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1.
The systems Rb2MoO4-R2(MoO4)3-Hf(MoO4)2 have been investigated in the subsolidus region by X-ray powder diffraction, DTA, and IR spectroscopy. Triple molybdates of the composition 5: 1: 2 are formed in the systems with R = Al, In, Sc, and Fe. Molybdates of composition 5: 1: 3 and 1: 1: 1 are found in the iron(III)-containing system in addition to the 5: 1: 2 molybdate. Single crystals of the double molybdate RbFe(MoO4)2, which is formed in the Rb2MoO4-Fe2(MoO4)3 system, have been grown. The structure of this double molybdate has been refined using X-ray diffraction data (X8 APEX automated diffractometer, MoK α radiation, 373 F(hkl), R = 0.0287). The trigonal unit cell parameters are the following: a = b = 5.6655(2) Å, c = 7.5061(4) Å, V = 208.65(1) Å3, Z = 1, ρcalc = 3.670 g/cm3, space group R3m1. The structure is formed by layers of FeO6 octahedra sharing corners with MoO4 tetrahedra and RbO12 icosahedra.  相似文献   

2.
The subsolidus region of the Ag2MoO4-CoMoO4-Al2(MoO4)3 ternary salt system was studied by X-ray powder diffraction analysis. New compounds Ag1?x Co1?x Al1 + x (MoO4)3 (0 ≤ x ≤ 0.4) and AgCo3Al(MoO4)5 were detected to form. The variable-composition phase Ag1?x Co1?x Al1 + x (MoO4)3 is of the NASICON structure type (space group \(R\bar 3c\) ). AgCo3Al(MoO4)5 crystallizes in the triclinic symmetry (space group \(P\bar 1\) Z = 2) with the unit cell parameters a = 6.9101(6), b = 17.519(1), c = 6.8241(6) Å, α = 87.356(7)°, β = 101.078(7)°, and γ = 91.985(9)°. The compounds are thermally stable until 770–780 and 760°C, respectively.  相似文献   

3.
A ternary salt system Rb2MoO4-Ce2(MoO4)3-Zr(MoO4)2 is studied by powder XRD. Single crystals of 5:1:2 ternary rubidium-cerium-zirconium molybdate Rb5CeZr(MoO4)6 are obtained by solution melt crystallization under spontaneous nucleation conditions. The crystal structure is solved by X-ray crystallography (X8 APEX automated diffractometer, MoK ?? radiation, 1274 F(hkl), R = 0.0456). The parameters of a trigonal unit cell are: a = b = 10.7248(2) ?, c = 38.796(1) ?, V = 3864.52(14) ?3, Z = 6, $R\bar 3c$ space group. The three-dimensional complex framework comprises Mo tetrahedra linked to two independent (Ce,Zr)O6 octahedra. Two types of rubidium atoms occupy large cavities of the framework.  相似文献   

4.
The Tl2MoO4-Nd2(MoO4)3-Hf(MoO4)2 system was studied in the subsolidus region using X-ray powder diffraction. New triple molybdates were found to exist in this system: Tl5NdHf(MoO4)6 (5: 1: 2), TlNdHf0.5(MoO4)3 (1: 1: 1), and Tl2NdHf2(MoO4)6.5 (2: 1: 4). The first TlNd(MoO4)2 single crystals were grown from melt solutions with spontaneous nucleation. Their crystal structure was refined from X-ray diffraction data (Bruker X8 Apex automated diffractometer, MoK α radiation, 386 F(hkl), R = 0.0136). The tetragonal unit cell parameters are as follows: a = 6.3000(2) Å, c = 9.5188(5) Å, V = 377.80(3) Å3, Z = 2, ρcalcd = 5.876 g/cm3, space group P4/nnc. The structure is a framework built of NdO8 and TlO8 tetragonal antiprisms linked via shared lateral edges and alternating in the checkerboard order. Layers share oxygen vertices with MoO4 interlayer tetrahedra and are linked into the framework.  相似文献   

