Stabilization of Tetravalent 4f (Ce), 5d (Hf), or 5f (Th, U) Clusters by the [伪-SiW9O34]10鈥?/sup> Polyoxometalate
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- 作者：Sylvain Duval ; S茅bastien B茅ghin ; Cl茅ment Falaise ; Xavier Trivelli ; Pierre Rabu ; Thierry Loiseau
- 刊名：Inorganic Chemistry
- 出版年：2015
- 出版时间：September 8, 2015
- 年：2015
- 卷：54
- 期：17
- 页码：8271-8280
- 全文大小：465K
- ISSN：1520-510X
文摘
The reaction of Na10[伪-SiW9O34] with tetravalent metallic cations such as 4f ((NH4)2Ce(NO3)6), 5d (HfCl4), or 5f (UCl4 and Th(NO3)4) in a pH 4.7 sodium acetate buffer solution leads to the formation of four sandwich-type polyoxometalates [Ce4(渭3-O)2(SiW9O34)2(CH3COO)2]10鈥?/sup> (1), [U4(渭3-O)2(SiW9O34)2(CH3COO)2]10鈥?/sup> (2), [Th3(渭3-O)(渭2-OH)3(SiW9O34)2]13鈥?/sup> (3), and [Hf3(渭2-OH)3(SiW9O34)2]11鈥?/sup> (4). All four compounds consist of a polynuclear cluster fragment stabilized by two [伪-SiW9O34]10鈥?/sup> polyanions. Compounds 1 and 2 are isostructural with a tetranuclear core (Ce4, U4), while compound 3 presents a trinuclear Th3 core bearing a 渭3-O-centered bridge. It is an unprecedented configuration in the case of the thorium(IV) cluster. Compound 4 also possesses a trinuclear Hf3 core but with the absence of the 渭3-O bridge. The molecules have been characterized by single-crystal X-ray diffraction, 183W and 29Si nuclear magnetic resonance (NMR) spectroscopy, infrared (IR) spectroscopy, thermogravimetric analysis (TGA), and scanning electron microscopy/energy-dispersive X-ray (SEM/EDX) analysis.