Rare-earth organic frameworks involving three types of architecture tuned by the lanthanide contraction effect: hydrothermal syntheses, structures and luminescence
Rare-earth organic frameworks involving three types of architecture tuned by the lanthanide contraction effect: hydrothermal syntheses, structures and luminescence
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DOI：
10.1039/c0dt00031k
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发表时间：
2010-01-01
影响因子：
4
通讯作者：
Gao, Shan
中科院分区：
文献类型：
--
作者：
Deng, Zhao-Peng;Kang, Wei;Gao, Shan
在水热条件下合成了第一例含3-氨基吡嗪-2-羧酸（Hapca）的稀土有机骨架化合物，并通过元素分析、IR、PL、TG、粉末和单晶X射线衍射对其进行了表征。这十种配合物表现出三种不同的结构类型，镧系元素半径逐渐减小：[La（apca）（3）]（n）（1）对于I型，{[Ln（apca）（ox）（H（2）O）（2）]中心点H（2）O} n（Ln = Pr（2），Nd（3），ox =草酸盐）;（Ln（2）（apca）（4）（OH）（2）（H（2）O）（2）]（n）（Ln = Sm（4），Eu（5），Gd（6），Tb（7），Dy（8），Er（9），Y（10））。I型结构由沿沿着a轴的一维“雪花”链组成，其进一步通过氢键互连以产生包含无限（-C-O-La-）（n）棒状SBU的三维sra网拓扑结构。Ⅱ型为二维Ln-apca-ox 4（4）-网络，由配位水分子和自由水分子组成平面的水四聚体（H（2）O）（4）。III型还包括由Ln-apca-OH构建的2D 4（4）层网络。结构的多样性主要是由配位体的变化和镧系收缩效应引起的。值得注意的是，II型草酸盐是由3-氨基吡嗪-2-羧酸通过氧化-水解反应原位合成的。配合物1具有较强的蓝色荧光，配合物5具有Eu（3+）的特征荧光。
The first example of rare-earth organic frameworks with 3-aminopyrazine-2-carboxylic acid (Hapca) was synthesized under hydrothermal conditions and characterized by elemental analysis, IR, PL, TG, powder and single-crystal X-ray diffraction. These ten complexes exhibit three different structure types with decreasing lanthanide radii: [La(apca)(3)](n) (1) for type I, {[Ln(apca)(ox)(H(2)O)(2)]center dot H(2)O} n (Ln = Pr (2), Nd (3), ox = oxalate) for type II, and [Ln(2)(apca)(4)(OH)(2)(H(2)O)(2)](n) (Ln = Sm (4), Eu (5), Gd (6), Tb (7), Dy (8), Er (9), Y (10)) for type III. The structure of type I consists of 1D "snowflake" chains along a-axis, which are further interconnected by hydrogen bonds to produce a 3D sra net topology containing infinite (-C-O-La-)(n) rod-shaped SBU. Type II has 2D Ln-apca-ox 4(4)-net, in which a planar udud water tetramers (H(2)O)(4) are formed by coordinated and free water molecules. Type III also comprises of 2D 4(4)-layer network constructed from Ln-apca-OH. The structure diversity is mainly caused by the variation of coordinated ligand and lanthanide contraction effect. Remarkably, the oxalate in type II was in situ synthesized from 3-aminopyrazine-2-carboxylic acid through an oxidation-hydrolysis reaction. The luminescent investigations reveal that complex 1 exhibits strong blue emission and complex 5 exhibits characteristic luminescence of Eu(3+).