5.
In the samples of the Na2MoO4-MgMoO4 system quenched in the air at above 600°C, by powder X-ray diffraction two double molybdates of variable composition are detected: monoclinic alluaudite-like Na4?2x Mg1+x (MoO4)3 (0.05 ≤ x ≤ 0.35) and triclinic Na2?2y Mg2+y (MoO4)3 (0.10 ≤ y ≤ 0.40) isostructural to previously studied Na2Mg5(MoO4)6. Sodium-magnesium molybdate of the Li3Fe(MoO4)3 structure type is not revealed in this system. By spontaneous flux crystallization, the crystals are obtained and the structures of two triclinic double molybdates of the Na2Mg5(MoO4)6 structure type (space group $P\bar 1$ , Z = 1) containing magnesium and manganese are determined. The results of the refinement of site occupancies made it possible to determine the composition of the studied crystals: for the compound with magnesium (Na)0.5(Na0.2550.745)(Na0.755Mg0.245)Mg2(MoO4)3 or Na1.51Mg2.245(MoO4)3 (a = 6.9577(1) Å, b = 8.6330(2) Å, c = 10.2571(2) Å, α = 106.933(1)°, β = 104.864(1)°, γ = 103.453(1)°, R = 0.0188); for the compound with manganese (Na)0.5(Na0.330.67)(Na0.83Mn0.17)Mn2(MoO4)3 or Na1.64Mn2.17(MoO4)3 (a = 7.0778(2) Å, b = 8.8115(2) Å, c = 10.4256(2) Å, α = 106.521(1)°, β = 105.639(3)°, Γ = 103.233(1)°, R = 0.0175). The Na2Mg5(MoO4)6 structure is redetermined and it is shown that actually it corresponds to the composition Na1.40Mg2.30(MoO4)3.  相似文献   

6.
The subsolidus region of the Cs2MoO4-Bi2(MoO4)3-Zr(MoO4) system was studied by X-ray powder diffraction. Quasi-binary sections were elucidated, and triangulation performed. Triple molybdates with the component ratios 5: 1: 2 (S 1) and 2: 1: 4 (S 2) were prepared for the first time. Crystals of cesium bismuth zirconium molybdate of the 5: 1: 2 stoichiometry (Cs5BiZr(MoO4)6) were grown from fluxed melts with spontaneous nucleation. The composition and crystal structure of this triple molybdate were refined using X-ray diffraction data (collected on X8 APEX automated diffractometer, MoK α radiation, 2348 F(hkl), R = 0.0226). The trigonal unit cell parameters were as follows: a = b = 10.9569(2), c = 39.804(4) Å, V = 4138.4(4) Å3, Z = 6, space group R $ \bar 3 The subsolidus region of the Cs2MoO4-Bi2(MoO4)3-Zr(MoO4) system was studied by X-ray powder diffraction. Quasi-binary sections were elucidated, and triangulation performed. Triple molybdates with the component ratios 5: 1: 2 (S 1) and 2: 1: 4 (S 2) were prepared for the first time. Crystals of cesium bismuth zirconium molybdate of the 5: 1: 2 stoichiometry (Cs5BiZr(MoO4)6) were grown from fluxed melts with spontaneous nucleation. The composition and crystal structure of this triple molybdate were refined using X-ray diffraction data (collected on X8 APEX automated diffractometer, MoK α radiation, 2348 F(hkl), R = 0.0226). The trigonal unit cell parameters were as follows: a = b = 10.9569(2), c = 39.804(4) ?, V = 4138.4(4) ?3, Z = 6, space group R c. The mixed-metal three-dimensional framework in this structure is built of Mo tetrahedra and two sorts of (Bi,Zr)O6 octahedra. Large interstices accommodate two sorts of cesium atoms. The Bi3+ and Zr4+ cation distributions over two positions were refined during structure solution. Original Russian Text ? B.G. Bazarov, T.V. Namsaraeva, R.F. Klevtsova, A.G. Anshits, T.A. Vereshchagina, R.V. Kurbatov, L.A. Glinskaya, K.N. Fedorov, Zh.G. Bazarova, 2008, published in Zhurnal Neorganicheskoi Khimii, 2008, Vol. 53, No. 9, pp. 1585–1589.  相似文献   

7.
Binary molybdates K4M2+ (MoO4)3 (M2+=Mg, Mn, Co) isostructural to triclinic \ga-K4Zn(WO4)3 were synthesized, and optimal conditions for their spontaneous crystallization were found. It was established by XRPA and DTA that at 530°C the structure of the compound with cobalt undergoes a transition to the orthorhombic structure of K4Zn(MoO4)3. The structure of K4Mn(MoO4)3 was determined from single crystal diffraction data (a=7.613, b=9.955, c=10.156 Å,α=92.28,β=106.66,γ=105.58°, Z=2, space group $P\bar 1$ , R=0.030). In this compound, Mn has a higher coordination number (CN=5+1) than that of Zn inα-K4Zn(WO4)3 (CN=4+1). The main structural feature is pairs of MnO6 octahedra linked by the bridging MoO4 tetrahedra into ribbons stretching along the a axis. The structure is compared with related structures of binary molybdates and other members of the alluaudite family.  相似文献   

