Chen Yanhong, Sun Longhui, Chang Shenzhen, Chen Lijuan, Zhao Junwei
Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering , Henan University , Kaifeng , Henan 475004 , People's Republic of China.
Inorg Chem. 2018 Dec 17;57(24):15079-15092. doi: 10.1021/acs.inorgchem.8b02103. Epub 2018 Nov 27.
Three types of N-heterocyclic aromatic acid decorated 3d-4f heterometallic Keggin-type tungstoantimonates: Na[Ln(HO)][Fe(HO)(pic)(B-β-SbWO)]·26HO [Ln = La (1), Pr (2), Nd (3), Sm (4), Eu (5)], NaH[FeWO(HO)(Hpic) (B-β-SbWO)][Ln(HO)][FeWO(HO)(pic)(Hpic)(B-β-SbWO)]·38HO [Ln = Gd (6), Dy (7)], and NaH{[Ln(HO)][Fe(HO)(Hpic)(pic)(B-β-SbWO)]}·44HO [Ln = Ho (8), Er (9), Hpic = 2-picolinic acid] have been prepared. 1-5 comprise a quadripic-inserted Krebs-type [Fe(HO)(pic)(B-β-SbWO)] moiety supported by two [Ln(HO)] groups on both sides where it can be considered that four pic ligands replace eight aqua ligands located on the original Krebs-type [Fe(HO)(B-β-SbWO)] fragment to form the [Fe(HO)(pic)(B-β-SbWO)] moiety. Remarkably, the quadripic-inserted subunits are further concatenated through the coordination role of the pic ligands to create a 3-D heterometallic framework. In contrast, the molecular units of 6-7 contain two kinds of non-Krebs-type quadripic-inserted [FeWO(HO)(Hpic)(B-β-SbWO)] and {[Ln(HO)][FeWO(HO)(pic)(Hpic)(B-β-SbWO)]} moieties. The molecular units of 8-9 contain two identical quadripic-inserted Krebs-type {[Ln(HO)][Fe(HO)(Hpic)(pic)(B-β-SbWO)]} moieties, and both display a 1-D heterometallic double chain. For all we know, 1-9 stand for the first 3d-4f heterometallic tungstoantimonate hybrids functionalized by pic ligands. Particularly, the solid-state NIR photoluminescence (PL) spectrum in the range of 800-1450 nm of 3 and the solid-state visible PL spectra in the range of 500-750 nm of 4, 5, 7, and 8 at room temperature display the featured fluorescence emission bands stemming from Ln cations. In the PL emission procedures of 5 and 7, energy transfer from [B-β-SbWO] fragments and pic ligands to Ln ions has been observed. Additionally, the correlated color temperatures of 4, 5, 7, and 8 are indexed to 2731, 2020, 4557, and 1685 K, respectively.
三种由 N-杂环芳香酸修饰的 3d-4f 异金属 Keggin 型钨锑酸盐：Na[Ln(HO)][Fe(HO)(pic)(B-β-SbWO)]·26HO [Ln = La (1)，Pr (2)，Nd (3)，Sm (4)，Eu (5)]，NaH[FeWO(HO)(Hpic)(B-β-SbWO)][Ln(HO)][FeWO(HO)(pic)(Hpic)(B-β-SbWO)]·38HO [Ln = Gd (6)，Dy (7)]，以及 NaH{[Ln(HO)][Fe(HO)(Hpic)(pic)(B-β-SbWO)]}·44HO [Ln = Ho (8)，Er (9)，Hpic = 2-吡啶甲酸] 已被制备出来。1-5 包含一个由两侧的两个 [Ln(HO)] 基团支撑的四吡啶插入的克雷布斯型 [Fe(HO)(pic)(B-β-SbWO)] 部分，在此可以认为四个吡啶配体取代了位于原始克雷布斯型 [Fe(HO)(B-β-SbWO)] 片段上的八个水合配体，从而形成 [Fe(HO)(pic)(B-β-SbWO)] 部分。值得注意的是，四吡啶插入的亚基通过吡啶配体的配位作用进一步连接，形成一个三维异金属框架。相比之下，6-7 的分子单元包含两种非克雷布斯型的四吡啶插入的 [FeWO(HO)(Hpic)(B-β-SbWO)] 和 {[Ln(HO)][FeWO(HO)(pic)(Hpic)(B-β-SbWO)]} 部分。8-9 的分子单元包含两个相同的四吡啶插入的克雷布斯型 {[Ln(HO)][Fe(HO)(Hpic)(pic)(B-β-SbWO)]} 部分，并且两者都呈现出一维异金属双链结构。据我们所知，1-9 代表首批由吡啶配体功能化的 3d-4f 异金属钨锑酸盐杂化物。特别地，3 在 800 - 1450 nm 范围内的固态近红外光致发光（PL）光谱以及 4、5、7 和 8 在 500 - 750 nm 范围内的固态可见 PL 光谱在室温下显示出源于 Ln 阳离子的特征荧光发射带。在 5 和 7 的 PL 发射过程中，已观察到从 [B-β-SbWO] 片段和吡啶配体到 Ln 离子的能量转移。此外，4、5、7 和 8 的相关色温分别为 2731、2020、4557 和 1685 K。
