Synthesis of [2]Catenanes by Template-Directed Clipping Approach
摘要:
A series of [2]catenanes were efficiently synthesized in high yields by a template-directed clipping approach with the formation of one macrocycle around another macrocycle containing a dialkylammonium recognition site. Their structures were identified by the NMR spectra and ESI mass spectrometry, and their geometries were investigated by the theoretical calculation.
Heterorotaxanes, one class of topological organic structures, have attracted increasing interesting during the past two decades. In general, two types of heterorotaxane structures exist, one in which two or more different macrocycles are threaded onto one dumbbell-shaped molecule and the other where one macrocycle is threaded onto two or more different dumbbell-shaped molecules. In comparison to these
Subsequently, they were used to construct the corresponding [2]rotaxanes by a template-directed clipping approach. Unusually, two unsymmetrical dendritic [2]rotaxanes containing fluorophore (pyrene units) were also obtained; their optical properties, such as UV/vis absorption and fluorescence, were measured. The results indicate that these two rotaxanes possess stronger intermolecular interaction in the solid
for templating catenane formation. Accordingly, they were subjected to dynamic covalent chemistry, resulting in a series of [n]rota[n]catenane structures (n = 2, 3, 4). In this process, the N-hetero crown ethers were installed on ammonium template sites of linear and macrocyclic components all at once by a template-directed clipping reaction. The results showed that these novel building blocks could be
由于拓扑结构的要求及其在分子机器和设备中的潜在应用,构造新型的机械互锁结构已成为当前引起人们极大关注的主题。轮烷和连环烷作为两个基本的拓扑构架,可用于构建融合结构。在目前的研究中,合成了一类新型的铵骨架。结合在分子的线性部分中的铵基团可用于模板化轮烷的形成,而分子的大环部分可用于模板化链烷的模板化。因此,它们经受了动态共价化学作用,产生了一系列[ n ] rota [ n ]环烷结构(n= 2,3,4)。在这个过程中,通过模板定向的限幅反应,将N-杂冠醚一次全部安装在线性和大环组分的铵模板位上。结果表明,这些新颖的构建基块可以高效组装。最后,这项研究为将来的研究奠定了基础,该研究旨在构建具有多个拓扑单元的复杂的集成结构或聚合物。
Photo-responsive [2]catenanes: synthesis and properties
A series of novel [n]rotaxanes based on a tetraphenylethene (TPE) backbone were constructed by a template-directed clipping approach and their structures were well-characterized.
一系列基于四苯乙烯(TPE)骨架的新型[ n ]轮烷通过模板引导的剪接方法构建,并且它们的结构得到了良好的表征。