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1.
2.
Single crystals of the title compound are obtained from a melt of U3O8, MoO3, and excess Cs2CO3 (Pt crucible, 950 °C, 12 h, cooling rate 5 °C/h).  相似文献   

3.
New Alkali Cyclosilicates: Cs5AgSi3O9 and Cs6Na6Si6O18 The new cyclosilicates were obtained from reactions of the binary oxides at 450–500 °C under inert gas atmosphere. Cs5AgSi3O9 crystallizes in the space group P21/m with the lattice constants a = 968,2(2) pm, b = 652,7(1) pm, c = 1162,6(3) pm, β = 93,84(2)° and Cs6Na6Si6O18 in R‐3m with a = 1208,0(1) pm, c = 1458,9(2) pm (IPDS data sets). The characteristic features are isolated rings, [Si3O9]6– and [Si6O18]12–, respectively. In Cs5AgSi3O9 these are connected via Ag+ to chains. Layers of [NaO4]‐tetrahedra separate the hexameric rings in Cs6Na6Si6O18. Coordination numbers of caesium are observed between C.N. 3 and C.N. 9 in these alkali rich cyclosilicates. MAPLE calculations of both cyclosilicates as well as the absorption and IR spectrum of Cs5AgSi3O9 are presented. Preparative and thermoanalytical techniques have been used to investigate the reactivity of Cs5AgSi3O9 in the presence of cobalt and nickel metal.  相似文献   

4.
New Oxogallates of Alkaline Metals: On K6[Ga2O6] and Rb6[Ga2O6] as well as Na3GaO3 and Cs6[Ga2O6] Due to powder and single crystal data K6[Ga2O6] a = 7.099; b = 11.116; c = 6.484 Å; ß = 101.66° and Rb6[Ga2O6] a = 7.393; b = 11.475; c = 6.798 Å; ß = 103.5° crystallize isotypic with K6[Fe2O6]; space group C2/m-C32h; As well has been prepared the hitherto unknown Na3GaO3 a = 11.48, b = 10.82, c = 6.13 Å, space-group Imcm or I2cm Z = 8; and Cs6[Ga2O6] a = 7.26, b = 12.1, c = 7.68 Å, ß = 105°, Z = 4, space-group P21/a.  相似文献   

5.
Newly prepared are the cubic derivatives of the perovskite type of structure: K2NaInF6 (a = 8.560 Å), K2NaTlF6 (8.668), K2NaScF6 (8.482), K2NaYF6 (8.711), Cs2NaInF6 (8.905), Cs2NaTiF6 (8.995), Cs2NaScF6 (8.853), all colourless, as well as K2NaCuF6 (8.203 Å, green) and Cs2KMnF6 (tetragonal, a = 8.933; c = 9.265 Å, violett). K2NaCuF6 [μ = 2.87 μB, θ = ?17°] and Cs2KMnF6 [;μ = 4.88 μB, θ = ?5°] obey the Curie-Weiss law. The volume chemistry of the compounds is discussed in detail.  相似文献   

6.
K_6CrNb_(15)O_(42)crystallizes in the hexagonal system with a=9.126(3)A,c=12.068(3)A,V=870.4(5)A~3,and space group P6_2/mcm,Z=1.The structure was solved using direct method andFourier Techniques.Of the 829 unique reflections measured by counter techniques,448 with I≥3σ(I)were used in the least-squares refinement of the model to R=0.034(R_w=0.044).The structureof KoCrNb_(15)O_(42)may be described as consisting of corner-shared and edge-shared octahedra,the ringunits composed of six octahedra of Nb(1)are corner-shared one another along the c-axis to formhexagonal column octahedra chains which are connected by K~+ and octahedra of Nb(2).  相似文献   

7.
The depression of freezing point of molten K2Cr2O7 and KNO3 as solvents was measured after addition of small concentrations of the following compounds: to K2Cr2O7: MoO3, CrO3, (NH4)2CrO4, K2MoO4, Na2MoO4, Li2MoO4, and Na2Mo2O7, respectively; to KNO3: CrO3, (NH4)2Cr2O7 K2Cr2O7, K2CrO4 and MoO3, (NH4)6(Mo7O24) · 4 H2O, K2Mo2O7, K2MoO4, Na2MoO4 and Li2MoO4, respectively. It could be concluded from the measured values of the freezing point depression if a reaction between solvent and solute took place.  相似文献   

