Two new extended structures built from condensed Keggin-type polyoxotungstates and copper(II)-organic units
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- 作者：Dongying Du ; Yaqian Lan ; Xinlong Wang ; Kuizhan Shao ; Haining Wang ; Zhongmin Su
- 关键词：Polyoxotungstate ; Keggin dimer ; Supramolecule ; Electrochemical property
- 刊名：Solid State Sciences
- 出版年：2010
- 出版时间：January 2010
- 年：2010
- 卷：12
- 期：1
- 页码：128-133
- 全文大小：993 K
文摘
The reactions between trivacant Keggin polyanions and transition metal ions in the presence of organoamine resulted in the isolation of two new polyoxotungstates, that is, [Hen]2[Cu(en)2(H2O)]2{[Cu(en)2]2[X2W23CuO79]}·4H2O (X = Ge, 1; X = Si, 2; and en = 1,2-ethylenediamine). Single-crystal X-ray diffraction analyses reveal that the polyanions in 1 and 2 are constructed by saturated Keggin anions condensed through sharing common oxygen atoms into Keggin dimers, which are further fused by copper(II) bridging fragments into one-dimensional (1D) ladder-like chains and then extended to a 3D supramolecular framework through hydrogen bond interactions. The IR spectrum and X-ray powder diffraction have been studied in detail for compounds 1 and 2. The UV spectrum, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), the cyclic voltammetry and electrocatalytic activity toward the reduction of nitrite have also been studied for compound 1.