Department of Chemistry, Hallym University, Chuncheon, Gangwon-do 24252, Republic of Korea.
Dalton Trans. 2018 May 15;47(19):6660-6665. doi: 10.1039/c8dt00747k.
A cobalt (Co) supramolecular triple-stranded helicate, [Co8(PDA)6(Br-PTA)3(DMF)4(H2O)2] (1) (PDA = 2,6-pyridinedicarboxylate, Br-PTA = 5-bromoisophthalate, DMF = dimethylformamide), is successfully synthesized and fully characterized. The solid-state structure of 1 shows that four cobalt atoms are coordinated by three PDA ligands to form a tetranuclear cobalt cluster with three extension points and the ditopic Br-PTA ligands interlink two basic assembly units. In crystal packing, the bromo group is surrounded by the cavity-like tetranuclear cobalt cluster, which acts as a metallocavitand, to generate a unique cage-like crystal packing geometry. The isomorphous molecular cage, which exhibits a similar crystal-packing geometry as observed in 1, is also successfully isolated. This is an unusual example of a highly symmetric cage-like crystal packing architecture, resulting from the interaction among metallocavitands of in situ generated supramolecular modules.
一种钴（Co）超分子三重螺旋螺旋体，[Co8(PDA)6(Br-PTA)3(DMF)4(H2O)2]（1）（PDA=2,6-吡啶二甲酸，Br-PTA=5-溴间苯二甲酸，DMF=二甲基甲酰胺），成功合成并进行了全面表征。1 的固态结构表明，四个钴原子被三个 PDA 配体配位，形成具有三个延伸点的四核钴簇，而双功能 Br-PTA 配体连接两个基本组装单元。在晶体堆积中，溴原子被类似笼状的四核钴簇包围，该簇充当金属穴醚，产生独特的笼状晶体堆积几何形状。还成功分离出具有类似晶体堆积几何形状的同构分子笼。这是一个高度对称的笼状晶体堆积结构的不寻常例子，是由原位生成的超分子模块的金属穴醚之间的相互作用产生的。
