Abstract:

Mixed anion compounds can generate the emergence of novel properties that differ from those with mono-type anion due to the difference of electronegativities, ionic radii, polarizabilities, and oxidation states between unlike anions. Abundant research has been conducted on metallic mixed-anion materials with potential application in electronics, detectors of moisture, gas sensors, electrodes for solar batteries, etc. The flux method has been widely applied for mixed-anion crystal growth, which based on metathetical reaction with appropriate metal-salts ?ux under mild conditions. It is meaningful to synthesize the mixed anion compounds by the flux method. Single crystals of tungsten oxychloride Li₂₃CuW₁₀O₄₀Cl₅ were prepared via CuCl₂ flux-growth method by two steps, which using high quality and phase-pure polycrystalline Li₄WO₅ as precursor. The crystal structure was determined by single-crystal X-ray diffraction analysis, which indicates that Li₂₃CuW₁₀O₄₀Cl₅ crystallizes in P6₃/mcm space group (a= 1.02846(3) nm, c=1.98768(9) nm, V=1.82076(11) nm ³, and Z=2). There are crystallographically independent five Li, two W, one Cu, two Cl, and five O atoms in the unit cell, where W(1) atoms are coordinated with one Cl and five O atoms in a distorted octahedra geometry, while W(2) atoms are connected with four O atoms in a tetrahedral coordination. The Cu atoms are connected with six O atoms forming [CuO₆] octahedra. Thus, the crystal structure of the titled compound consists of [CuO₆] and [W(1)O₅Cl] octahedra, and [W(2)O₄] tetrahedra. The successful synthesis of tungsten oxychloride Li₂₃CuW₁₀O₄₀Cl₅ through flux-growth method is meaningful for explore new mixed anion compounds in future.

Key words: tungsten oxychloride, CuCl₂ flux, crystal structure, X-ray diffraction