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合成了 3 种新的多金属氧酸盐 (CTMA)5BW12O40·8H2O, (CTMA)4SiW12O40·3H2O, (CTMA)3PW12O40·2H2O,利用元素分析、IR 光谱和 TG-DTA 技术对其进行了表征。IR 光谱表明这些化合物不仅含有 Keggin 型结构,而且存在有机大阳离子的特征吸收峰;TG-DTA 曲线显示它们的热行为是一个多步分解过程,首先这些化合物在大约 269℃以下脱去水分子,然后它们的无水多金属氧酸盐经历了两步或 3 步的分解过程,分别脱去 CTMA 分子及其碎片,并伴随 Keggin 型结构的塌陷。通过 XRD 和 IR 光谱确证其最终分解产物是一个含有 WO3与 B2O3, SiO2或 P2O5的混合物。同时还提出了这些化合物可能的热分解过程。
Three novel polyoxometalates (CTMA) 5BW12O40 · 8H2O, (CTMA) 4SiW12O40 · 3H2O, (CTMA) 3PW12O40 · 2H2O were synthesized and characterized by elemental analysis, IR and TG-DTA techniques. IR spectra indicate that these compounds not only contain Keggin structure but also have characteristic absorption peaks of organic large cations. The TG-DTA curves show that their thermal behavior is a multi-step decomposition process. Firstly, these compounds take off water molecules at about 269 ℃, Then their anhydrous polyoxometallates undergo a two- or three-step decomposition process, detaching the CTMA molecules and their fragments, respectively, with the collapse of the Keggin-type structure. It was confirmed by XRD and IR spectroscopy that the final decomposition product was a mixture containing WO3 and B2O3, SiO2 or P2O5. The possible thermal decomposition of these compounds is also proposed.