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1.
Liu  Jie  Mei  Wen-Jie  Xu  An-Wu  Tan  Cai-Ping  Ji  Liang-Nian 《Transition Metal Chemistry》2003,28(5):500-505
A series of novel heteropoly blues, Ln2H2[SiMo11Ni(H2O)O39] · nH2O (Ln = La, Ce, Pr, Nd, Sm, or Gd), had been prepared and characterized by elemental analysis, i.r., u.v., c.v., t.g.–d.t.a., XPS, 29Si-n.m.r., electrochemistry and magnetic susceptibility. Compared with non-reduced heteropolyoxometallates, the heteropoly blue anion in Ln2H2[SiMo11Ni(H2O)O39] · nH2O still retains the -Keggin structure but with a slight distortion, with Ni and Mo atoms distributed statistically in the crystal. The antiviral activities of these complexes have been studied using tomato mosaic virus. Ln2H2[SiMo11Ni(H2O)O39] · nH2O show excellent antivirus activities, and the cure rate reaches to 80–90%.  相似文献   

2.
Five mixed‐metal mixed‐valence Mo/V polyoxoanions, templated by the pyramidal SeO32? heteroanion have been isolated: K10[MoVI12VV10O58(SeO3)8]?18 H2O ( 1 ), K7[MoVI11VV5VIV2O52(SeO3)]?31 H2O ( 2 ), (NH4)7K3[MoVI11VV5VIV2O52(SeO3)(MoV6VV‐ O22)]?40 H2O ( 3 ), (NH4)19K3[MoVI20VV12VIV4O99(SeO3)10]?36 H2O ( 4 ) and [Na3(H2O)5{Mo18?xVxO52(SeO3)} {Mo9?yVyO24(SeO3)4}] ( 5 ). All five compounds were characterised by single‐crystal X‐ray structure analysis, TGA, UV/Vis and FT‐IR spectroscopy, redox titrations, and elemental and flame atomic absorption spectroscopy (FAAS) analysis. X‐ray studies revealed two novel coordination modes for the selenite anion in compounds 1 and 4 showing η,μ and μ,μ coordination motifs. Compounds 1 and 2 were characterised in solution by using high‐resolution ESI‐MS. The ESI‐MS spectra of these compounds revealed characteristic patterns showing distribution envelopes corresponding to 2? and 3? anionic charge states. Also, the isolation of these compounds shows that it may be possible to direct the self‐assembly process of the mixed‐metal systems by controlling the interplay between the cation “shrink‐wrapping” effect, the non‐conventional geometry of the selenite anion and fine adjustment of the experimental variables. Also a detailed IR spectroscopic analysis unveiled a simple way to identify the type of coordination mode of the selenite anions present in POM‐based architectures.  相似文献   

3.
Three new supramolecular compounds based on triethylenediamine and different polyoxometalates [WVI3VV3O19H]{[Cu(HDABCO)]2(H2O)} (1), [P2MoVI18O62][HDABCO]2[H2DABCO]2·12 H2O (2) and [MoVI7.5WVI0.5O27][Cu(HDABCO)]2·2 H3O·2 H2O (3) (DABCO=triethylenediamine) have been synthesized hydrothermally and characterized by IR, TG, XPS and X-ray diffraction analyses. Crystal structure analyses reveal that compound 1 exhibits a face-centered cubic packing motif, compound 2 displays a supramolecular structure constructed form the “chains” arranged hexagonally, compound 3 contains [Mo7.5W0.5O27] chain decorated by [Cu(HDABCO)]2+ cations, which was then packed into a layer structure. These results show that the same organonitrogen combining with the different POMs will yield different supramolecular networks.  相似文献   

4.
Summary A binuclear oxo MoV hypophosphite of composition [Mo2O4(H2PO2)2(H2O)2], is prepared by direct reduction of MoVI oxide hydrate (MoO3·H2O) with hypophosphorus acid in an argon atmosphere, and characterised by i.r., and electronic spectra, magnetic susceptibility and cyclic voltammetry measurements.1H and31Pn.m.r., x-ray diffraction and thermal analysis data contribute to its molecular structure elucidation, and a dioxobridged dioxo MoV with bidentate hypophosphite ion and water molecule completing the octahedral coordination around each Mo atom is proposed.  相似文献   

