Xiong Jia, Yang Zeng-Xi, Ma Pengtao, Lin Dunmin, Zheng Qiaoji, Huo Yu
College of Chemistry and Materials Science, Sichuan Normal University, Chengdu 610066, People's Republic of China.
Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, People's Republic of China.
Inorg Chem. 2021 May 17;60(10):7519-7526. doi: 10.1021/acs.inorgchem.1c00859. Epub 2021 Apr 23.
Two novel polynuclear dysprosium (Dy)-containing polytungstoarsenates, CsKNa[(AsWO)DyWO(HO)]·40HO () and CsKNa[(AsWO)DyWO(HO)(μ-OH)(OH)]·78HO (), have been synthesized via the reaction of the preformed polyoxometalate (POM) precursor [AsWO(HO)] and Dy ions through controlling pH. The polyanion of can be described as a dimer of two similar trimers {(AsWO)DyWO(HO)} that are linked by Dy cation and two μ-oxo groups, and the Dy(III) ions in are arranged in a linear fashion. Compound presenting an interesting W-shaped structure, assembly composed of a dimeric {(AsWO)WDyO(HO)}, a trimer {(AsWO)WDyO(OH)(HO)}, and a particular sandwiched {(AsWO)WDyO(μ-OH)(HO)} segment concatenated by μ-oxo groups. The solid-state luminescence performances and lifetime decay behaviors of and were systematically researched at ambient temperature, and time-resolved fluorescence spectra of and indicate energy transfer (ET) from the photoexcitation O → M ligand to the metal charge-transfer (LMCT) bands of the POM ligands to Dy ions. Moreover, the dynamic magnetic measurement indicates that and exhibit slow relaxation of the magnetization.
通过控制pH值，利用预先形成的多金属氧酸盐（POM）前体[AsWO(HO)]与Dy离子反应，合成了两种新型的含多核镝（Dy）的聚钨砷酸盐CsKNa[(AsWO)DyWO(HO)]·40HO （）和CsKNa[(AsWO)DyWO(HO)(μ-OH)(OH)]·78HO （）。的聚阴离子可描述为两个相似三聚体{(AsWO)DyWO(HO)}通过Dy阳离子和两个μ-氧基团连接而成的二聚体，中Dy(III)离子呈线性排列。化合物呈现出有趣的W形结构，由二聚体{(AsWO)WDyO(HO)}、三聚体{(AsWO)WDyO(OH)(HO)}和由μ-氧基团连接的特殊夹心{(AsWO)WDyO(μ-OH)(HO)}片段组成。在室温下系统研究了和的固态发光性能和寿命衰减行为，和的时间分辨荧光光谱表明存在从光激发O→M配体到POM配体的金属电荷转移（LMCT）带再到Dy离子的能量转移（ET）。此外，动态磁性测量表明和表现出磁化强度的缓慢弛豫。