8.
A new representative of the Rb2U2MoO10 uranomolybdate series, was synthesized; its single crystals were grown and studied by X-ray diffraction. The atomic crystal structure was solved: monoclinic system, space group P21/c, a = 8.542(1) Å, b = 15.360(2) Å, c = 8.436(1) Å, b = 104.279(3)°, R 1 = 0.064 for 1817 independent reflections with F > 4σ(F). The crystal structure is built of negatively charged infinite corrugated [U2MoO10] 2∞ δ? layers, which are linked through rubidium cations arranged between them. The compound was studied by IR spectroscopy; the absorption bands in the spectrum were assigned.  相似文献   

9.
Systems Tl2MoO4-E(MoO4)2 (E = Zr, Hf) are studied using X-ray powder diffraction, DTA, and IR spectroscopy. Compounds Tl8E(MoO4)6 and Tl2E(MoO4)2 are found in these systems. T-x diagrams for the Tl2MoO4-Zr(MoO4)2 system are designed. Single crystals are grown and structure is solved for Tl8Hf(MoO4)6. The compound crystallizes in a monoclinic structure with the unit cell parameters a = 9.9688(6) Å, b = 18.830(1) Å, c = 7.8488(5) Å, β = 108.538(1)°, Z = 2, space group C2/m. The main structural fragment is a [HfMo6O24]8? isle group. Three crystallographically independent types of Tl polyhedra uniformly fill spaces between [HfMo6O24]8? fragments to form a three-dimensional framework.  相似文献   

10.
The enthalpies of formations of Ce2(MoO4)3(s) and Sm2(MoO4)3(s) have been measured at 298.15 K using semi adiabatic solution calorimetry. The precipitation reaction between RE(NO3)3·6H2O(s) (R= Ce, Sm) and ammonical solution of Na2MoO4(s) was studied. From the enthalpy of precipitation and other required auxiliary data, $ \Updelta_{\text{f}} H_{\text{m}}^{ \circ } \left( { 2 9 8. 1 5 {\text{ K}}} \right) $ Δ f H m ° ( 2 9 8.1 5 K ) of Ce2(MoO4)3(s) and Sm2(MoO4)3(s) have been calculated for the first time as ?4388.7 ± 3.6 and ?4363.4 ± 4.1 kJ mol?1, respectively. The enthalpy of hydration of anhydrous Ce(NO3)3(s) to Ce(NO3)3·6H2O(s) has been calculated. $ \Updelta_{\text{f}} H_{\text{m}}^{ \circ } \left( {{\text{MoO4}}^{ 2- } ,\,{\text{aq}},\, 2 9 8. 1 5 \,{\text{K}}} \right) $ Δ f H m ° ( MoO4 2 ? , aq , 2 9 8.1 5 K ) has also been measured and calculated as ?995.1 kJ mol?1 from required literature data.  相似文献   

11.
Phase equilibria in the systems M2MoO4-Cr2(MoO4)3-Zr(MoO4)2 (M = Li, Na, or Rb) were investigated by X-ray powder diffraction analysis, DTA, and IR spectroscopy. The subsolidus structure of the phase diagrams of the systems under study was established. Two phases are formed in the Rb2MoO4-Cr2(MoO4)3-Zr(MoO4)2 system with the molar ratios of the starting components equal to 5: 1: 1 (S 2) and 1: 1: 1 (S 1). Proceeding from that the isostructurality of Rb5FeHf(MoO4)6 and S 2 the unit cell, parameters are determined for S 2.  相似文献   

12.
Complex rare-earth molybdophosphates of sodium and potassium (Na2Yb(PO4)(MoO4) (I) and K2Yb(PO4)(MoO4) (II) are synthesized by solid-phase reactions at 600°C (for I) and 750°C (for II). The molybdophosphates are characterized using powder X-ray diffraction, laser second harmonic generation (SHG), IR spectroscopy, and differential thermal analysis. Their structures are refined using the Rietveld technique. The compounds are isostructural and crystallize in an orthorhombic system (space group Ibca, Z = 8). The unit cell parameters are a = 18.0086(1) Å, b = 12.0266(1) Å, c = 6.7742(1) Å for compound I and a = 19.6646(1) Å, b = 12.0570(1) Å, c = 6.8029(1) Å for compound II. The structures are built of YbO8 chains extended along axis c and linked into layers through PO4 tetrahedra. The Na+ cations (CN = 6) and the K+ cations (CN = 8) reside in the interlayer spaces.  相似文献   

