One-pot synthesis and structural characterization of a Tb(III) coordination polymer based on a tripodal Schiff base ligand adopting an exo-bridging coordination mode
One-pot synthesis and structural characterization of a Tb(III) coordination polymer based on a tripodal Schiff base ligand adopting an exo-bridging coordination mode
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DOI：
10.1016/j.poly.2014.08.033
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发表时间：
2015-01-08
期刊：
影响因子：
2.6
通讯作者：
Iki, Nobuhiko
中科院分区：
文献类型：
--
作者：
Masuya, Atsuko;Igarashi, Chikai;Iki, Nobuhiko
利用柔性三足希夫碱配体三[2-(水杨基氨基)乙基]胺(H3L)衍生物，通过一锅反应合成了一种新型Tb(III)配位聚合物和离散配合物。 5-甲基水杨醛 (5-MeSal) 与三(2-氨基乙基)胺 (tren) 在 Tb(CF3SO3)(3) 存在下以 3:2:1 (=5-MeSaktren:Tb(III)) 摩尔比缩合得到 (TbL)-L-1，去质子化的配体以内配位方式将 Tb(III) 封装在其 N4O3 空腔中。在这里，过量的tren充当解离配体质子的碱。将tren 的量减少到3:1:1 的比例得到[Tb((H3L)-L-1)(2)](CF3SO3)(3)。水。在该化合物中，Tb(III)中心由两个(H3L)-L-1配体采用外封端模式配位，在(H3L)-L-1空腔外提供三个O原子。在上述反应中用 Tb(NO3)3 代替 Tb(CF3SO3)(3) 引起配位聚合物 [Tb((H3L)-L-1)(NO3)(3)DMF.1/6H(2)O](n) 的显着结构变化。在该聚合物中，配体采用了前所未有的外桥配位模式，这是在这种三足希夫碱配体中观察到的第一个桥联模式。外桥配体的三个芳环通过CH中心点中心点中心点pi相互作用彼此靠近，每个O原子与三个不同的Tb(III)离子配位以构建三维聚合物连接。 3D框架具有纳米孔结构，其内壁由交替出现的亲水性和疏水性区域组成。本研究表明，三足希夫碱配体可以作为一类新型的柔性结构单元来构建 Ln(III) 配位聚合物。 (C) 2014 年，爱思唯尔有限公司出版。
A novel Tb(III) coordination polymer and discrete complexes have been synthesized by one-pot reaction utilising flexible tripodal Schiff base ligands, tris[2-(salicylideneamino)ethyl]amine (H3L) derivatives. Condensation of 5-methylsalicylaldehyde (5-MeSal) with tris(2-aminoethyl)amine (tren) in the presence of Tb(CF3SO3)(3) in a 3:2:1 (=5-MeSaktren:Tb(III)) molar ratio gives (TbL)-L-1, and the deprotonated ligand encapsulates the Tb(III) in its N4O3 cavity in endo-coordination. Here, the excess tren acts as a base to dissociate the proton of the ligand. Decreasing the amount of tren to a 3:1:1 ratio gives [Tb((H3L)-L-1)(2)](CF3SO3)(3). H2O. In this compound, the Tb(III) centre is coordinated by two (H3L)-L-1 ligands adopting the exo-capping mode to provide three O atoms outside the cavity of (H3L)-L-1. Replacing Tb(CF3SO3)(3) with Tb(NO3)3 in the above reaction induced a substantial structural change to coordination polymer [Tb((H3L)-L-1)(NO3)(3)DMF.1/6H(2)O](n). In this polymer, the ligand adopts an unprecedented exo-bridging coordination mode, which is the first bridging mode observed for this tripodal Schiff base ligands. Three aromatic rings of the exo-bridging ligand are close to each other by CH center dot center dot center dot pi interactions and each O atom coordinates to three different Tb(III) ions to construct a three-dimensional polymeric connection. The 3D framework has the nano-pore structure with inner walls that consisted of alternately appearing hydrophilic and hydrophobic regions. The present study shows that the tripodal Schiff base ligand can be a novel class of flexible building block to construct the Ln(III) coordination polymer. (C) 2014 Published by Elsevier Ltd.