Self-Assembly And Applications Of Pillar[n]Arenes In Water

Macrocycles are a type of important compounds in supramolecular chemistry. The discovery of new macrocyclic hosts with fascinating structures and properties can accelerate the development of supramolecular chemistry and provide new opportunities for materials science. The macrocycles discovered in the early years, such as crown ethers, cyclodextrins, calixarenes and cucurbiturils, have been investigated in a variety of areas, including molecular recognition, nanotechnology, fluorescent chemosensors, drug delivery systems and supramolecular polymers. In recent years, pillararenes, a new type of macrocycles, have been widely studied in supramolecular chemistry. In this dissertation, we focus on the self-assemly of pillararenes in water, and investigate the applications of the resultant assemblies.In the first part, we utilized four different types of water-soluble pillar[n]arenes (including a pillar[5]arene with ten carboxylate anions, a pillar [6] arene with twelve carboxylate anions, a pillar[5]arene with ten imidazolium cations, a pillar[6]arene with twelve imidazolium cations) to prepare metal nanoparticles (such as gold nanoparticles and silver nanoparticles). Due to the pillar[n]arenes on the surfaces of nanoparticles which show complexing capacity with guests, we can utilize this ptoperty to control the reverible self-assembly behavior of these nanoparticles in water.In the second part, we synthesized the first amphiphilic pillar[5] arene which can self-assemble into vesicles and then microtubes in water. Due to the amino groups on this amphiphilic pillar[5] arene can be acidized, these vesicles can transform into micelles when the pH of the system decreased. This amphiphilic pillar[5]arene can also be used in the preparation of gold nanoparticles which can further self-assemble into hybrid microtubes. These hybrid microtubes can be reused as a catalyst20times. Then we synthesized five other amphiphilic pillar[5]arenes with different hydrophilic and hydropholic groups to investigate the relationship between the structure and the self-assembly morphology.In the third part, we used water-soluble pillar[n]arenes (a pillar[5]arene with ten carboxylate anions, a pillar[6]arene with twelve carboxylate anions, a pillar[6]arene with twelve imidazolium cations) and guests to construct supramolecular amphiphiles. Due to the reverisible noncovalent interactions between the pillar[n]arenes and guests, these supramolecular amphiphiles can self-assemble in water reversibly. By combining the water-soluble pillar[n]arene stabilized nanoparticles and guests, we constructed hybrid supramolecular amphiphiles. The hybrid supramolecular amphiphiles can self-assemble into hybrid aggregates with various morphologies including micelles, vesicles, and disks with application in near IR controlled release.