Synthesis,Crystal Structure,and Characterization of Na7Cu4(AsO4)5

Abstract

Sodium copper (II) arsenate Na₇Cu₄(AsO₄)₅ has been grown by conventional high-temperature, solid-state methods in molten-salt media. It was characterized by single crystal X-ray diffraction (XRD), thermal analysis (DTA–TGA), scanning electron microscopy (SEM), semiquantitative energy dispersive spectroscopy analysis (EDS), and vibrational spectroscopy. Na₇Cu₄(AsO₄)₅ exhibits a three-dimensional framework built up of CuO₅, CuO₄, and AsO₄ polyhedra, with intersecting channels in which the Na⁺ cations are located. The three-dimensional cohesion of the framework results from Cu–O–As bridges. CuO₅ and CuO₄ polyhedra are elongated due to the Jahn–Teller effect, whereas AsO₄ tetrahedra are almost regular. This new structural model is validated by the charge distribution (CD) analysis. The infrared and Raman spectra confirmed the presence of AsO₄ tetrahedra.

[Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional tables and figures.]     

SYNTHESIS,CHARACTERIZATION, AND CRYSTAL STRUCTURE OF A NOVEL DECAVANADATE Mg(H2O)6(C6H14N2)2V10O28·8H2O

Journal of Structural Chemistry - A novel decavanadate salt Mg(H2O)6(C6H14N2)2V10O28·8H2O is obtained by the reaction of vanadium oxide and 1,4-diazabicyclo [2.2.2] octane (DABCO). The title...     

Preparation and Characterization of [Zn(H2O)6][Zn2V10O28(H2O)10]?·?6H2O Single Crystals with a Novel Metallic Heteropolyoxoanion

Abstract  The compound investigated in this study contains a novel centrosymmetric heteroanion [Zn₂V₁₀O₂₈(H₂O)₁₀]²⁻. This cluster results from the connection between a V₁₀O₂₈ group and two Zn(2)O(OH₂)₅ octahedra. The Zn(1)O₆ octahedron and three water molecules associated with it are located between the different layers. The [Zn(H₂O)₆][Zn₂V₁₀O₂₈(H₂O)₁₀] · 6H₂O compound belongs to P-1 space group, with a = 8.967(2) ?, b = 10.390(4) ?, c = 12.338(13) ?, α = 108.31(7)°, β = 100.68(7)°, γ = 103.00(3)°, V = 1022(1) ?³ and Z = 1. Refinement gave R = 0.035 and wR(F²) = 0.098 for 3837 unique observed reflexions [I > 2σ(I)]. Index Abstract  The compound investigated in this study contains a novel centrosymmetric heteroanion [Zn₂V₁₀O₂₈(H₂O)₁₀]²⁻. This cluster results from the connection between a V₁₀O₂₈ group and two Zn(2)O(OH₂)₅ octahedra.      

Synthesis and crystal structure determination of yttrium ultraphosphate YP5O14

The crystal structure of monoclinic YP₅O₁₄ (space group C2/c, a=12.919(2) Å, b=12.796(4) Å, c=12.457(2) Å, β=91.30(1)°, Z=8) has been refined from single-crystal X-ray diffraction data. Full-matrix least-squares refinement on F² using 2249 independent reflections for 183 refinable parameters results in a final R value of 0.027 (ωR=0.069). The structure is isotypic with HoP₅O₁₄. This structure is built up from infinite layers of PO₄ tetrahedra linked through isolated YO₈ polyhedra. The three-dimensional cohesion of the framework results from Y-O-P bridges. This crystal structure refinement leads to the calculated X-ray diffraction powder pattern of this monoclinic polymorph, which has been the starting point of a thorough study of the solid-state synthesis of this ultraphosphate. This investigation further leads to a better outstanding of features observed during the synthesis of powdered samples. The thermal behavior of this ultraphosphate has been studied by DTA and TGA analyses. The infrared and Raman spectroscopic characterizations have been carried out on polycrystalline samples. The luminescence properties of the Eu³⁺ ion incorporated in the monoclinic C2/c polymorph of YP₅O₁₄ as local structural probe show that in YP₅O₁₄: 5% Eu³⁺ sample, the Eu³⁺ ions are distributed over the two Y³⁺ crystallographic sites of C₂ symmetry of this structure.