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1.
Five chemical compounds, CuMoO4, Cu3Mo2O9, Cu2Mo3O10, Cu6Mo4O15, and Cu4?x Mo3O12 (0.10 ? x ? 0.40), were identified in the system Cu2OCuOMoO3 and characterized by DTA, X-ray powder patterns, ir spectra, and magnetic properties. Cupric molybdates CuMoO4 and Cu3Mo2O9 are stable in air up to 820 and 855°C, respectively, melting at these temperatures with simultaneous decomposition (oxygen loss). Congruent mp of cuprous molybdates Cu2Mo3O10 and Cu6Mo4O15, in argon, are 532 and 466°C, respectively. Nonstoichiometric phase Cu4?x Mo3O12 = Cu2+3Cu01?xMo6+3O12, melts in argon between 630 and 650°C depending on the value of x and at 525–530°C undergoes polymorphic transformation. Areas of coexistence of the above-mentioned phases are determined. The μeff of Cu2+ ions and θ values are: 1.80 B.M. and 28°K for CuMoO4, 1.71 B.M. and ? 12°K for Cu3Mo2O9, and 1.74 B.M. and ? 93°K for Cu4?xMo3O12. Below 200°K CuMoO4 becomes antiferromagnetic. Cu2Mo3O10 and Cu6Mo4O15 show weak temperature-independent paramagnetism.  相似文献   

2.
Synthesis and Crystal Structure of Cu6Mo5O18 Single crystals of the hitherto unknown compound Cu6Mo5O18 were prepared and investigated by X-ray methods (a = 18.884(19), b = 6.273(7), c = 15.259(23) Å, β = 130.40(5)°, space group C–C2/c, Z = 4). The typical features of the structure are described and compared with the crystal chemistry of oxocuprates(I). Observed and calculated powder patterns show that the correct composition of the earlier described compound Cu6Mo4O15 is Cu6Mo5O18.  相似文献   

3.
Coexistence Relations, Preparation and Properties of Ternary Compounds in the System Cu/Mo/O The phase diagram of the ternary system Cu/Mo/O is presented at 773 K. The compounds CuMoO4, Cu3Mo2O9, Cu4Mo5O17, Cu6Mo5O18, Cu4–xMo3O12, and CuxMoO3 are found to be thermodynamical stable. The homogeneity range of Cu4–xMo3O12 runs to x = 0.1–0.2. Single crystals of CuMoO4 and Cu3Mo2O9 were grown by chemical transport reactions with TeCl4, Cl2, HCl, and Br2 as transport agent. The results were compared with thermochemical calculations. The decomposition of CuMoO4 and Cu3Mo2O9 was investigated with thermal analysis and decompositon pressure measurements.  相似文献   

4.
A Contribution on CuPrMo2O8 and CuTbMo2O8 Single crystals of (I): CuPrMo2O8 and (II): CuTbMo2O8 were prepared by solid state reactions in closed copper tubes. They crystallize with orthorhombic symmetry, space group D-Pbca, (I): a = 10.4114, b = 9.8917, c = 14.8287 Å, (II): a = 10.2243, b = 9.7385, c = 14.6000, Z = 8. Both compounds are isotypic to CuYMo2O8, showing isolated MoO4 tetrahedra, square antiprismatic coordination of Ln3+ and Cu+ besides one edge of an O2? triangle. Calculations of the coulombterm of lattice energy support the oxidation state Cu2+ in combination with mixed valences of Mo6+ and Mo5+ on the molybdenum point positions.  相似文献   

5.
《Solid State Sciences》1999,1(4):189-198
The complex, K6[Mo2O5(cit)2]·5H2O was obtained by crystallization from reaction of [Et4N]3[Mo2FeS8O2 and potassium citrate (K3cit) in methanol and water under an atmosphere of pure nitrogen at ambient temperature. The complex is triclinic, space group P1, a = 11.843(8) Å, b = 13.717(8) Å, c = 10.287(5) Å, α = 108.11(4) °, β = 99.42(5) (1) °, γ = 66.52(4) °, R = 0.034 for 4510 observed (I > 3 σ (I)) reflections. Single crystal structure analysis reveals that citrate ligand coordinated to molybdenum atom through two carboxylato oxygens and one deprotonated hydroxyl oxygen together with one bridging oxygen atom and two terminal oxygen atoms completes distorted coordination octahedron around each molybdenum atom. IR spectra are in agreement with the structure.  相似文献   