5.
A family of solution-stable polyanions [Na⊂{LnIII(H2O)}{WVIO(H2O)}PV4WVI26O98]12− (Ln=Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y) represent the first examples of polyoxometalates comprising a single lanthanide(III) or yttrium(III) ion in a rare trigonal prismatic O6 environment. Their synthesis exploits the reactivity of the organophosphonate-functionalized precursor [P4W24O92(C6H5PVO)2]16− with heterometal ions and yields hydrated potassium or mixed lithium/potassium salts of composition KxLnyH12–xy[Na⊂{Ln(H2O)}{WO(H2O)}P4W26O98]⋅nH2O⋅mLiCl (x=8.5–11; y=0–2; n=24–34; m=0–1.5). The Dy, Ho, Er and Yb derivatives are characterized by slow magnetization relaxation.  相似文献   

6.
Molybdenum polyoxometallates with the buckyball structure, ((NH4)42[Mo72VIMo60VO372(H3CCOO)30(H2O)72] · 30H3CCOONH4 · 250H2O (I), (NH4)42[Mo72VIMo60VO372(ClCH2COO)30(H2O)72)] · 250H2O · 15ClCH2COONa (II), in particular, as parts of polymer-containing compositions were studied by EPR, NMR, IR, and Raman spectroscopy. The structural and chemical aspects responsible for the formation of the observed spectra were considered.  相似文献   

7.
A new organic–inorganic hybrid (H2en)2[[Cu(en)2]AsIIIAsVMoVI9O34]·6H2O (1), containing a 1-D helical chain based on the trivacant monocapped Keggin arsenomolybdate and the copper complex linker {[Cu(en)2][AsIIIAsVMoVI9O34]}n4n? (en = ethylenediamine), has been synthesized and characterized by IR spectra, TG analyses, single-crystal X-ray diffraction, and high-resolution electrospray ionization mass spectrometry (ESI-MS). Large voids are observed and a 1-D chain containing repeated (H2O)8 water units from lattice water molecules is formed along the a axis in the crystal structure. The high-resolution ESI-MS shows that the intact framework [Cu(en)2][AsIIIAsVMoVI9O34]4? exists in solution.  相似文献   

8.
The hydrothermal reaction of MoO3, V, Na2WO4· 2H2O, [N(CH2CH2)3N](1,4-diazabicyclo[2.2.2] octane), and H2O at 160°C for 90h gave dark-brown crystals of [HN(CH2CH2)3N]2[HMoVMoVI 5O19]·[N(CH2CH2)3N], (1), in 40% yield. Complex (1) is the first one-electron reduced mixed-valence hexamolybdate to be crystallized and structurally characterized. The crystal structure of (1) consists of discrete [HMoVMoVI 5O19]2– anions, [HN-(CH2CH2)3N]+ cations, and neutral [N(CH2CH2)3N] molecules of crystallization.  相似文献   

9.
Two polyoxometalate-based inorganic metal-organic hybrid supramolecular complexes [Cu(2,2′-bpy)2]2[VIV 2MoV 5MoVI 7O38(PO4)] (1) (2,2′-bpy?=?2,2′-bipyridine) and [Cu(2,2′-bpy)2]2[MoVMoVI 11O36(PO4)]?·?3H2O (2), have been hydrothermally prepared and structurally characterized by single-crystal X-ray diffraction. Both complexes are constructed from polyoxoanions (the bivanadyl capped α-Keggin polymolybdate anion [VIV 2MoV 5MoVI 7O38(PO4)]4? for 1 and the reduced 12-molybdophosphate anion [MoVMoVI 11O36(PO4)]4? for 2) and copper(II) complex cations [Cu(2,2′-bpy)2]2+, forming two-dimensional (2D) layer network structures, in which the polyoxoanion and the complex fragment cation connect with each other through Cu?···?Opolyoxoanion short contact weak interactions, which mediate ferromagnetic interaction.  相似文献   

