Synthesis and Spectroscopic Characterization of Organothiophosphoryl Polyoxotungstates α- [C6H11P (S) ]2Xn+W11O39(8-n)- (Xn+ = P5+, Si4+, Ge4+, Ga3+)

Organothiophosphoryl polyoxotungstate derivatives α-C6H11P(S)]2Xn W11O39(8-n)- (X=P, Si, Ge, Ga)were obtained by the reactions of the monovacant α-[Xn W11O39](12-n)- (X=P, Si, Ge, Ga) anions with electrophilic C6H11P(S)Cl2 in acetonitrile. These new organic-inorganic hybrid anions were characterized by elemental analyses, IR, 31P and 183W NMR spectrometries. The six-line 183W NMR spectrum indicates that [C6H11P (S) ]2Xn W11O39(8-n)- (X= P, Si, Ge, Ga) anions possess true Cs symmetry in acetonitrile. According to the spectroscopic observation and the chemical analyses, it is known that each of the hybrid anions consists of an α-[XW11O3)] framework on which two equivalent C6H11P(S) groups are grafted through P-O-W bridges.     

Extended structure constructed from sandwich-type tungstoantimonites fused together by water substitution on the sandwiching metal centers

A polyoxotungstate, {Na₆(H₂O)₁₆}[{Mn₃(H₂O)_6?W(OH)₂}{SbW₉O₃₃}₂]?·?13H₂O (1), has been synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction analysis. Compound 1 exhibits a 1-D chain-like structure composed of the sandwich-type tungstoantimonites fused together by water substitution on the sandwiching metal centers, rarely observed in POM chemistry. Electrocatalytic studies show that 1 has electrocatalytic activity for the reduction of nitrite.     

Fabrication of organic–inorganic nano-complexes using ABC type triblock copolymer and polyoxotungstates

New organic–inorganic nano-complexes were produced from a micelle of tri-block polymers; poly(styrene)-b-poly(2-vinylpyridine)- b-poly (ethylene oxide) (PS-PVP-PEO) and tungsten compounds such as tungstate (W₁²⁻), undecatungstophospate (PW₁₁⁷⁻) and undecatungstosilicate (SiW₁₁⁸⁻) in acidic aqueous solutions. The size and morphology of the complexes were characterized by measurements of dynamic light scattering, atomic force microscopy, and scanning electron microscopy. This complex is assembled mainly by the charge interaction between the inorganic polyanions and the positively charged PVP block in the PS-PVP-PEO molecule, which was confirmed by zeta-potential and fluorescence spectroscopic studies. In the absence of the inorganic anions, the zeta-potential of the micelle was +11 mV at pH 3 due to the positive charge of the PVP block. When the inorganic anion was mixed with the PS-PVP-PEO micelle, decrease in the zeta-potential due to charge neutralization occurred with incorporation of inorganic anions into the PS-PVP-PEO micelle. The minimum zeta-potential was 0, −33, and −35 mV for W₁²⁻ /PS-PVP-PEO, PW₁₁⁷⁻ /PS-PVP-PEO, and SiW₁₁⁸⁻ /PS-PVP-PEO complexes, respectively. Excess negative charge which occurred in the latter two complexes indicates that PS-PVP-PEO molecules bound PW₁₁⁷⁻ and SiW₁₁⁸⁻ by forces other than charge interaction. In addition, the incorporation of an inorganic polyanion into the micelle gave a new morphology to the micelle. In the absence of the polyanion, the PS-PVP-PEO micelles showed an extended conformation due to repulsive forces working among the positively charged PVP blocks. Addition of the polyanion caused the formation of shrunken forms of the micelles, since the charge repulsion was cancelled by the polyanion. This feature may be useful in developing a new type of functioning micelle.     

Syntheses,structures, and properties of two new hybrid Dawson-based polyoxotungstates [Mn(2,2′-bipy)3]H2 [Mn(2,2′-bipy)2][P2W18O62] and [Co(H2biim)3)]2H2[P2W18O62] · 8H2O

Two new hybrid Dawson-based polyoxotungstates, [Mn(2,2′-bipy)₃]H₂[Mn(2,2′-bipy)₂][P₂W₁₈O₆₂] (1) and [Co(H₂biim)₃)]₂H₂[P₂W₁₈O₆₂] · 8H₂O (2) (2,2′-bipy = 2,2′-bipyridine, H₂biim = 2,2′-biimdazole), have been prepared under hydrothermal conditions and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectra, thermogravimetric analyses (TGA), X-ray photoelectron spectroscopy (XPS), and photoluminescence spectra. Compound 1 is a 1-D zigzag chain constructed from alternate Dawson-type heteropolyanions [α-P₂W₁₈O₆₂]^6? and metal coordination cations [Mn(2,2′-bipy)₂]²⁺, in which the 1-D chains are extended into a 3-D framework through C–H ··· π and π–π stacking interactions. Compound 2 is a discrete structure consisting of [α-P₂W₁₈O₆₂]^6? and two [Co(H₂biim)₃)]²⁺ cations, forming a 3-D supramolecular framework via N–H ··· O hydrogen bonds and C–H ··· π interactions. Photoluminescence properties of 1 and 2 have been investigated at room temperature.     

