Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, P. R. China.
Dalton Trans. 2019 Sep 17;48(36):13850-13857. doi: 10.1039/c9dt02710f.
Three [α2-P2W17O61]10--based lanthanide-containing polyoxometalates (LCPs) [N(CH3)4]3H8{Ln(H2O)7[Ln(H2O)3Ln(H2O)4(α2-P2W17O61)2]}·48H2O [Ln = La3+ (1), Ce3+ (2), and Pr3+ (3)] were successfully obtained by the reaction of a trivacant Dawson-type precursor [P2W15O56]12- and lanthanide ions under hydrothermal conditions. The compounds 1-3 were fully characterized by single-crystal X-ray diffraction and a series of analytical methods, including elemental analyses, powder X-ray diffraction (PXRD), IR spectroscopy, Raman spectroscopy, UV/vis diffuse reflectance spectroscopy, and thermogravimetric analysis (TGA). Single-crystal X-ray diffraction analyses indicated that 1-3 were isostructural and exhibited a 2D network architecture through the alternative connection of [α2-P2W17O61]10- and lanthanide ions. The photoluminescence properties of 1-3 were investigated at room temperature, and 3 displayed the characteristic emissions of a Pr3+ emitting center, indicating that POMs can transfer energy and sensitize Pr3+ emissions. The reason for the weak emission intensity of Pr3+ emitting ions was because the radiationless losses via a charge-transfer Pr → W state negatively affected the emission of the Pr3+ ions in LCPs.
三种基于[α2-P2W17O61]10-的含镧系元素的多金属氧酸盐（LCP）[N(CH3)4]3H8{Ln(H2O)7[Ln(H2O)3Ln(H2O)4(α2-P2W17O61)2]}·48H2O [Ln = La3+ (1), Ce3+ (2), 和 Pr3+ (3)] 是通过在水热条件下使用空缺的 Dawson 型前驱体[P2W15O56]12-和镧系元素离子反应得到的。化合物 1-3 通过单晶 X 射线衍射和一系列分析方法（包括元素分析、粉末 X 射线衍射 (PXRD)、红外光谱、拉曼光谱、紫外/可见漫反射光谱和热重分析 (TGA)）进行了充分的表征。单晶 X 射线衍射分析表明 1-3 是同构的，并通过[α2-P2W17O61]10-和镧系元素离子的交替连接呈现出二维网络结构。1-3 的光致发光性质在室温下进行了研究，3 显示出 Pr3+ 发射中心的特征发射，表明 POM 可以传递能量并敏化 Pr3+ 的发射。Pr3+ 发射离子的发射强度较弱的原因是通过电荷转移 Pr → W 态的无辐射损耗对 LCP 中 Pr3+ 离子的发射产生负面影响。