8.
The structure of K4MnMo4O15 was solved from single-crystal X-ray diffraction data (a = 10372, c = 8.160 Å, Z = 2, space group P-3, 2152 reflections, R = 0.039). The structure is of new, glaserite-like, type. A characteristic and original feature of the structure is a Mn(II)O6 octahedron with six MoO4 tetrahedra attached to it by their vertices; the octahedron is linked with a MoO6 octahedron by a common face. The MoO4 tetrahedra bridge the octahedral dimers with each other, forming lacy layers with potassium atoms lying between the layers. K4M2+Mo4O15 (M2+= Mg, Co, Cd) phases, which have similar structures, have been synthesized and characterized.  相似文献   

9.
Two new compounds, namely cubic tricaesium lithium dizinc tetrakis(tetraoxotungstate), Cs3LiZn2(WO4)4, and tetragonal trirubidium dilithium gallium tetrakis(tetraoxomolybdate), Rb3Li2Ga(MoO4)4, belong to the structural family of Cs6Zn5(MoO4)8 (space group I 3d , Z = 4), with a partially incomplete (Zn5/61/6) position. In Cs3LiZn2(WO4)4, this position is fully statistically occupied by (Zn2/3Li1/3), and in Rb3Li2Ga(MoO4)4, the 2Li + Ga atoms are completely ordered in two distinct sites of the space group I 2d (Z = 4). In the same way, the crystallographically equivalent A + cations (A = Cs, Rb) in Cs6Zn5(MoO4)8, Cs3LiZn2(WO4)4 and isostructural A 3LiZn2(MoO4)4 and Cs3LiCo2(MoO4)4 are divided into two sites in Rb3Li2Ga(MoO4)4, as in other isostructural A 3Li2R (MoO4)4 compounds (AR = TlAl, RbAl, CsAl, CsGa, CsFe). In the title structures, the WO4 and (Zn,Li)O4 or LiO4, GaO4 and MoO4 tetrahedra share corners to form open three‐dimensional frameworks with the caesium or rubidium ions occupying cuboctahedral cavities. The tetrahedral frameworks are related to that of mayenite 12CaO·7Al2O3 and isotypic compounds. Comparison of isostructural Cs3M Zn2(MoO4)4 (M = Li, Na, Ag) and Cs6Zn5(MoO4)8 shows a decrease of the cubic lattice parameter and an increase in thermal stability with the filling of the vacancies by Li+ in the Zn position of the Cs6Zn5(MoO4)8 structure, while filling of the cation vacancies by larger Na+ or Ag+ ions plays a destabilizing role. The series A 3Li2R (MoO4)4 shows second harmonic generation effects compatible with that of β′‐Gd2(MoO4)3 and may be considered as nonlinear optical materials with a modest nonlinearity.  相似文献   

10.
Two new isotypic triple molybdates, namely tri­cesium lithium dicobalt tetra­kis­(tetra­oxo­molybdate), Cs3LiCo2(MoO4)4, and tri­rubidium lithium dizinc tetra­kis­(tetra­oxo­molybdate), Rb3LiZn2(MoO4)4, crystallize in the non‐centrosymmetric cubic space group I3d and adopt the Cs6Zn5(MoO4)8 structure type. In the parent structure, the Zn positions have 5/6 occupancy, while they are fully occupied by statistically distributed M2+ and Li+ cations in the title compounds. In both structures, all corners of the (M2/3Li1/3)O4 tetra­hedra (M = Co and Zn), having point symmetry , are shared with the MoO4 tetra­hedra, which lie on threefold axes and share corners with three (M,Li)O4 tetra­hedra to form open mixed frameworks. Large alkaline cations occupy distorted cubocta­hedral cavities with symmetry. The mixed tetra­hedral frameworks in the structures are close to those of mayenite (12CaO·7Al2O3) and the related compounds 11CaO·7Al2O3·CaF2, wadalite (Ca6Al5Si2O16Cl3) and Na6Zn3(AsO4)4·3H2O, but the terminal vertices of the MoO4 tetra­hedra are directed in opposite directions along the threefold axes compared with the configurations of Al(Si)O4 or AsO4 tetra­hedra. The cation arrangements in Cs3LiCo2(MoO4)4, Rb3LiZn2(MoO4)4 and Cs6Zn5(MoO4)8 repeat the structure of Y3Au3Sb4, being stuffed derivatives of the Th3P4 type.  相似文献   