13.
A ternary salt system Rb2MoO4-Eu2(MoO4)3-Hf(MoO4)2 was studied in the subsolidus area by X-ray phase analysis. A novel ternary molybdate, Rb4.98Eu0.86Hf1.11(MoO4)6, formed in the system. The Rb4.98Eu0.86Hf1.11(MoO4)6 rubidium-europium-hafnium molybdate crystals were grown by solution-melt crystallization under the spontaneous nucleation conditions. The structure and composition of this compound were refined by single crystal X-ray diffraction (X8 APEX automated diffractometer, MoK α radiation, 1753 F(hkl), R = 0.0183). The crystals are trigonal, a = b = 10.7264(1) Å, c = 38.6130(8) Å, V = 3847.44(9) Å3, Z = 6, space group R \(\bar 3\) c. The three-dimensional mixed framework of the structure comprises Mo tetrahedra and two types of octahedra, (Eu,Hf)O6 and HfO6. The large cavities of the framework include two types of the rubidium atom. The distribution of the Eu3+ and Hf4+ cations over two crystallographic positions was refined.  相似文献   

14.
An X-ray diffraction study of the single crystals of (C2H7N4O)2[(UO2)2(OH)2(C2O4)(CHO2)2] was carried out. The compound crystallizes in the triclinic system, space group $P\bar 1$ , Z = 2, a = 5.5621(8) Å, b = 8.1489(10) Å, c = 11.8757(16) Å, α = 88.866(7)°, β = 82.204(6)°, γ = 87.378(6)°, V = 532.7(1) Å3, ρcalcd = 2.988 g/cm3. The main structural units in the crystal are the [(UO2)2(OH)2(C2O4)(CHO2)2)]2? chains corresponding to the crystal chemical group A2M 2 2 K02M 2 1 (A = UO 2 2+ , M2 = OH?, K02 = C2O 4 2? , M1 = CHO 2 ? ) of uranyl complexes. The chains are united into a three-dimensional framework through the electrostatic interaction and hydrogen bonds involving uranyl, oxalate, and hydroxyl groups, formate ions, and 1-carbamoylguanidinium cations.  相似文献   

15.
Single crystals of molybdate Tl2Mg2(MoO4)3 are grown, and its crystal structure is refined in an X-ray diffraction experiment (an automated diffractometer, MoK α radiation, 914 F(hkl) reflections, R = 0.0459). The crystal are cubic with a = b = c = 10.700(1) Å, V = 1225.0(2) Å3, Z = 4, space group P213. The mixed 3D framework of the structure is built of MoO4 tetrahedra and two types of corner-sharing MgO6 octahedra. Two types of thallium atoms occupy large interstices.  相似文献   

16.
(CN3H6)2[UO2CrO4(C5H3N(COO)2)] crystals (where CN3H6 is the guanidinium cation and C5H3N(COO)2 is the pyridine-2,6-dicarboxylate anion) have been synthesized and studied by X-ray diffraction and IR spectroscopy. The compound crystallizes in triclinic system with the unit cell parameters a = 7.4115(3) Å, b = 10.0365(7) Å, c = 12.1822(10) Å, α = 93.992(6)°, β = 97.749(7)°, γ = 96.907(6)°; space group $P\bar 1$ , Z = 2, R = 0.0721. The structure consists of [UO2CrO4(C5H3N(COO)2)] 2 4? , centrosymmetric dimers linked with the outer-sphere guanidinium ions by means of electrostatic interactions and hydrogen bonds. [UO2CrO4(C5H3N(COO)2)] 2 4? dimers belong to the AT001B2 crystallochemical group (A = UO 2 2+ , T001 = C5H3N(COO) 2 2? B2 = CrO 4 2? ) of uranyl complexes. Using molecular Voronoi-Dirichlet polyhedra, we have established that, in addition to hydrogen bonds, the π-π stacking interaction also produces some effect on the packing of uranyl-containing complexes in the studied structure.  相似文献   