10.
Two Keggin-type phosphododecamolybdate compounds [Cd(2,2′-bpy)3]2[PMoVMoVI 11O40] (1) and [H3PMo12O40]·3(4,4′-bpy)·4H2O (2) (bpy=bipyridine) were prepared by the hydrothermal method for the first time and characterized by elemental analyses, X-ray single-crystal diffraction, ESR spectra, and IR spectra, showing that compound 1 consists of a mixed valence Keggin polyanion [PMoVMoVI 11O40]4− and two isolated coordinated cations [Cd(2,2′-bpy)3]2+, while compound 2 is an intermolecular compound based on organic substrate 4,4′-bpy and heteropoly acid unit H3PMo12O40. Furthermore, both the compounds show strong photoluminescence properties in the solid state at room temperature. The catalytic activities of the two compounds were also determined by the oxidation of benzaldehyde to benzoic acid using H2O2 as oxidant in a liquid–solid triphase system.  相似文献   

11.
Two new neutral Keggin-polyoxometalate derivatives: [{Co(2,2′-bipy)2(H2O)}2]–[PMoVI7MoV5O40(VIVO)2] (1) and [{Ni(phen)2(H2O)}2](H3O) [PMoVI10MoV2O40] · 4H2O (2) have been synthesized under hydrothermal conditions and characterized by i.r., t.g. analysis, x.p.s. spectra and single-crystal X-ray diffraction. In the case of (1), the polyoxoanion cluster [PMo12O40]8− is capped by two vanadium atoms via four bridging oxo groups on two opposite {Mo4O4} pits of the Keggin polyoxoanion. Two {Co (2,2′-bipy)2(H2O)} fragments are supported on the two vanadium atoms through two terminal oxygen atoms from two vanadium atoms. In (2), two {Ni(phen)2(H2O)}2+ moieties are linked to the molybdophosphate cluster [PMo12O40] core to form a neutral bimetallic cluster. Furthermore, through the linkages of ππ stacking interactions and hydrogen bond contacts, extended three-dimensional supramolecular networks in the solid of (1) and (2) were formed.  相似文献   

12.
Xu  Mei-Xian  Lin  Shen  Xu  Li-Min  Zhen  Si-Lin 《Transition Metal Chemistry》2004,29(3):332-335
The title compound H3[PMo12O40]· 3C2H6O was prepared and characterized by X-ray crystallography, its i.r. spectrum, cyclic voltammetry and e.s.r. spectra. The anion of the title compound is a Keggin-type heteropoly structure based upon a central PO4 tetrahedron surrounded by 12 MoO6 octahedra arranged in four groups of three edge-shared octahedra Mo3O13. Weak hydrogen bonds exist between the organic solvent molecules and the heteropoly anion. The catalytic activity of the title compound was determined by the synthesis of butyl acetate. The conversion of n-BuOH reached 93.3% and the yield of MeCO2Bu-n was 92.0% when the ratio of MeCO2H to n-BuOH, catalyst amount, reaction time, reaction temperature were 2:1, 0.24% of the reactants (50 mg), 2.0 h and 115 120 °C, respectively.  相似文献   

13.
The reactions of LnCl3·6H2O (Ln=Eu or Dy) and Na2[Mo2O3S(HNTA)2]·6H2O afford Na[Mo2O3S(HNTA)2]2·Eu(H2O)9·3H2O (1) (NTA=nitrilotriacetate) and Na{(H2O)6Dy[Mo2O3S(HNTA)2]2}·7.5H2O (2), respectively. The [Mo2O3S(HNTA)2]2− cluster units of 1 are interconnected by Na+ into a 3-D open framework with rutile topology templated by . The coordination of [Mo2O3S(HNTA)2]2− to the slightly smaller Dy3+ ion of greater ionic potential as a consequence of lanthanide contraction has been observed to form the pentanuclear heterometallic {Dy(H2O)6[Mo2O3S(HNTA)2]2}, which is linked by Na+ and hydrogen bonds between the protonated carboxylate groups into a 3-D supramolecular framework. The weak antiferromagnetic interactions between the Dy3+ ions of 2 have been observed.  相似文献   

