Construction And Properties Study Of Fluorescent Organometallic Assembly System

Fluorescence is a luminescence phenomenon, which materials are excited by light with a certain wavelength, then immediately back to the ground state with the emission of the light. In recent years, Supramolecular organometallic macrocycles and cages with the photophysical properties have aroused extensive attention of the scientists. The assembly system can be applied to detection of metal ions, anions, small molecule; simulating complex photophysical processes of nature and fabrication of photodiode. Tetraphenylethylene is a kind of new type of fluorescent molecules, which has the unusual luminescence behavior. It hasn’t show the emission in solution state but occur fluorescent in the aggregation state, which makes it having a broad application prospect in sensors, biological imaging, photoelectric material and so on.This thesis mainly studies how to use functional bulding blocks to construct a series of supramolecular systems by coordination-oriented driven self-assembly strategy and research on their aggregation behavior and luminescent properties. Including the following three aspects:1. construction of tetraphenylethylene functionalized supramolecular organometallic macrocycles and properties study of macrocycles’ aggregation induced emission; 2. construction of tetraphenylethylene modified supramolecular metallogels based platinum acetylide and platinum nitrogen bond; 3. construction of supramolecular organometallic macrocycles with tunable light emission.The contents and results are as follows:The chapter one. A briefly review about the history of supramolecular chemistry and self-assembly, while coordination-driven self-assembly strategy for the construction of a series of supramolecular assembly system was described mainly; a briefly account about the concept of aggregation induced emission and its application in supramolecular chemistry; a briefly account about supramolecular organometallic gels, especially gels based on alkynylplatinum.The chapter two. A series of tetraphenylethylene modified 120° ligands with aggregation induced emission properties have been designed and synthesized. A class of supramolecular organometallic macrocycles have been constructed by coordination driven self assembly strategy. The structure were characterized by 1H NMR,13C NMR, MS,31PNMR and IR. Spectral study found that compared with macrocycles based on ether bond, macrocycles based on acetylenic bond have better aggregation induced emission properties; Compared with [2+2] and [6+6] macrocycles, [3+3] hexagonal macrocycles have better aggregation induced emission properties. It is interesting to note that precursor-TPE modified pyridine ligands-in dichloromethane/hexane solvent system ha vent show an AIE propertie; However after assembling into macrocycles, macrocycles have an excellent AIE properties.The chapter three. On the basis of the research based on previous work, luminescence behavior and gelling properties of the tetra substituted tetraphenylethylene alkynylplatinum compound is further studied. We found, compared with compounds which occur wavelength redshift after gelling, the gel has wave length-blue shift. By X-ray diffraction (XRD), concentration of 1H NMR spectra, infrared, fluorescence spectra, variable temperature fluorescence spectra, gelling mechanism and sol-gel phase transition are studied. It was also found that the gel system has stimulate response.The Chapter four. Long chain alkane group and amide modified ligand and acceptor containing platinum and tetraphenylethylene were synthesized, then hexagonal organometallic macrocycle was constructed through the [3+3] coordination driven self-assembly. The molecule can further assemble into multiple stimuli responsive luminous gel.The chapter five. Nine kinds of supramolecular macrocycles were constructed and characterized by 1H NMR, MS,31P NMR. The photophysical properties of macrocyclic ligand and their assembly were respectively studied and compared by fluorescence analyzer, which found that luminescence behavior depend on different substituents and had certain regularity. This rule have been verified by the pH titration experiment and will be studied by theoretical calculation.The chapter six. ConclusionThe chapter seven. Experiment...