华东师范大学学报(自然科学版) ›› 2008, Vol. 2008 ›› Issue (4): 78-87.

• 化学化工 • 上一篇    下一篇

Dawson结构多金属含氧酸盐热解性质研究(英)

孔爱国, 李疆, 赖克强, 张贵荣, 丁旵明, 单永奎   

  1. 华东师范大学 化学系，上海200062
  • 收稿日期:2007-04-01 修回日期:2007-06-05 出版日期:2008-07-25 发布日期:2008-07-25
  • 通讯作者: 单永奎

Thermal decomposition behavior of metal-oxygen clusters with Dawson structure(English)

KONG Ai-guo, LI Jiang, LAI Ke-qiang, ZHANG Gui-rong, DING Han-ming, SHAN Yong-kui   

  1. Department of Chemistry, East China Normal University, Shanghai200062, China
  • Received:2007-04-01 Revised:2007-06-05 Online:2008-07-25 Published:2008-07-25
  • Contact: SHAN Yong-kui

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摘要： 用变温XRD，变温IR以及TG-DTA等方法，系统地研究了具有Dawson结构的YmHnP2M18O62•qH2O（Y=K+, NH4+, Cu2+；M=Mo，W）的热解性质，获得了它们较为精确的热分解温度，对其热分解的判断方法提出了一些新的见解.结果表明，以钼为配位原子的Dawson结构钾盐，铵盐，铜盐分别在250 ℃, 210 ℃, 240 ℃ 发生了热重排，生成了具有Keggin结构的化合物.以钨为配位原子的钾盐在410 ℃也有相似的行为，但铵盐和铜盐却没有观察到类似的热重排现象，分别在400 ℃, 450 ℃直接热分解为WO3.这些结果显示，热重排现象的发生可能与相应的Keggin结构化合物的热稳定性有关.

关键词: Dawson结构, 多金属含氧酸盐, 热解, Dawson结构, 多金属含氧酸盐, 热解

Abstract: The thermal decomposition behavior of metal-oxygen clusters with Dawson structure, YmHnP2M18O62•qH2O, was systematically investigated using the X-ray power thermodiffractometry and FTIR at different temperatures, TG-DTA. The experimental results indicated that Dawson-type metal-oxygen clusters with anion,[P2Mo18O62]6-,and different counter cations,NH4+,Cu2+,K+,underwent an irreversible thermal rearrangement around 210 ℃,240 ℃,250 ℃, respectively to give the corresponding Keggin-type metal-oxygen clusters containing [PMo12O40]3-as one of the products. For the metal-oxygen clusters containing tungsten, the pyrolysis procedure of potassium salt with [P2W18O62]6-anion is similar to that of metal-oxygen clusters with [P2Mo18O62]6-anion, whenas the NH4+, Cu2+salts of [P2W18O62]6-seem to decompose directly into WO3 at 400 ℃, 450 ℃,respectively.These results testify that the thermal solid-state rearrangements of Dawson-type anions correlated with the thermal stability of the corresponding Keggin-type compounds. Furthermore, some proposals about the criterion and the adjudication of thermal decomposition temperature for metal-oxygen clusters with different thermal decomposition behavior are also given.

Key words: metal-oxygen clusters, thermal decomposition, Dawson structure, metal-oxygen clusters, thermal decomposition

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