Towards the Design and Synthesis of Organic Cage Rotaxanes

机械互锁分子，如轮烷、链烷和结，已被广泛研究多年。在这些分子中，轮烷是最常见的一种——它们由一个大环组成，其中包括一个哑铃形状的轴，它们通过机械键连接在一起。这允许以旋转（自旋）和平移（穿梭）运动的形式相对自由地移动单个组件。它们的流行导致了功能材料的设计和合成，如笼型轮烷、轮烷链烷、聚轮烷和轮烷树状大分子。在这些材料中，很少有人利用笼（多孔和非多孔）作为轮烷的核心构建块。相比之下，对多孔有机笼的研究发现了几种链链笼结构，通常是由预先形成的笼的再结晶形成的。多孔有机笼是一种形状持久的微孔结构，通常由两个或多个离散的多主题前体自组装形成，从而形成永久的、可访问的腔体。本项目旨在结合多孔有机笼和轮烷的化学性质，研究[n]轮烷的合成，其中有机笼作为构建块，可以用作轮烷结构的阻挡剂和/或核心单元。将这两种物质结合形成有机笼状轮烷可能会产生具有高级功能的材料，例如增加催化或分子分离的位点数量。

Mechanically interlocked molecules, such as rotaxanes, catenanes, and knots, have been extensively studied for many years. Of these molecules, rotaxanes are one of the most common types - these consist of a macrocycle encompassing a dumbbell-shaped component called the axle, which are held together by a mechanical bond. This allows for the relatively free movement of individual components in the form of rotational (pirouetting) and translational (shuttling) movements. Their popularity has led to the design and synthesis of functional materials such as cage-based rotaxanes, rotacatenanes, polyrotaxanes, and rotaxane dendrimers. Of these materials, very little has been done to exploit the use of cages, both porous and non-porous, as core building blocks in rotaxanes. In contrast, studies on porous organic cages have led to the discovery of several catenated cage structures, commonly formed by the recrystallisation of pre-formed cages. Porous organic cages are shape-persistent, microporous structures that typically form from the self-assembly of two or more discrete multi-topic precursors, resulting in the formation of a permanent, guest-accessible cavity. This project aims to combine the chemistry of porous organic cages and rotaxanes by investigating the synthesis of [n]rotaxanes involving organic cages as building blocks, which would either be used as stoppers and/or core units in the rotaxane structure. The combination of these two species to form organic cage rotaxanes could lead to materials with advanced functionality, such as an increase in the number of sites for catalysis or separation of molecules.