11.
Crystal Structure and Absorptionspectrum of Cs4CuSi2O7, EPR Spectra of K6CuSi2O8 and A4CuSi2O7 (A = Rb, Cs), a Comparison with Egyptian Blue, CaCuSi4O10 Cs4CuSi2O7 is obtained by annealing intimate mixtures of Cs2O, CuO and SiO2 in sealed Ag containers at 500 °C as a greenish-blue powder which is sensitive to moisture. The crystal structure (triclinic, P1) contains chains of [CuSi2O7] with Cu2+ in square-planar coordination. The absorption and EPR spectra of Cs4CuSi2O7, K6CuSi2O8 and Rb4CuSi2O7 are discussed in terms of the Angular-Overlap-Model (AOM) and compared with Egyptian blue, CaCuSi4O10.  相似文献   

12.
New Oxocuprates(I). On Cs3Cu5O4, Rb2KCu5O4, RbK2Cu5O4 and K3Cu5O4 Cs3Cu5O4 light yellow, powder as well as single crystals [a = 10.313(9), b = 7.630(1), c = 14.750(4) Å, β = 106.48(6)°], Rb2KCu5O4 [a = 9.724(2), b = 7.443(0), c = 14.246(2) Å, β = 106.78(8)°], RbK2Cu5O4 [a = 9.561(1), b = 7.411(0), c = 14.111(1) Å, β = 106.76(7)°] and K3Cu5O4 [a = 9.422(1), b = 7.364(1), c = 13.995(2) Å, β = 107.00(2)°] are new prepared. The colour of the powders becomes lighter according to the sequence showed above. K3Cu5O4 shows pale yellow. The Madelung Part of Lattice Energy, MAPLE, is calculated and discussed.  相似文献   

13.
The Antimonide Triantimonidometallates(III) Cs6K3Sb[AlSb3] and Cs6K3Sb[GaSb3] The novel compounds Cs6K3Sb[AlSb3] and Cs6K3Sb[GaSb3] are formed from stoichiometric mixtures of Cs, AlSb (GaSb) and KSb in sealed niobium ampoules at 950 K. The hexagonal structures are especially characterized by one-dimensional rod packings 1∞[Cs6K3Sb] which are formed from columns of condensed (Cs6K6/2) icosahedra. The icosahedra are centered by Sb3-? anions. The trigonal planar anions [AlSb3]6-? and [GaSb3]6-? are embedded between the icosahedra columns, and they are coordinated by alkali metal atoms. The FIR spectra were assigned to the vibrations of the [MSb3]6-? anions, with respect to the 6 m2-D3h symmetry. (P63/mmc, No. 194; a = 1101.7 and 1097.2 pm; c = 1158.9 and 1150.1 pm; Z = 2; Single crystal data: 574 and 546 reflections; R = 0.073 and 0.029. Distances:d(Al? Sb) = 265.4 pm; d(Ga? Sb) = 265.1 pm; d(Sb? Cs) = 401.6–423.0 pm; d(Sb? K) = 358.6–367.3 pm).  相似文献   

14.
Rubidium metaborate, Rb3B3O6, was obtained by the reaction of Rb2CO3 and BN using a radiofrequency furnace at a maximum reaction temperature of 1173 K. The crystal structure has been determined by single‐crystal X‐ray diffraction. The space group is , with all atoms positioned on a twofold axis (Wyckoff site 18e). The ionic compound is isotypic with Na3B3O6, K3B3O6 and Cs3B3O6.  相似文献   

