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Abstract

This thesis describes the synthesis of interlocked giant [8+12] organic cages and the systematic investigations of the catenation mechanism. By tuning the substituents of the building blocks and the length of linkers, a series of monomeric cages with different volumes and structures were designed and synthesized. Based on these monomeric cages, four major factors in the catenation process were studied: 1. The effects of the size and cavity volume of the monomeric cage on catenation tendency (Chapter 3.1). Three types of triptycene triamine and two dialdehyde linkers were utilized to construct six catenanes and two organic cages. By investigating the relationship between the formation of catenanes and the size of monomeric cages, it was found, when the difference between the volume of the cage and its cavity is smaller, the monomeric cages tend to be interlocked more. 2. The structural effects on catenation (Chapter 3.2). To further figure out the driving force of catenation, several dialdehyde linkers with varied substituents were used to build monomeric cages. Experimental results showed that the structural changes of the monomeric cages significantly influenced the catenation results. 3. Solvent effects (Chapter 3.3). To explore the solvent effects on the catenation, a solvent screening was conducted for the synthesis of catenanes. Moreover, the solvent mixtures and several corresponding combinations were also investigated. 4. Synthesis of polycatenanes (Chapter 3.4). According to the studies of solvents and structural effects in previous chapters, the rational synthesis and isolation of dimer, trimer, and tetramer could be achieved by adjusting the ratio of solvent mixtures, type of building blocks, and the equivalents of linkers. In addition, an ongoing project about obtaining single crystals of metal-assisted covalent organic frameworks (MSOFs) was shown in Chapter 4. The idea is to prepare the metal-organic frameworks (MOFs) single crystals first and then transform them into MSOFs single crystals by post-modification. Two approaches were designed and the corresponding MOFs were synthesized, unfortunately, only nanocrystals of MOFs were obtained currently.