6.
Synthesis, Properties, and Crystal Structure of Cu3Mo8O23X2 (X = Cl, Br, I) Single crystals of the Cu3Mo8O23X2 compounds were grown by chemical transport reactions at the lower temperature of a gradient 873–823 K without extra transport agent (auto transport). As DTA/TG measurements indicate, the gaseous compounds, necessary for chemical transport reactions, are formed by partial decomposition of Cu3Mo8O23X2 at 873 K. Cu3Mo8O23Br2 crystallizes with the orthorombic space group Pbcm (a = 4.021(1), b = 22.978(2), c = 21.673(2) Å, Z = 4). The crystal structure consists of pentagonal columns 1[Mo6O7O20/2] linked by additional MoO6/2 octahedra. All the polyhedra(pentagonal bipyramide, octahedra) are distorted. Infinite chains 1[Cu3Br2] along [100] are arranged in tunnels with s‐like square shape, left open by the pentagonal columns. Cu3Mo8O23Cl2 (a = 4.010(1), b = 22.942(2), c = 21.639(2) Å) and Cu3Mo8O23I2 (a = 4.052(1), b = 23.075(2), c = 21.719(2) Å) are isotypic.  相似文献   

7.
About Cu6La4Mo9O36 Single crystals of Cu6La4Mo9O36 were prepared and investigated by X-ray work. It shows trigonal symmetry, space group R3c — C; a = 20.892, c = 12.754 Å; Z = 6. Cu6La4Mo9O36 represents a new structure type, characterized by MoO4-tetrahedrons and three times capped trigonal prisms around La3+. Cu+ shows coordination numbers 2 + 1 or 2 + 2.  相似文献   

8.
A new coordination polymer based on octamolybdate anions and copper(II)‐mebpa complex fragments, namely, [{Cu(mebpa)}2β‐Mo8O26] ( 1 ), where mebpa is bis(2‐pyridylmethyl)methylamine, has been synthesized under the hydrothermal reaction and characterized by single‐crystal X‐ray diffraction, IR, thermogravimetric analysis and cyclic voltammetry. 1 is formed from β‐[Mo8O26]4? anions with {Cu(mebpa)}2+ fragments covalently attached via terminal oxygen atoms into a ribbon‐like chain. The β‐[Mo8O26]4? anions act as sexadentate ligands and the CuII ions adopt the common Jahn‐Teller distorted “4+2” coordination. Owing to the weak C‐H···O hydrogen bonding interactions, two crystallographically independent {CuN3O3} octahedra are located in the A and B layers respectively. The chemically modified carbon paste electrode (MCPE) displays well‐defined cyclic voltammograms with three two‐electron reversible redox couples in acidic aqueous solution and electrocatalytic activities toward the reduction of nitrite.  相似文献   

9.
A new organic–inorganic hybrid material constructed from octamolybdate anion and neutral dinuclear copper(I) units, H4{[Cu2(ophen)2]2[Mo8O26]}[Cu2(ophen)2] · H2O (1) (Hophen =2-hydroxy-1,10-phenanthroline), has been prepared under hydrothermal condition and characterized by elemental analysis, IR, XPS, TGA and single-crystal X-ray diffraction. Compound 1 crystallizes in the triclinic system, space group P 1, with a = 9.9091(8), b = 13.3981(8), c = 14.8266(10) Å, α = 84.6310(10), β = 83.0620(10)°, γ = 77.7800(10), V = 1905.0(2) Å3, Z = 1. Compound 1 contains a centrosymmetric polyoxoanion {[Cu2(ophen)2]2[Mo8O26]}4?, in which the β-[Mo8O26]4? is bisupported by two copper(I) coordination groups through the terminal oxygen atoms. The discrete molecules of 1 are extended into a 3-D supramolecular array through C–H ··· O hydrogen bonds and strong aromatic π–π stacking contacts.  相似文献   