15.
Crystals of cesium silicate Cs6Si10O23 were prepared upon the crystallization of glass Cs2O · 4SiO2. The crystal structure of Cs6Si10O23 was determined by single-crystal X-ray diffraction (space group P $\bar 6$ 2m, a = 9.578(5) Å, c = 4.155(5) Å, Z = 0.5, 269 F(hkl), R = 0.0424). The three-dimensional tetrahedral silicate framework in Cs6Si10O23 is similar to that in Rb6Si10O23 (space group P $\bar 6$ 2m, a = 9.475(5) Å, c = 8.200(5) Å) in which layers formed by 12-membered rings of silicon-oxygen tetrahedra may be distinguished. However, while in the rubidium silicate structure the vertices of the tetrahedra neighboring in a layer point to opposite directions, in cesium silicate these tetrahedra are disordered as regards the arrangement of vertices either upward or downward relative to the layer plane. The random disorder results in a smaller unit cell parameter c in Cs6Si10O23 compared to Rb6Si10O23. The compound melts congruently; the melting temperature and the enthalpy of melting of the crystal are 1208 ± 1 K and 156.2 ± 15 kJ/mol, respectively.  相似文献   

16.
New Oxocobaltates(IV): On K6[Co2O7] K6Co2O7 is another new oxide containing tetravalent Co (red-violet single crystals). According to precession- and WEISSENBERG-photographs the space group is P21/c; a = G.585, b = 9.123. c = 11.479 Å, β = 127.1°. The crystal structure shows Co2O7-groups (two tetrahedron connected by a common corner, symmetry ≈ S6). The Madelung Part of Lattice Energy (MAPLE) is computed and compared with MAPLE of Cs2CoO3. The magnetic properties are reported (measurements of susceptibility by the method of FARADAY in a temperature range of 3–300°K).  相似文献   

17.
Two new mixed alkaline uranyl molybdates CsNa3[(UO2)4O4Mo2O8] ( 1 ) and Cs2Na8[(UO2)8O8(Mo5O20)] ( 2 ) have been obtained by high‐temperature solid state reactions. Their crystal structures have been solved by direct methods: Compound 1 : triclinic, P , a = 6.46(1), b = 6.90(1), c = 11.381(2) Å, α = 84.3(1), β = 91.91(1), γ = 80.23(1)°, V = 488.6(2) Å3, R1 = 0.06 for 2865 unique reflections with |Fo| ≥ 4σF; Compound 2 : orthorhombic, Ibam, a = 6.8460(2), b = 23.3855(7), c = 12.3373(3) Å, V = 1975.2(1) Å3, R1 = 0.049 for 2120 unique reflections with |Fo| ≥ 4σF. The structure of 1 contains complex sheets of UrO5 pentagonal bipyramids and molybdenum polyhedra. The sheets have [(UO2)2O2(MoO5)] composition. Natrium and cesium atoms are located in the interlayer space. Cesium atoms are situated between the molybdenum clusters, whereas natrium atoms are segregated between the uranyl complexes. The large Cs+ ions are localized between the Mo2O9 groups and force the molybdenum polyhedra to rotate relative to the [(UO2)2O2(MoO5)] sheets. Such rotation is impossible for U6+ polyhedra due to their rigid edge‐sharing complexes. The distance between the U6+ polyhedra vertices of neighboring layers is 3.8 Å, that allows the Na+ ion to be positioned between the uranyl groups. The crystal structure of 2 is based upon a framework consisting of [(UO2)2O2(MoO5)] sheets parallel to (010). The sheets are linked into a 3‐D framework by sharing vertices with the Mo(2)O4 tetrahedra, located between the sheets. Each MoO4 tetrahedron shares two of its corners with two MoO6 octahedra in the sheet above, and the other two with MoO6 octahedra of the sheet below. Thus four MoO6 octahedra and one MoO4 tetrahedron form chains of composition Mo5O18. The resulting framework has a system of channels occupied by the Cs+ and Na+ ions.  相似文献   

