Study On Self-assembly Of Metal Nanoclusters Regulated By Isomers And Their Properties

Supramolecular chemistry is based on non-covalent bonding between molecules(hydrogen bonding,hydrophobic interaction,electrostatic force,van der Waals force,metal-coordination and ?-? stacking,etc.)or some special covalent interaction(such as dynamic Covalent bond)chemical process that assembles between molecules.Supramolecular self-assembly is the core part of supramolecular chemistry,which refers to the process of spontaneous aggregation of two or more primitives to form aggregates.Isomers refer to compounds with the same molecular formula and different structures,and the self-assembly systems involved in them have different self-assembly behaviors,that is to say,the self-assembly behavior can be regulated by the isomers.Metal nanoclusters are a new class of nanomaterials,including polyoxometallates and noble metal nanoclusters,etc.The materials formed by their self-assembly often have excellent properties.The high activity and high selectivity of polyoxometallate made it widely used in the field of adsorption,and the fluorescence properties of precious metal nanoclusters made it widely used in ion detection and other fields.In this paper,based on the self-assembly method,isomers are compounded with polyoxometallates or precious metal nanoclusters,and the differences in self-assembly behaviors of isomers when constructing supramolecular assembly structures are studied.The main contents of this paper are as follows:The first chapter is the study of hollow spheres formed by preyssler polyoxometalates P5W30 and m-phenylenediamine and their adsorption properties.The hollow spheres were characterized by TEM,SEM,etc.,and the formation mechanism of the hollow spheres was changed by Ostwald ripening by changing the concentration and incubation time of m-phenylenediamine,and the experimental results showed that o-phenylenediamine and p-phenylenediamine cannot form hollow spheres.The formed hollow spheres have high specific adsorption of methylene blue,which indicates that it may have applications in wastewater treatment.The second chapter introduces the hollow tubes formed by noble metal nanoclusters Ag9-NCs and phthalic acid and their ion detection.The phase behavior and fluorescence intensity changes of three kinds of phthalic acid and Ag9-NCs self-assembly were systematically studied.The results show that phthalic acid can form gel with Ag9-NCs and can make Ag9-NCs with almost no fluorescence greatly enhanced.Fixing the concentration of Ag9-NCs and changing the concentration of phthalic acid can adjusting the formation of hollow tube structure,and the formed hollow tube has an efficient fluorescence quenching effect on Fe3+,indicating that it may have potential applications in ion detection.The third chapter introduces hollow tube structure formed by the noble metal nanoclusters Ag9-NCs and L-tartaric acid and researched their properties.The phase behavior and fluorescence intensity changes of L-tartaric acid,D-tartaric acid and Ag9-NCs self-assembly were systematically studied.The results show that both L-tartaric acid and D-tartaric acid can form precipitate,fix the concentration of Ag9-NCs,change the concentration of L-tartaric acid,Ag9-NCs/L-tartaric acid hollow tube structure can formed and researched their properties.The results show that the fluorescent performance of the hollow tube is highly than pure Ag9-NCs and the fluorescence yield is high,so it has potential applications in ion detection and fluorescent probes.