Dynamic metallo-supramolecular oligomers stabilized by Cucurbit[8]uril connectors: self-assembly applied to combinatorial chemistry

在美国国家科学基金会化学部大分子、超分子和纳米化学（MSN）项目的支持下，Masson教授研究了水溶性金属配体配合物对CB[n]的识别特性，并开发了动态组合方法来制备动态低聚物和聚合物。在日常生活中使用的大多数物品中都可以找到合成聚合物。俄亥俄大学的Eric Masson教授特别感兴趣的是，聚合物可以根据水中环境自动调整其组成。他的研究小组研究了一种新型动态聚合物的形成和特性，在这种聚合物中，可互换的构建块与南瓜形状的空心分子环（称为葫芦b[8]）相互连接。该项目在生物化学方面有潜在的应用，因为动态聚合物可以与医学或生物学相关的材料（如蛋白质和细胞）相互作用，并在分析化学方面有潜在的应用，因为聚合物可以用作质量控制和药物检测应用中的传感器。该项目是一个多学科的项目，为本科生和研究生提供从有机合成到生物化学和统计分析等广泛的兴趣和才能的培养。此外，学生们还参与了马森教授为平板电脑设计的有机合成棋盘游戏的升级。本文针对的动态低聚物的构建块是连接到CB[8]结合单元的金属-三吡啶配合物。三吡啶配体在4'位置上带有苯基或萘基，以促进CB[8]环的结合。三联吡啶配体还在4-和4 ' -位置被生物激发的侧链（主要基于氨基酸残基）功能化，用于与CB[8]的外壁相互作用和目标识别。金属配体配合物通过与CB[8]环结合而非共价连接。一旦金属配体/CB[8]低聚物形成，CB[8]的外壁实际上参与了目标识别过程。该项目涉及(1)制备具有各种悬垂基团的金属配体配合物库(如铁(II)-，钌（II)-和铱(III)-三吡啶）；(2)评估了它们对CB[n]s的识别特性，以及它们与CB[n]s外凸面的相互作用；(3)在缺乏和存在生物学相关靶点的情况下，金属配体/CB[8]动态低聚物的制备和表征。

With the support of the Macromolecular, Supramolecular and Nanochemistry (MSN) program of the NSF Division of Chemistry, Prof. Masson investigates the recognition properties of water soluble metal-ligand complexes towards CB[n] and develops dynamic combinatorial approaches to preparing dynamic oligomers and polymers. Synthetic polymers are found in most objects used in everyday life. Polymers that spontaneously adjust their composition depending on their environment in water are of particular interest to Professor Eric Masson at Ohio University. His research group studies the formation and properties of a novel type of dynamic polymers in which the interchangeable building blocks are tied to one another with a pumpkin-shaped, hollow molecular ring called cucurbit[8]uril (CB[8]). The project has potential applications in biochemistry, as the dynamic polymers can interact with medically or biologically relevant materials such as proteins and cells, and in analytical chemistry, as the polymers can be used as sensors in quality control and drug detection applications. This project is multidisciplinary, and provides training to undergraduate and graduate students with a broad range of interests and talents, from organic synthesis, to biochemistry and statistical analysis. In addition, students are involved in the upgrade of an organic synthesis board game created by Professor Masson for computer tablets. The building blocks of the dynamic oligomers targeted herein are metal-terpyridine complexes linked to CB[8]-binding units. The terpyridine ligands bear phenyl or naphthyl groups at the 4'-position to promote binding in the CB[8] ring. The terpyridine ligands are also functionalized with bio-inspired side chains (based mostly on amino acid residues) at the 4- and 4"-positions for interactions with the outer wall of CB[8] and for target recognition. The metal-ligand complexes are connected non-covalently via binding to the CB[8] rings. The outer wall of CB[8] participates de facto in the target recognition process once the metal-ligand/CB[8] oligomers are formed. This project involves (1) the preparation of a library of metal-ligand complexes (such as iron(II)-, ruthenium(II)- and iridium(III)-terpyridine) with a variety of pendent groups; (2) the assessment of their recognition properties towards CB[n]s and the interactions between the pendent groups with the outer convex surface of CB[n]s; and (3) the preparation and characterization of the metal-ligand/CB[8] dynamic oligomers in the absence and presence of biologically relevant targets.