17.
The synthesis of $(\mu - H)(\mu - \eta ^2 - H_2 )_4 )Os_3 (CO)_{10} $ (4) from piperidine and Os3(CO)10(CH3CN)2 and its solid state structure are reported. The room temperature reactions of the decarbonylation product of4, $(\mu - H)(\mu _3 - \eta ^2 - H_2 )_4 )Os_3 (CO)_9 $ (3), with P(C6H5)3, CNCH3, HCl and H2 are reported. Overall, the products obtained closely resemble those obtained from the analogous, $(\mu - H)(\mu _3 - \eta ^2 - H_2 )_3 )Os_3 (CO)_9 $ (1). The isomerizations of the phosphine addition products $(\mu - H)(\mu - \eta ^2 - H_2 )_n )Os_3 (CO)_9 P(C_6 H_5 )_3 $ (n = 3,6a;n = 4,5a) have been studied by1H-NMR techniques and the initial rearrangement was shown to be an intramolecular process. Slower conversion to the complex $(\mu - H)(\mu _3 - \eta ^2 - H_2 )_4 )Os_3 (CO)_8 P(C_6 H_5 )_3 $ (8) was observed and the solid state structure of this product is reported and compared with a related compound containing an ethyl,n-propylμ 3-imidoyl ligand. Compound4 crystallizes in the triclinic space group Pl (#2) withZ= 2, and unit cell parametersa = 9.294(3) Å,b = 15.758(5) Å,c = 7.406(2) Å,a = 81.10(2)°,β=76.47(2)°,y =74.88(2)°, andV =1013(l) Å3. Least-squares refinement of 2677 reflections gave a final discrepancy factor ofR = 0.054 (R w = 0.066). Compound8 crystallizes in the space group C2/c with unit cell parametersa = 24.818(3) Å,b = 16.389(3) Å,c = 18.111(3) Å,β= 120.94(2)°,V = 6318(4) Å3, andZ = 8. Least squares refinement of 3439 reflections gave a final discrepancy factor ofR = 0.039 (R w =0.047).  相似文献   

18.
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   

19.
Anhydrous and partially hydrated acid trinuclear trifluoroacetates of divalent transition metals of the composition [M3(CF3COO)6(CF3COOH)6)](CF3COOH) and [M3(CF3COO)6(CF3COOH)2(H2O)4)](CF3COOH)2, respectively, where M = Co (I, III) Ni (II, IV), were synthesized and studied by X-ray diffraction. Complexes I and II were obtained by crystallization from solutions of M(CF3COO)2 · 4H2O in trifluoroacetic anhydride; complexes III and IV were synthesized under the same conditions with the use of 99% trifluoroacetic acid as a solvent. Crystals I are triclinic: space group $P\bar 1$ , a = 13.199(6) Å, b = 14.649(6) Å, c = 15.818(6) Å, α = 90.04(4)°, β = 114.32(4)°, γ = 108.55(4)°, V = 2611.3(19) Å3, Z = 2, R = 0.0480. Crystals II are trigonal: space group $R\bar 3$ , a = 13.307(2) Å, c = 53.13(1) Å, V = 8148(2) Å3, Z = 6, R = 0.1112. Crystals III are triclinic: space group $P\bar 1$ , a = 9.001(8) Å, b = 10.379(9) Å, c = 12.119(9) Å, α = 83.67(5)°, β = 72.33(5)°, γ = 83.44(5)°, V = 1068.3(15) Å3, Z = 1 Å, R = 0.1031. Crystals IV are triclinic: space group $P\bar 1$ , a = 9.121(18) Å, b = 10.379(2) Å, c = 12.109(2) Å, α = 84.59(3)°, β = 72.20(3)°, γ = 82.80(3)°, V = 1080.94(40) Å3, Z = 1, R = 0.0334.  相似文献   

20.
The crystals of {Rb11[Cu 2 1 ( H2O)2]}[Cu 15 1 Cl24(CuIICl6)] (I) formed in the RbCl-CuCl-H2O -( O2, C2H2 ) system were studied by X-ray diffraction analysis and ESR spectroscopy. The cell is monoclinic, space group B2/m, Z = 2, a = 24.787(3), b = 13.126(2), c = 11.318(5) Å, γ = 122.36(1)? (DARCH automatic diffractometer, γ(MoKgα). The crystal structure of compound I is a guest-host type structure consisting of the {[Cu 15 1 Cl24Cu11Cl6]13?}n anion layers oriented perpendicularly to the [010] direction and containing large octahedral cavities (edge length =12 Å) with a discrete [ CuIICl6 ] octahedron lying inside the cavity. The Rb+ cations and the charged [Cu 2 1 ( H2O)2]2+ guest species lie between the anion layers. The effect of the nature of the guest on host structure formation is considered using compounds I and Rb11[Cu 15 1 Cl16Brd6CuIICl6 ) Cu-C=CH] as examples.  相似文献   

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