10.
Two new isopolymolybdate-based metal–organic complexes, [Cu2(2-ptz)2(Mo4O14)0.5] (1) and [Cu3(OH)2(3-ptz)4(γ-H4Mo8O26)(H2O)4]·10H2O (2) (2-ptzH = 5-(2-pyridyl)-1H-tetrazole, 3-ptzH = 5-(3-pyridyl)-1H-tetrazole), constructed from isomeric ligands with different N-donor sites were synthesized under hydrothermal conditions. In 1, each [Mo4O14]4? cluster connected with six neighboring [Mo4O14]4? clusters through six binuclear [Cu2(2-ptz)2]2+ subunits to yield a 2-D layer. In 2, bidentate inorganic [Mo8O26]4? anions link the trinuclear [Cu3(OH)2(3-ptz)4] clusters to construct a 1-D chain. Adjacent chains connect through Mo–N bonds between the [Mo8O26]4? anions and pyridyl groups from the trinuclear clusters to form a 2-D layer. The effect of the N-donor sites of the rigid isomeric ligands on the structures of 1 and 2 was discussed. The electrochemical properties and photocatalytic activities of 1 and 2 have also been studied.  相似文献   

11.
Li6[TeMo6O24] · 18 H2O is triclinic (space group P1 , a = 1 041.7(1), b = 1 058.6(1), c = 1 070.8(1) pm, α = 61.08(1), β = 60.44(1), γ = 73.95(1)°). Single crystal X-ray structure analysis (Z = 1, 295 K, 317 parameters, 3 973 reflections, Rg = 0.0250) revealed an infinite branched chain of edge-sharing Li coordination polyhedra to be the prominent structural feature. One of the four crystallographically independent Li+ is coordinated octahedrally. The coordination polyhedra of the remaining Li+ are distorted trigonal bipyramids. Only three unique oxygen atoms (O(9), O(10), O(12)) of the centrosymmetric [TeMo6O24]6? anion are bound to Li+. The further positions in the coordination spheres of the Li+ are occupied by water molecules. Intermolecular hydrogen bonds involve mainly oxygen atoms of the [TeMo6O24]6? anion as nearly equivalent proton acceptors without regard to their different bonding modes to Te and Mo, respectively. Li6[TeMo6O24] · Te(OH)6 · 18 H2O crystallizes monoclinically in space group P21/n with Z = 4, a = 994.1(3), b = 2 344.8(10), c = 1 764.9(4) pm, and β = 91.36(4)°. Single crystal structure analysis with least squares refinement of 627 parameters (5 900 reflections, 295 K) converged to Rg = 0.0324. There are six unique Li+ cations. The coordination polyhedra of Li(1), Li(2), Li(3), and Li(4) are linked by common edges to yield an eight membered centrosymmetric strand. The coordination polyhedra of the remaining two Li+ sites (Li(5), Li(6)) are connected to a dimeric unit via a common corner. All oxygen atoms of the Te(OH)6 molecule are involved in the coordination of Li+. However, only three oxygen atoms (O(13), O(18), O(23)) of the [TeMo6O24]6? anion which lacks crystallographic symmetry are involved in the coordination of Li+. The oxygen atoms of the anion act as proton acceptors in hydrogen bonds of predominantly medium strength. Te(OH)6 molecules and [TeMo6O24]6? anions connected by strong hydrogen bonds form an infinite chain.  相似文献   

12.
On a New Copper Cobalt Borate Oxide with Isolated B2O5 Units: Cu2Co(B2O5)O Single crystals of a new compound with the empirical formula Cu2CoB2O6 were obtained by using a B2O3 flux technique. X-ray single crystal technique led to a new structure type. Cu2CoB2O6 crystallizes monoclinic, space group C-P21/c (No. 14); a = 3.2250(6); b = 14.847(1); c = 9.1171(6) Å; β = 93.67°; Z = 4. All metal sites are octahedrally coordinated and form a two dimensional framework consisting of edge sharing octahedra ribbons. In addition one observes isolated B2O5-units and oxygen which is not coordinated to boron. The far relation to the crystal structure of the mineral Warwickite is illustrated.  相似文献   