18.
Cs2(H3O)Pr(CH3COO)6 and Cs2Pr(CH3COO)5: Synthesis, Crystal Structures and Thermolysis. Analogous Acetates with Lanthanum through Terbium Single crystals of Cs2(H3O)Pr(CH3COO)6 are obtained as green plates from an acetic acid solution (≈50%) of Cs2CO3 and Pr(CH3COO)3 · 1,5 H2O. The crystal structure monoclinic, Cm, Z = 2, a = 1 540.4(4), b = 691.3(2), c = 1 221.5(4) pm, β = 104.60(5)°, Vm = 379.1(2) cm3/mol, R = 0.040, Rw = 0.035 was determined from four-circle-diffractometer data. The structure consists of monomeric Pr(CH3COO)3 units, in which Pr3+ is surrounded by nine oxygen atoms. These monomers are linked together to infinite layers parallel (001) by common acetate oxygen atoms with two ?molecules”? of Cs(CH3COO). Together with an additional acetate ion coordinated to one of the Cs+ ions the composition of the layers is [Cs2Pr(CH3COO)6]?. Between these layers H3O+ is located for electroneutrality. Thermal decomposition of Cs2(H3O)Pr(CH3COO)6 was examined with thermoanalytical methods (TG/DTA with coupled gas analysis), Guinier-Simon technique and IR spectroscopy: beginning at 70°C the compound looses water and acetic acid. It decomposes topotactically to Cs2Pr(CH3COO)5. At 270°C this acetate decomposes to Cs2CO3 and Pr2O2CO3 which emits CO2 at 600°C form ing Pr2O3or PrO2?x Single crystals of Cs2Pr(CH3COO)5 were obtained from Pr(CH3COO)3, in molten Cs(CH3COO) at about 200°C. The crystal structure tetragonal, P43, Z = 4, a = 1 174,5(2), c = 1 480,5(3) pm, Vm = pin,307,5(1) cm3/mol, R = 0,061, Rw= 0,031 again consists of Pr(CH3COO)3, monomers where Pr3+ has 9 oxygen ligands in its first coordination sphere. They are linked together by two ”molecules“ of cesium acetate to infinite chains along [00l] around the 4, screw axis. There are also acetate bridges between these chains. Isotypic compounds Cs2(H3O)M(CH3COO)6 and Cs2M(CH3COO)5, and Cs2M(CH3COO)5with M = La? Tb, were obtained from acetic acid solutions or thermal decomposition and were characterized by X-ray Guinier techniques.  相似文献   

19.
New Metal Oxides with Doubles of Tetrahedra as Building Units: Rb6[Tl2O6] and Cs6[In2O6] We prepared the hitherto unknown Rb6[Tl2O6] and Cs6[In2O6] by heating mixtures of Tl2O3 and RbO0.60 (Rb:Tl = 3.5:1) as well as In2O3 and CsO0.53 (Cs:In = 3.5:1) as single crystals [closed Ag-cylinder, 650°C, 14 d]. The single crystals of Rb6[Tl2O6] are yellow, those of Cs6[In2O6] pale yellow, all transparent and rude. The new type of structure was elucidated by 4-circle-diffractometer (PW 1100) data. Rb6[Tl2O6]: P21/a; a = 1145,7(3), b = 713,3(1), c = 783,9(2) pm, β = 93,73° (2), Z = 2; Ag–Kα, 2100 out of 2531 I0(hkl), R = 9,6% and Rw = 8,9%. Cs6[In2O6]: P21/a; a = 1178,5(4), b = 730,7(2), c = 816,3(2) pm, β = 95,38° (3), Z = 2; Mo–Kα, 1584 out of 2032 I0(hkl), R = 9,25%, and Rw = 8,44%. The Madelung Part of Lattice Energy, MAPLE, is calculated and discussed.  相似文献   

20.
Oxidation Products of Intermetallic Compounds. III. Low Temperature Forms of K2Sn2O3 and Rb2Sn2O3 and a Notice about K2Ge2O3 By controlled oxidation of KSn (at 320°C) and RbSn (at 410°C) with O2 the hitherto unknown low temperature forms of K2Sn2O3 (a = 8.4100(8) Å) and Rb2Sn2O3 (a = 8.6368(8) Å) are obtained, which are isotopic with cubic K2Pb2O3. Oxidation at higher temperatures (at 510–5207°C) leads to the well-known HT-forms. The Madelung Part of Lattic Energie, MAPLE, is calculated for both compounds. K2Pb2O3, Rb2Pb2O3, Cs2Pb2O3, and Cs2Sn2O3 have been prepared too by oxidation of KPb, RbPb, CsPb, and CsSn. Oxidation of KGe (at 400°C) leads to the first oxogermanate(II), K2Ge2O3 (cubic a = 8.339(1) Å, isotypic with K2Pb2O3) together with K6Ge2O7.  相似文献   

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