Synthesis and characterization of mixed metal organic-inorganic hybrid compounds with a pillared layer structure: CuVO₂(4,4′-bpy)(XO₄) (X = P, As)

Two mixed metal organic-inorganic hybrid compounds, CuVO₂(4,4′-bpy)(PO₄), 1, and CuVO₂(4,4′-bpy)(AsO₄), 2, have been synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction. The two compounds are isostructural and crystallize in the monoclinic space group C2/c (No. 15) with a=21.941(2)Å, b=8.0915(7)Å, c=15.856(1)Å, β=110.424(2)°, Z=8, and R₁=0.037 for 1, and a=21.923(2)Å, b=8.2447(9)Å, c=16.176(2)Å, β=110.967(2)°, Z=8, and R₁=0.041 for 2. The structure consists of bimetallic oxide layers covalently linked through 4,4′-bpy pillars into a 3D framework. Each oxide layer is constructed from corner-sharing VO₄ and PO₄ tetrahedra and CuN₂O₃ square pyramids. On the basis of magnetic susceptibility study of 1, bond-valence calculation and the presence of dioxovanadium unit, the Cu atom is divalent and the V atom is pentavalent.