- 作者: 王素蘭 ; 許桂芳
- 作者服務機構: 清華大學化學系
- 中文摘要: A new vanadyl(IV) arsenate, K/sub 2/ [ (VO)/sub 2/(AsO/sub 4/)(HAsO/sub 4/)(H/sub 2/AsO/sub 4/)(H/sub 2/O) ].bcdot.0.5H/sub 2/O, has been synthesized hydrothermally at 230.degree.C and structurally characterized by single- crystal X-ray diffraction. The compound crystallizes in triclinic space group P.1bar. with a=6.533(2).ANG., b=9.062(3).ANG., c=12.582(5).ANG., .alpha.=106.29(3),.beta.=98.64(3), .gamma.=103.09(2).degree., V=678.0(4).ANG./sup 3/, Z=2 and R=0.0428 for 2114 unique reflections. The structure consists of V/sup IV/O/sub 6/ octahedra and tetrahedra of AsO/sub 4//sup 3-/, HAsO/sub 4//sup 2-/, and H/sub 2/AsO/sub 4//sup -/ groups to form layers along the [ 001 ] direction with K/sup +/ cations between the layers. Building units of the layers are 4-connected ribbons connected to each other by dihydrogen arsenate groups to form large tunnels perpendicular to the layers. Cations and water molecules reside in the tunnels. The title compound is isotypic with phosphate K/sub 2/( VO)/sub 2/(P/sub 3/O/sub 9/)(OH)/sub 3/.bcdot.1.125H/sub 2/O, that was synthesized at 450.degree.C. In contrast to the phosphate, tetrahedra of three groups, AsO/sub 4//sup 3-/, HAsO/sub 4//sup 2-/, and H/sub 2/AsO/sub 4//sup -/, were distinctly identified in the arsenate. The sites for lattice water are essentially fully occupied due to the larger space provided by the framework of K/sub 2/ [ (VO)/sub 2/(AsO/sub 4/)(HAsO/sub 4/)(H/sub 2/AsO/sub 4/)(H/sub 2/O) ].bcdot.0.5H/sub 2/O. The structures of this arsenate and K/sub 2/(VO)/sub 2/(P/sub 3/O/sub 9/)(OH)/sub 3/.bcdot.1.125H/sub 2/O are discussed.
- 英文摘要: --
- 中文關鍵字: Vanadyl Arsenate; Crystal Structure; Hydrothermal Synthesis; X- Ray Diffraction; Potassium Ion
- 英文關鍵字: 氧釩砷酸;晶體結構;水熱合成;X射線繞射;鉀離子