13.
By using cyclohexane‐1,2‐diamine (chxn), Ni(ClO4)2 ? 6H2O and Na3[Mo(CN)8] ? 4H2O, a 3D diamond‐like polymer {[NiII(chxn)2]2[MoIV(CN)8] ? 8H2O}n ( 1 ) was synthesised, whereas the reaction of chxn and Cu(ClO4)2 ? 6H2O with Na3[MV(CN)8] ? 4H2O (M=Mo, W) afforded two isomorphous graphite‐like complexes {[CuII(chxn)2]3[MoV(CN)8]2 ? 2H2O}n ( 2 ) and {[CuII(chxn)2]3[WV(CN)8]2 ? 2H2O}n ( 3 ). When the same synthetic procedure was employed, but replacing Na3[Mo(CN)8] ? 4H2O by (Bu3NH)3[Mo(CN)8] ? 4H2O (Bu3N=tributylamine), {[CuII(chxn)2MoIV(CN)8][CuII(chxn)2] ? 2H2O}n ( 4 ) was obtained. Single‐crystal X‐ray diffraction analyses showed that the framework of 4 is similar to 2 and 3 , except that a discrete [Cu(chxn)2]2+ moiety in 4 possesses large channels of parallel adjacent layers. The experimental results showed that in this system, the diamond‐ or graphite‐like framework was strongly influenced by the inducement of metal ions. The magnetic properties illustrate that the diamagnetic [MoIV(CN)8] bridges mediate very weak antiferromagnetic coupling between the NiII ions in 1 , but lead to the paramagnetic behaviour in 4 because [MoIV(CN)8] weakly coordinates to the CuII ions. The magnetic investigations of 2 and 3 indicate the presence of ferromagnetic coupling between the CuII and WV/MoV ions, and the more diffuse 5d orbitals lead to a stronger magnetic coupling interaction between the WV and CuII ions than between the MoV and CuII ions.  相似文献   

14.
The catalytic combustion of carbon black at 350–420°C in the presence of CuMoO4 has been investigated. The separate catalyst reduction and reoxidation stages make nonadditive contributions to the overall heat of the process. This indicates the formation of catalytically intermediate compounds during the redox reactions. The reduction of the catalyst with carbon yields the copper(I) molybdates Cu6Mo5O18 and Cu4Mo5O17 on its surface. The reoxidation of the reduced phases is accompanied by the release of Cu2O and MoO3 followed by the formation of the active phase Cu4 ? x Mo3O12, which is capable of activating carbon black combustion.  相似文献   

15.
Synthesis, Crystal Structure, and Properties of Copper(II) Ultraphosphate CuP4O11 CuP4O11 was synthesised from Cu2P4O12 and P4O10 (500°C, sealed silica ampoules) using iodine and a few mg of CuP2 or phosphorus as mineraliser. Chemical transport reactions in a temperature gradient 600 → 500°C led to the formation of well developed, colourless, transparent crystals with edge-lengths up to 5 mm (deposition rate m ≈? 2 mg/h). The crystal structure of copper(II) ultraphosphate (C1 ; Z = 8; a = 13.084(3) Å, b = 13.024(2) Å, c = 10.533(2) Å, α = 89.28(2)°, β = 118.42(2)°, γ = 90.30(2)°) has been determined and refined from X-ray data obtained from a pseudo-merohedrally twinned crystal (twin element two-fold rotation axis // b; volume ratio: 17/3; 3063 independent reflections with 2θ ? 53.4°; 291 variables; conventional residual (based on F) R1 = 0.038, wR2 = 0.101 (based on F2), GooF = 1.10). The crystal structure of CuP4O11 is built from four crystallographically independent ten-membered polyphosphate rings of very similar conformation. These rings are linked to form two-dimensional nets parallel (?2 0 1) planes. There is a close topological relationship between these nets and those formed in polyphosphides CdP4 and CuP2. Copper on two crystallographic sites (Cu2P8O22) is coordinated by oxygen thus forming elongated [CuO6] octahedra (deq(Cu? O) ≈? 1.96 Å; dax(Cu? O) ≈? 2.34 Å). The crystal g-tensor of CuP4O11 has been determined from powder samples to g1 = 2.09, g2 = 2.24, g3 = 2.36. These values are in good agreement with molecular g-values from calculations within the framework of the angular overlap model on the two independent CuO6 octahedra (Cu2+(1): gx = 2.09, gy = 2.10, gz = 2.52; Cu2+(2): gx = 2.08, gy = 2.11, gz = 2.52) assuming exchange coupling. The observed broad absorption band (7000 cm?1 to 13000 cm?1) from powder reflectance measurements (4000–28000 cm?1) and the bulk magnetic susceptibility of μexp = 1.99 μB is also reproduced nicely by this calculations.  相似文献   

