由于不同阴离子之间的电负性、离子半径、极化率和氧化态之间的差异, 混合阴离子化合物可以产生不同于单一类型阴离子的新特性。混合阴离子金属材料在电子、湿度探测器、气体传感器、太阳能电池电极等领域有着广泛的应用前景。助熔剂方法是一种广泛应用于混合离子晶体生长的方法, 它以适当的金属盐作为助熔剂, 在较温和的条件下进行复分解反应。助熔剂法在混合阴离子化合物的合成中具有重要意义。钨氧氯化合物Li₂₃CuW₁₀O₄₀Cl₅单晶以高质量的Li₄WO₅为前驱体, 以CuCl₂为助熔剂通过两步法合成。通过X射线单晶衍射确定其晶体结构。结果表明, Li₂₃CuW₁₀O₄₀Cl₅结晶属于P6₃/mcm空间群, 晶胞参数分别为a=1.02846(3) nm, c=1.98768(9) nm, V=1.82076(11) nm³, Z=2。单胞中分别包含五个晶体学独立的Li原子, 两个W原子, 一个Cu原子, 两个Cl原子以及五个O原子。结构中, W(1)原子和一个Cl原子及五个O原子相连接, 形成畸变八面体, 而W(2)原子与四个O原子相连接形成四面体, Cu原子与六个O原子相连形成八面体。因此, Li₂₃CuW₁₀O₄₀Cl₅的晶体结构主要由[CuO₆]和[W(1)O₅Cl]八面体以及[W(2)O₄]四面体构成。助熔剂法合成钨氧氯化合物Li₂₃CuW₁₀O₄₀Cl₅对今后探索新型的混合阴离子化合物具有重要意义。

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.