通过限域自组装构筑离散超分子金属组装体系及其性质研究

The construction of novel supramolecular organometallic assemblies has evolved to be one of the most important topics within supramolecular chemistry and materials science. However, the supramolecular organometallic assemblies prepared in homogeneous solution phase suffered some obvious shortcomings such as the instability and unwanted aggregate behavior, which limited the further applications in some cases. In the present project, starting from a series of organic building blocks, a series of well-defined and discrete 2D supramolecular metallacycles and 3D metallic cages could be generated through coordination-driven self-assembly strategy in the confined space. The further investigations will focus on the properties of the enhancement of stability and dispersity of organometallic assemblies, as well as primary exploration on their functions and applications in catalysis. Based on this project, the construction of discrete supramolecular organometallic assemblies through coordination-driven self-assembly in the confined space strategy will be systematically investigated, which could efficiently avoid the instability and easy aggregate problems in homogeneous solution phase. In addition, the characterization methods of complicated and discrete supramolecular organometallic assemblies in the confined space will be developed. More importantly, taking advantage of the unique structures and properties of the targeted supramolecular organometallic assemblies, further exploration of their application in catalysis will be performed.

构筑新型超分子金属组装体已经成为超分子化学及材料科学等领域的重要研究内容之一。然而，目前在自然状态下（均相溶液）制备的超分子金属组装体存在稳定性相对较弱以及容易聚集的缺点，一定程度上限制了超分子金属组装体系的发展和应用。本项目将设计一系列结构不同的有机小分子组装基元，通过限域配位键导向自组装策略制备一系列有序、离散分布在介孔材料空腔的分立超分子金属大环和金属笼，研究该类超分子金属大环和金属笼在稳定性增强和聚集阻止等方面的性质，并初步考察所制备的离散超分子金属组装体在催化等方面的功能和应用。通过该项目研究，系统研究并发展通过限域配位键导向自组装构筑离散超分子金属组装体系的方法和策略，解决分立超分子金属组装体稳定性相对较弱以及容易聚集的关键问题，建立系统性表征复杂离散超分子金属组装体系的方法和手段，并利用所构建的离散超分子金属组装体系在结构及性质方面的优势，初步探索它们在催化方面的功能和应用。

解决超分子金属组装体系的稳定性相对较弱的问题是目前超分子配位自组装研究领域重要且具有挑战的课题之一。通过限域自组装构筑超分子金属组装体系，可以增强所构筑的目标金属组装体系的稳定性，解决传统方法制备的金属组装体系稳定性弱的问题。在该项目中，申请者分别将催化位点引入金属组装体和负载基底，通过限域配位自组装策略高效构筑了可实现一锅法串联反应的双功能化多相催化剂。通过在组装体与基底上分别引入催化活性位点的巧妙设计，实现了双功能多相催化剂的构筑。该方法在明显提高金属有机笼的稳定性的同时，整合了金属有机笼与介孔材料的优点，所获得的双功能催化剂内的催化活性位点具有显著的正交特征，进而提高了其催化活性、选择性和可回收性。此外，申请者还发展了 “配体面具”策略实现超分子组装体的稳定性强化。通过“配体面具”策略构筑了超分子金属笼，与传统方法制备的超分子金属笼相比较，所构筑的目标超分子金属笼的稳定性大大提升。此外，通过构筑结构多样性的超分子金属笼，证明了“配体面具”策略具有良好的普适性。总之，申请者分别发展了限域配位自组装策略和“配体面具”策略，实现了超分子配位组装体的稳定性强化。