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化学学报
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化学学报 ›› 2002, Vol. 60 ›› Issue (11): 1999-2003. 上一篇    下一篇

研究论文

高度对称的氟代锗酸盐超分子化合物(NH_4)_2GeF_6·H_2O的溶剂热合成及其晶体结构

陈延民;王树涛;王恩波   

  1. 东北师范大学化学学院,长春(130024)
  • 发布日期:2002-11-15

Solvothermal Synthesis and Crystal Structure of a High Symmetric Supermolecular Fluorogermanate (NH_4)_2GeF_6·H_2O

Chen Yanmin;Wang Shutao;Wang Enbo   

  1. Department of Chemistry, Northeast Normal University,Changchun (130024)
  • Published:2002-11-15

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化合物(NH_4)_2GeF_6·H_2O由GeO_2,NH_4VO_3和HF在吡啶-水体系中低温溶剂 热条件下合成，并用IR、元素分析、TG-DTA和X射线单晶衍射进行了表征。化合物 属立方晶系，空间群为Fm3m, a=0.9118(2)nm,β=90°，V=0.7580(3)nm~3,Z=1, D_c=2.021g/cm~3,F(000)=432,R_1=0.0612, wR_2=0.1510。晶体结构中包含4个 GeF_6,4个H_2O和8个孤立的NH_4~+离子。其中晶格水的引入导致了GeF_6~(2-)八面 体为O_h对称性；进而GeF_6和H_2O通过强烈的F…H-O氢键链接成-3D具有0. 6559nm*0.6559nm*0.6559nm空腔的栅格状骨架的超分子(NH_4)_2GeF_6·H_2O化合 物。NH_4~+位于栅格的中心，以静电引力与GeF_6~(2-)作用，进一步稳定了3D超分 子网络。

关键词: 锗酸盐, 铵化合物, 氟化合物, 晶体结构, 超分子结构, 氢氟酸$吡啶

(NH_4)_2GeF_6·H_2O is obtained as light-green single crystal from the low-temperature solvothermal reaction of GeO_2, NH_4VO_3 and HF in pyridine-water and characterized by the IR, elemental analysis, TG-DTA and single crystal X-ray diffraction. It crystallizes into cubical system, space group Fm3m, a = 0.9118(2) nm, β = 90 °, V = 0.7580 (3) nm~3, Z = 1, D_c = 2.021 g/cm~3, F(000) = 432, R_1 = 0.0612, wR_2 = 0. 1510 for 357 reflections. The structure of the title compound consists of four GeF_6~(2-) units, four crystal H_2O and eight NH_4~+ cations. It is interesting that there exit GeF_6~(2-) octahedra with high O_h symmetry. Moreover, the GeF_6~(2-) and H_2O connected 3-D grid-shaped network through F…H-O hydrogen bonds. NH_4~+ cations locate in the center of the grids and the electrostatic interactions between NH_4~+ and GeF_6~(2-) further stabilize the supramolecular network.

Key words: GERMANATE, AMMONIUM COMPOUND, FLUORINE COMPOUNDS, CRYSTAL STRUCTURE, SUPERMOLECULAR STRUCTURE, HYDROFLUORIC ACID, PYRIDINE

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