Deng Guocheng, Teo Boon K, Zheng Nanfeng
Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory for Physical Chemistry of Solid Surfaces, National & Local Joint Engineering Research Center of Preparation Technology of Nanomaterials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
J Am Chem Soc. 2021 Jul 14;143(27):10214-10220. doi: 10.1021/jacs.1c03251. Epub 2021 Jun 28.
Many metal clusters are intrinsically chiral but are often synthesized as a racemic mixture. By taking chiral Ag(SPh(CF))(PPh)(DMF) () clusters with bulky thiolate ligands as an example, we demonstrate herein an interesting assembly disassembly (ASDS) strategy to obtain the corresponding, optically pure crystals of both homochiral enantiomers, and . The ASDS strategy makes use of two bidentate linkers with different chiral configurations, namely, (1,2,,)-,-bis(pyridin-3-ylmethylene)cyclohexane-1,2-diamine () and the corresponding chiral analogue . For comparison, we also use the racemic mixture of equimolar of and (). Three three-dimensional (3D) Ag-based metal-organic frameworks (MOFs) were characterized by X-ray crystallography to be [Ag(SPh(CF))(PPh)(LR)] (), [Ag(SPh(CF))(PPh)(LS)] (), and [Ag(SPh(CF))(PPh)(LRS)] (), respectively. As expected, the building blocks in or are homochiral or , respectively. In contrast, is achiral and crystallizes with a diamond-like structure containing alternate and clusters. During the assembly process, the racemic clusters were converted to homochiral building blocks, namely, for and for . Subsequently, the chiral linkers were removed from the crystals of and via hydrolysis with water, and from the disassembled solid material and , optically pure enantiomers and were obtained. It is hoped that this simple assembly strategy can be used to construct cluster-based chiral assemblage materials and that the subsequent disassembly protocol can be used to obtain optically pure chiral cluster molecules from as-prepared racemic mixtures.
许多金属簇本质上是手性的，但常常以消旋混合物的形式合成。以带有庞大硫醇盐配体的手性Ag(SPh(CF))(PPh)(DMF)（）簇为例，我们在此展示了一种有趣的组装-拆卸（ASDS）策略，以获得两种纯手性对映体和的相应光学纯晶体。ASDS策略利用了两种具有不同手性构型的双齿连接体，即(1,2,,)-,-双(吡啶-3-基亚甲基)环己烷-1,2-二胺（）及其相应的手性类似物。为了进行比较，我们还使用了等摩尔的和（）的外消旋混合物。通过X射线晶体学对三种三维（3D）银基金属有机框架（MOF）进行了表征，分别为[Ag(SPh(CF))(PPh)(LR)]（）、[Ag(SPh(CF))(PPh)(LS)]（）和[Ag(SPh(CF))(PPh)(LRS)]（）。正如预期的那样，中的结构单元分别是纯手性的或。相比之下，是无手性的，其晶体结构类似于金刚石，包含交替的和簇。在组装过程中，外消旋簇被转化为纯手性结构单元，即对于为，对于为。随后，通过用水水解从和的晶体中去除手性连接体，并从拆卸后的固体材料和中获得光学纯对映体和。希望这种简单的组装策略可用于构建基于簇的手性组装材料，并且后续的拆卸方案可用于从制备的外消旋混合物中获得光学纯的手性簇分子。