Metal–oxo cluster-supported transition metal complexes: hydrothermal synthesis and characterization of [{Cu(phen)2}2SiW12O40]

A new neutral α-Keggin polyoxometalate, [{Cu(phen)₂}₂SiW₁₂O₄₀] (1) (phen?=?1,10-phenanthroline) was hydrothermally synthesized and characterized by IR, TG and single-crystal X-ray diffraction. The compound is monoclinic, space group P2₁/c with a?=?26.065(5), b?=?11.867(2), c?=?23.385(5)?Å, β?=?113.78(3)°, V?=?6619?ų, Z?=?4. X-ray analysis showed that both [Cu(phen)₂]²⁺ units are supported on the α-Keggin polyoxoanion [SiW₁₂O₄₀]^4? via the surface bridging and terminal oxygen atoms of two non-adjacent WO6 octahedra; these show unusual coordination environments. One Cu ion displays distorted trigonal bipyramidal geometry and the other square pyramidal. The unusual coexistence of complexes with different geometries is most likely caused by steric effects involving surface oxygen atoms of the heteropolytungstate and phen, which prevent the presence of a sixth coordinating atom. Weak π–π stacking interactions between phen groups give a 1D chain-like structure and hydrogen bonds are responsible for extended 2D and 3D motifs in the crystal.     

杂多酸环戊二烯钒衍生物的合成、谱学性质及抗肿瘤活性

合成了杂多酸环戊二烯钒衍生物[Bu₄N]₄[(CpV)PW₁₁O₃₉](1),[Bu₄N]₄H[(CpV)SiW₁₁O₃₉](2)和[Bu₄N]₄[A-β-(η5-CpV)SiW₉V₃O₄₀](3),并通过元素分析、IR、51V和183W NMR谱进行了结构表征。结果表明配合物(1)和(2)为结合型有机金属配合物,(3)为支撑型杂多酸有机金属配合物。体外抗肿瘤活性研究表明化合物(1)对HL-60和B₁₆均具有一定的抑制作用。     

Synthesis and Spectroscopic Characterization of Organothiophosphoryl Polyoxotungstates α-[C6H11P（S）]2X^n＋W11O39^（8-n）-（X^n＋—P^5＋，Si^4＋，Ge^4＋，Ga^3＋）

Organothiophosphoryl polyoxotungstate derivatives α-[C6H11P(S)]2X^n W11O39^(8-n)-(X=P，Si，Ge，Ga) were obtained by the reactions of the monovacant α-[C6H11P(S)] 2X^n W11O39^(8-n)-(X=P，Si，Ge，Ga) anions with electrophilic C6H11P(S)Cl2 in acetonitrile. These new organic-inorganic hybrid anions were characterized by elemental analyses, IR. ^31p and ^183W NMR spectrometries. The six-line ^183W NMR spectrum indicates that α-[C6H11P(S)] 2X^n W11O39^(8-n)-(X=P，Si，Ge，Ga) anions possess true Cs symmetry in acetonitrile. According to the spectroscopic observation and the chemical analyses, it is known that each of the hybrid anions consists of an α-[XW11O39] framework on which two equivalent C6H11P(S) groups are grafted through P-O-W bridges.     

Hybrid compounds of Keggin polyoxotungstate with transition metal ion as the central atom. Synthesis,structure and properties

The compounds (Hbipy)₂[Co(bipy)₂(H₂O)₄]₂(CoW₁₂O₄₀)·2bipy·7H₂O (1) and [Ni₂(Hbipy)₂(bipy)(H₂O)₄(H₂W₁₂O₄₀)]·5H₂O (2) (bipy = 4,4-bipyridine) were synthesized hydrothermally and characterized by elemental analysis, IR spectroscopy, TG analyses, solid ultraviolet diffuse spectroscopy and single crystal X-ray diffraction method. In 1 the complex ions, [Co(bipy)₂(H₂O)₄]²⁺, construct a supramolecular layer through π-π stacking interaction. The heteropolyanions with central Co atom and supramolecular layers are linked by hydrogen bonds. In 2 a 2D structure is formed from metatungstate anions and binuclear Ni-bipy complexes through the coordination of metatungstate anions and bipy to Ni ions. Between the layers and bipyridine molecules are the hydrogen bond interactions. The formation of 1 and 2 shows that the solution acidity and metal ions influence greatly the structure of the compounds. Solid ultraviolet diffusion results indicate that the compounds 1 and 2 are potential semiconductor materials. In 1 and 2 there exists a weak antiferromagnetic interaction.     

Synthesis and Characterization of Organophosphazene Polyoxotungstate [（N3P3）（SiW11O39H2）3]^12-

A new organophosphazene polyoxotungstate, [(N3P3)(SiW11O39H2)3]^12-, has been prepared by reaction of hexachlorocyclotriphosphazene with undecatungstosilicate, and characterized by elemental analysis, infrared spectroscopy, and multinuclear ^31p NMR.