Construction of tetrahedral chiral-at-metal complexes towards asymmetric light-driven redox catalysis

构建四面体手性金属配合物以实现不对称光驱动氧化还原催化

基本信息

批准号：
22KJ0852
负责人：
LIU Yuanfei
金额：
$ 1.09万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for JSPS Fellows
财政年份：
2023
资助国家：
日本
起止时间：
2023-03-08 至 2024-03-31
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-22KJ0852/
关键词：
nickel cobalt chiral-at-metal tetrahedral geometry redox-active spontaneous resolution

项目摘要

In one year research, I mainly focus on construction and resolution of redox-active chiral-at-nickel(II) and chiral-at-cobalt(II) complexes.First, I constructed two tetrahedral chiral-at-nickel(II) complexes using an unsymmetrical, achiral tridentate ligand and characterized them by NMR, ESI-MS, single-crystal XRD and UV-vis absorption spectroscopy. The structural information was carefully elucidated. The complexes adopt a tetrahedral geometry and exhibit redox activity as well as visible-light absorption. Also, they are capable of ligand exchange for substrate activation.Second, I succeeded in spontaneous resolution of S/R-[NiL(ClLi(thf)2)] complex to conglomerate crystals at low temperature. I optimized the crystallization conditions and elucidated the crystallographic structure. I found that hydrogen bondings are essential to achieve spontaneous resolution. Starting from achiral building blocks, the ligands and nickel ions assemble chiral-at-metal complexes, 1D chiral helices, 3D chiral suprastructure and finally homochiral crystals in a highly asymmetric manner. This is related to the origin of homochirality in biological systems in ancient earth and sheds light on the concept of crystal engineering.I also successfully constructed a tetrahedral chiral-at-cobalt(II) complex and charactered it by NMR, ESI-MS, single-crystal XRD, UV-vis absorption spectroscopy. Together with silver salts, the complex was found to be capable for carbon-carbon bond cleavage of 1,2-diarylethylenediamine. The reaction condition is under optimization currently.

在一年的研究中，我主要致力于氧化还原活性手性镍(II)和手性钴(II)配合物的构建和拆分。首先，我构建了两个四面体手性镍(II)配合物使用不对称的非手性三齿配体，并通过 NMR、ESI-MS、单晶 XRD 和紫外-可见吸收光谱对其进行表征。结构信息被仔细阐明。该配合物采用四面体几何形状，表现出氧化还原活性以及可见光吸收。此外，它们还能够进行配体交换以激活底物。其次，我成功地在低温下将S/R-[NiL(ClLi(thf)2)]络合物自发拆分为聚集晶体。我优化了结晶条件并阐明了晶体结构。我发现氢键对于实现自发拆分至关重要。从非手性构件开始，配体和镍离子以高度不对称的方式组装手性金属配合物、1D手性螺旋、3D手性超结构，最后组装成纯手性晶体。这与古代地球生物系统中同手性的起源有关，并为晶体工程的概念提供了线索。我还成功构建了四面体手性钴(II)配合物，并通过NMR、ESI-MS、单手性对其进行了表征。 -晶体X射线衍射、紫外-可见吸收光谱。发现该配合物与银盐一起能够裂解 1,2-二芳基乙二胺的碳-碳键。目前反应条件正在优化中。