16.
Three new 2D/3D supramolecular architectures derived from Cu‐organic subunits and Keggin anions, [CuII2(biz)8(HPMoVI10MoV2O40)(H2O)2] · 2H2O ( 1 ), [CuI4(biz)8(SiW12O40)] · 2H2O ( 2 ) and [CuI2(dmbiz)4(Hdmbiz)2(SiW12O40)] ( 3 ) (biz = benzimidazole, dmbiz = 5, 6‐dimethyl benzimidazole), were obtained under hydrothermal conditions. Single crystal X‐ray diffraction analysis reveals that compound 1 has two kinds of [CuII(biz)2]2+ cations, which are further extended by Keggin anions into a 2D (4, 8)‐connected supramolecular network by hydrogen bonding interactions. In compound 2 , four types of [CuI(biz)2]+ subunits link the [SiW12O40]4– anions to form a 3D (2, 6)‐connected supramolecular structure. Compound 3 shows a 3D supramolecular network with a NaCl‐type topology constructed by [CuI(dmbiz)2]+ subunits, anions, and discrete [Hdmbiz]+ cations. Moreover, the electrochemical and photocatalytic properties of compounds 1 and 2 were investigated.  相似文献   

17.
The first Alkaline Alkaline-Earth Oxocuprate (II, III): NaBa2Cu22+Cu3+O6 The compound NaBa2Cu3O6 was prepared by heating of Na2O2, BaO2, Cu2O in closed Ag-tubes. X-ray single crystal investigations led to orthorhombic symmetry, space group D-Fmmm; a = 8.4229; b = 11.4418; c = 14.4063 Å; Z = 8. Cu2+ and Cu3+ show square planar polygones of four and Na+ trigonal prisms of six O2?. The two barium point positions show coordination numbers C.N. = 8 and 6 + 4. The crystal structure is discussed.  相似文献   

18.
Two new reduced molybdenum pyrophosphates, Na28[Na2{(Mo2O4)10(P2O7)10(HCOO)10}]·108H2O ( 1 ) and Na22(H3O)2[Na4{(Mo2O4)10(P2O7)10(CH3COO)8(H2O)4}]·91H2O ( 2 ) have been synthesized and characterized by single‐crystal X‐ray diffraction. Red crystals of 1 are triclinic, space group , with a = 17.946(4) Å, b = 18.118(4) Å, c = 21.579(4) Å, α = 114.47(3)°, β = 93.54(3)°, γ = 114.39(3)° and V = 5581.8(19) Å3, and orange crystals of 2 are monoclinic, space group P21/n, with a = 21.467(4) Å, b = 23.146(5) Å, c = 24.069(5) Å, β = 101.76(3)° and V = 11708(4) Å3. They are both constructed by MoV dimers ({Mo2O4(OP)4(HCOO)} in 1 , {Mo2O4(OP)4(CH3COO)} and {Mo2O4(OP)4(H2O)2} in 2 ) and pyrophosphoric groups. Their structures can be described as two interconnected nonequivalent wheels which are approximately perpendicular, delimiting a large cavity. The larger wheel contains six MoV dimers, while the smaller one has four dimers.  相似文献   

19.
Single crystals of novel Strandberg type molybdophosphonate complex, (C5H7N2)6[Cu(H2O)3HP2Mo5O23]2·4H2O, are synthesized in aqueous solution and characterized by X-ray diffraction, spectroscopy (diffuse reflectance, UV–Vis and IR) and thermal analysis. Single crystal X-ray diffraction analysis reveals that this novel compound is composed of [Cu(H2O)3HP2Mo5O23]3? anions, three distinct 2-aminopyridinium cations as counter-ions and two distinct crystallization water molecules. The crystal packing is stabilized by H-bonds and π–π interactions, resulting in a 3D framework. In addition, the magnetic behavior of the related compound is measured. Magnetic measurements from 100 to 2 K indicate the presence of an antiferromagnetic coupling between the Cu (II) ions in (C5H7N2)6[Cu(H2O)3HP2Mo5O23]2·4H2O complex, resulting in a maximum of an antiferromagnetic–paramagnetic transition at TN = 7 K. Magnetic susceptibility data indicate an antiferromagnetic Curie–Weiss behavior in the studied temperature range, and molecular field theory gives the (J/kB) values of the nearest neighbor interactions between copper ions.  相似文献   

20.
On the Crystal Structure of Cu3NbTaO8 Single crystals of Cu3NbTaO8 were prepared by solid state reaction. X-ray investigations led to triclinic symmetry, space group C? P1 with a = 5.179; b = 5.474; c = 6.003 Å; α = 72.85°; β = 83.39°; γ = 65.77°; Z = 1. Nb5+ and Ta5+ occupy one point position statistically. Both ions show an octahedral oxygen surrounding. Cu(1) is inside an elongated CuO6 octahedra and Cu(2) is coordinated by 5 O2? forming a distorted square pyramid. The polyhedra connection is shown and discussed.  相似文献   

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