Construction And Application Of Supramolecular Coordination Complexes Based On Coordination-driven Self-assembly

The main research object of supramolecular chemistry is covalent interaction between molecules,and supramolecular coordination complex is a supramolecular self-assembly structure with predictable and controllable size formed by metal and ligand under the action of coordination drive.Different shape structures can be formed by appropriately changing the angles of components.According to the plane and three-dimensional structure,it is mainly divided into two categories:supramolecular metal rings and supramolecular metal cages.In recent years,supramolecular metal rings are often used to construct functional materials due to their unique construction methods and rich and easy modification.In this emerging field,it is of great value to explore new supramolecular metal ring structures and expand the practical application to promote the basic and applied research of supramolecular science.Based on this,this thesis designed and prepared different platinum-based receptors and different ligand molecules,constructed a series of supramolecular metal rings through metal coordination self-assembly,and explored its potential applications in chemical sensing and tumor phototherapy.The specific research contents of this thesis are as follows:The first part of the work is to construct a fluorescent responsive supramolecular polymer with a metal ring core by combining metal coordination and host-guest interaction.Firstly,the structure and basic optical properties of the designed and synthesized metal rings were characterized by NMR,high resolution time-of-flight mass spectrometry,and fluorescence emission spectroscopy,which proved the occurrence of metal coordination.Subsequently,nuclear magnetic titration was performed using NMR to prove the occurrence of the host-guest interaction,and combined with morphological analysis and rheological testing by scanning electron microscopy,it was verified that the supramolecular polymer had been successfully prepared.Finally,the fluorescence response of the supramolecular polymer to inorganic acid vapor and the organic acid solution was investigated by fluorescence spectra.In the second part,a rhombus ring with Aggregation-induced Emission(AIE)properties as a photosensitizer was prepared by using a metal coordination-driven self-assembly strategy for photodynamic therapy.Similarly,the structure and optical properties were characterized in detail by NMR,high-resolution time-of-flight mass spectrometry,and fluorescence emission spectroscopy to demonstrate the formation of metal rings.Subsequently,to expand its application in tumor phototherapy and study the difference between its effect and that of its precursor small molecules,we coated it with amphiphilic polymer and prepared spherical hydrophilic nanoparticles with appropriate size.Subsequently,to explore its potential in tumor photodynamic therapy,we measured the ability of nanoparticles to produce singlet oxygen in an aqueous solution by light exposure using the active oxygen fluorescence probe method.Finally,the efficiency of endocytosis was investigated by flow cytometry and confocal scanning in cell experiments.At the same time,the biosafety and photodynamic effect of the nanoparticles on tumor cells were verified by MTT and staining of live and dead cells.