14.
Two new organic–inorganic hybrid compounds, [Cu(phen)(prz)]2[PMoV1MoVI7VIV2VV4O42]·4H2O (1) and [Ag2(phen)4]2[PMoV1MoVI7VIV2VV4O42] (2) (phen = 1,10-phenanthroline, prz = pyrazine), have been synthesized and characterized by IR, XPS, XRD, UV–vis, fluorescent spectra analyses, elemental analyses, X-ray diffraction analyses, TG analyses, and cyclic voltammetric measurements. Both compounds are formed by Keggin POM cores and transition metal fragments. Compound 1 exhibits an unprecedented 1-D chain structure constructed from [PMoV1MoVI7VIV2VV4O42]4? and [Cu(phen)(prz)]2+ in the –A–B↑–C–B↓– linking mode. Compound 2 shows a supramolecular structure formed by [PMoV1MoVI7VIV2VV4O42]4? and [Ag2(phen)4]2+.  相似文献   

15.
On the Thermal Behaviour of Heteropoly Acids of the Type H3+n[PVnMo12?nO40] · x H2O (n = 0, 1, 2, 3). II. Raman and Infrared Spectroscopic Investigations The investigation of de- and rehydratization of the heteropoly acids H3+n[PVnMo12?nO40] · x H2O (n = 0, 1, 2, 3) shows typical changes in the region of valence and bridging vibrations in the Raman and infrared spectra, in particular during the existence of ?anhydrous”? forms. The time dependence of rehydratization is also demonstrated well with a special Raman sample technique.  相似文献   

16.
The photolysis of MoCl4(MeCN)2 in MeCN in the presence of small amounts of H2O proceeds according to the equation MoIVCl4·H2OMoVIOCl4 + H2. It is suggested that a ligand field excited state of MoCl4(H2O) n , which is initially populated by light absorption, is deactivated to a reactive metal-to-ligand (MoIVH2O) charge transfer state.  相似文献   

17.
Heteropolyblueisthereducedproductofthepoly oxometalates.Ithasattractedmuchattentionbecauseofitsnovelstructure ,uniquepropertiesandpotentialap plicationsinthefieldsofcatalysis ,pharmaceuticalchemistryandfunctionalmaterials .1 3 Atearlystage ,heteropolybluewa…  相似文献   

18.
An inorganic–organic hybrid compound, (H2bpy)3[AsIIIAs2 VMo15 VIMo3 VO62]·3H2O (bpy: 4,4′-bipyridine) (1) has been synthesized under hydrothermal conditions and characterized by elemental analysis, X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction, IR spectrum, UV–Vis spectrum, thermogravimetric analysis and single-crystal X-ray diffraction. The crystallographic analysis reveals that compound 1 is composed of a Wells–Dawson polyoxoanion [As2 VMo15 VIMo3 VO62]9? with the mixed valence of MoV,VI, which acts as a tetradentate ligand coordinating with the AsIII cation to form the mixed valence AsIII,V containing arsenomolybdate with the single cap structure in a chelate coordination mode. In the solid state, compound 1 shows a 3D supramolecular structure through hydrogen-bonding interactions (C–H···O, N–H···O, N–H···N). In addition, compound 1 exhibits reversible multi-electron redox processes and effective electrocatalytic activities towards the reduction of H2O2, NaNO2 and KBrO3. Moreover, compound 1 is used as a reducing agent of the graphene oxide to prepare graphene by a green chemistry type one-step synthesis method, which is characterized by XPS, Raman spectroscopy, PXRD, IR, scanning electron microscopy and transmission electron microscopy.  相似文献   

19.
本实验采用分步加原料的方法,以不同的磷钼钒比,直接合成了三种1:12系列的钼钒磷杂多酸铵蓝,即(NH4)4H2·15H2O(bluc—1),(NH4)5H2·和(NH4)6H2·30H2O(bluc-3),并研究了反应条件对这些钼钒磷杂多酸铵蓝形成的影响.通过元素分析、电位滴定、电子光谱和X射线衍射等测试手段研究了配合物的性质,并确定了配合物的组成.  相似文献   

20.
The crystal structure of the mixed-valence Np(V) and Np(VI) compound Na6[(NpVO2)2(NpVIO2)(MoO4)5] · 13H2O was determined. The structure is built of the anionic layers [(NpVO2)2(NpVIO2)(MoO4)5] 6n- n with the Na+ cations and crystal water molecules between them. The Np(V) and Np(VI) atoms in the anionic layers are ordered. The motif of the anionic layer is close to that found in Mg2[(UO2)3(SeO4)5] · 16H2O. The isostructural mixed-valence Np(V) and U(VI) compound was also synthesized.  相似文献   

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