Hydrothermal Synthesis and Crystal Structures of Two Copper Vanadium Phosphates: CU0.5[VOPO4] · 2H2O and Cu0.5(OH)0.5[VOPO4] · 2H2O
1995; Elsevier BV; Volume: 117; Issue: 1 Linguagem: Inglês
10.1006/jssc.1995.1259
ISSN1095-726X
AutoresYiping Zhang, Abraham Clearfield, Robert C. Haushalter,
Tópico(s)Crystal Structures and Properties
ResumoTwo layered copper vanadium phosphates, Cu0.5[OPO4] · 2H2O (1) and Cu0.5(OH)0.5[VOPO4] · 2H2O (2), have been synthesized hydrothermally and their structures determined by single-crystal X ray crystallography. Phosphate 1 is monoclinic, space group P 21/m, a = 6.614 (2) Å, b = 8.930 (2) Å, c = 9.071 (2) Å, β = 103.79 (2)°, Z = 4, V = 520.3 (3) Å3. Refinement with 750 observed reflections for which I ≥ 3 σ (I) gave R (RW) = 0.051 (0.058). The structure has hydrated Cu2+ ions bonded to layers composed of distorted VO6 octahedra and PO4 tetrahedra. Each Cu2+ ion is bonded to only one layer and possesses a nearly square planar geometry but with two very long axial bonds. This results in a very distorted octahedral configuration composed of two phosphate oxygens, three water molecules, and one vanadyl oxygen. Phosphate 2 is triclinic, space group P1̄ , a = 7.0124 (8) Å, b = 12.6474 (9) Å, c = 6.3022 (6) Å, α = 90.079 (8)°, β = 96.076 (9)° γ = 74.002 (7)°, Z = 2, V = 534.05 (9) Å3. Refinement using 2311 observed reflections with I ≥ 3 σ (I) gave R (RW) = 0.035 (0.043). The structure consists of VOPO4 layers somewhat similar to those of 1, but with the layers bridged together through Cu dimers of Cu2(OH)2(H2O)4. Each Cn2+ ion is in a distorted square planar configuration.
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