上海交通大学刘燕团队报道了具有多种顶点的同手性多孔金属有机多面体。相关研究成果于2023年1月17日发表于国际顶尖学术期刊《美国化学会杂志》。

以非阿基米德/柏拉图体系结构为特征的具有多种顶点的金属有机多面体因其迷人的结构和特性而引起了极大的关注，但实现起来仍然具有挑战性。

该文中，研究人员报告了一种组合策略，通过将动力学不稳定的金属离子与非平面有机连接体结合，而不是通常的仅惰性金属中心和平面配体，来制造这种非经典多面体笼。这有助于合成能够结合Ni（II）离子以产生具有两个混合金属/有机顶点的规则凸笼Ni6L8和具有三个或四个混合顶点的三个很少报道的凹笼Ni14L8、Ni18L12和Ni24L16的对映纯扭曲四（3-吡啶基）基TADDOL（TADDOL=四芳基-1,3-二氧戊环-4,5-二甲基）配体（L）。每个笼子都有一个用手性二羟基官能团修饰的两亲性空腔，并包装成三维结构。笼的对映选择性吸附和分离性能强烈依赖于它们的孔结构特征。

特别地，具有宽开口的Ni14L8和Ni18L12可以是用于吸附和固相萃取分离多种外消旋螺二醇的固体吸附剂，具有高达98%的ee，而具有较小孔径的Ni6L8和Ni24L16不能吸附外消旋体。综合主客体加合物的单晶X射线衍射分析和GCMC模拟表明，对映体特异性识别能力来源于有序的手性内球体以及手性微环境中的多重相互作用。

该项工作为多面体笼的合理设计提供了一种有吸引力的策略，显示出与经典组件不同的几何上迷人的结构。

附：英文原文

Title: Homochiral Porous Metal–Organic Polyhedra with Multiple Kinds of Vertices

Author: Xianhui Tang, Chunlong Meng, Nakul Rampal, Aurelia Li, Xu Chen, Wei Gong, Hong Jiang, David Fairen-Jimenez, Yong Cui, Yan Liu

Issue&Volume: January 17, 2023

Abstract: Metal–organic polyhedra featuring non-Archimedean/Platonic architectures with multiple kinds of vertices have aroused great attention for their fascinating structures and properties but are yet challenging to achieve. Here, we report a combinatorial strategy to make such nonclassic polyhedral cages by combining kinetically labile metal ions with non-planar organic linkers instead of the usual only inert metal centers and planar ligands. This facilitates the synthesis of an enantiopure twisted tetra(3-pyridyl)-based TADDOL (TADDOL = tetraaryl-1,3-dioxolane-4,5-dimethanol) ligand (L) capable of binding Ni(II) ions to produce a regular convex cage, Ni6L8, with two mixed metal/organic vertices and three rarely reported concave cages Ni14L8, Ni18L12, and Ni24L16 with three or four mixed vertices. Each of the cages has an amphiphilic cavity decorated with chiral dihydroxyl functionalities and packs into a three-dimensional structure. The enantioselective adsorption and separation performances of the cages are strongly dependent on their pore structure features. Particularly, Ni14L8 and Ni18L12 with wide openings can be solid adsorbents for the adsorptive and solid-phase extractive separation of a variety of racemic spirodiols with up to 98% ee, whereas Ni6L8 and Ni24L16 with smaller pore apertures cannot adsorb the racemates. The combination of single-crystal X-ray diffraction analysis of the host–guest adduct and GCMC simulation indicates that the enantiospecific recognition capabilities originate from the well-organized chiral inner sphere as well as multiple interactions within the chiral microenvironment. This work therefore provides an attractive strategy for the rational design of polyhedral cages, showing geometrically fascinating structures with properties different from those of classic assemblies.

DOI: 10.1021/jacs.2c12424

Source: https://pubs.acs.org/doi/10.1021/jacs.2c12424