·xH2O(A=Me4N,K;X=P,Si,Co;Cp=η5-C5H5) were synthesized in aqueous phase.By allowing parent heteropoly compounds to react with protonated 8-quinolinol,the title supermolecular compounds(C9H8NO)mAn[(CpTi)XW11O39]·xH2O(A=Me4N,H;X=P,Si,Co) were synthesized.The title compounds were characterized by means of elementary analysis,IR,UV,1H NMR,XRD and TG-DSC.The results indicate that the title compounds are new heteropoly compounds,and there is a charge transfer interaction between the organic cation and heteropoly anion.The results obtained from thermal analysis show that QCpTiPW,QCpTiSiW and QCpTiCoW begin to decompose at 212.4,194.2 and 171.2 ℃,respectively.The results obtained from antibacterial test reveal that QCpTiSiW has the best antibacterial activity,and the MIC values of QCpTiSiW against Escherichia coli and Staphylococcus aurous are 64.0 and 0.500 μg·mL-1,respectively.

Comparative study between gas phase and liquid phase for the production of DMC from methanol and CO_2

Direct synthesis of dimethyl carbonate （DMC） from methanol and carbon dioxide over Co1.5PW12O40 in liquid and in gas phase is investigated. The synthesized catalyst has been characterized by means of FTIR and XRD. Liquid phase experiment results showed that high pressures are favorable for the synthesis of DMC. However, DMC formation is limited by the reaction with co-produced water. DMC selectivity is more strongly dependent on the temperature than on the pressure of CO2. As for the reactions in gas phase, it has been found that both CH3OH conversion and DMC selectivity decreased with increasing temperature, owing to the decomposition of DMC at high temperatures. High temperatures and more amount of Co1.5PW12O40 catalyst favor the formation of dimethoxymethane （DMM） and methyl formate （MF）.

Synthesis and Conductivity of Undecatungstocobaltoruthenic Polyoxometallic Acid

Undecatungstocobaltoruthenic polyoxometallic acid H7[Ru（H2O）CoW11O39] 22H2O was synthesized by the stepwise acidification and the stepwise addition of solutions of the component elements as well as the ion ex changing-cooling method. The optimal proportion of the component compound and the pH of the synthesis reaction were given. The product was characterized by means of inductively coupled plasma（ICP）, IR, UV and thermal analy sis. The IR and UV results indicate that H7[Ru（H2O）CoW11O39] 22H2O possesses the Keggin structure. The results of AC impedance measurement show that its proton conductivity is 2.30×10-3 S/cm at room temperature（295 K） and a relative humidity of 75%.

Synthesis and proton conductibility of ternary germanic heteropoly acids

The ternary germanic heteropoly acids H_5GeW_(11)O_(40) centre dot 22H_2O andH_5GeMo_(11)VO_(40) centre dot 24H_2O were synthesized for the first time by the stepwiseacidification and the stepwise addition of solution of the component elements. The products werecharacterized by ICP, IR, UV, XRD and TG-DTA. The proton conductibility and the activation energy ofproton conduction of the heteropoly acids were investigated.