Synthesis And Properties Of Cu²⁺、Al³⁺、Zn²⁺ And CN^- Chemosensor Based On Diarylethene With Nitrogen/Oxygen Groups

Because of the continuous development of today’s social,more and more ions are inadvertently poured into the natural environment,which has a major impact on people’s health and lifestyle.Therefore,the detection of ions in the environment and biological organisms remains an important area of research.Compared with traditional detection methods（such as ion selective electrode method,voltammetry,atomic absorption spectroscopy）,fluorescence sensors are widely used due to their simple operation,high sensitivity,good selectivity and fast response time.Among the reported fluorescence sensors,fluorescence sensors based on diarylene molecules have significant fatigue resistance,excellent thermal stability and multiple-response light switchability have become hot topics of research.As an essential trace of heavy metal elements and essential nutrients in the organism,Cu²⁺plays an important role in various basic physiological processes.Aluminum is the third richest（about 8%by weight）element in the earth’s crust and is found in most animal and plant tissues as well as in natural water.Apart from aluminum,zinc is the second most abundant transition metal ion in organisms and plays an integral role in human health.It can affect many organ systems such as the gastrointestinal tract,central nervous system and reproductive system.And because CN^-is extremely toxic to living things and the environment,it has received extensive attention and research.Therefore,it is very important to design a series of high-sensitivity and high-sensitivity fluorescence sensors for detecting Cu²⁺,Al³⁺and Zn²⁺and anion CN^-.Compared with the fluorescent chemical sensors with single response to the above ions,it is more practical to design and synthesize a diarylene fluorescence sensor with multiple responses.Based on this,four nitrogen/oxygen-containing diarylene compounds were designed and synthesized,and the photochromic properties of these compounds and their selectivity to anion and cation were systematically studied.The main research contents of the thesis are as follows:In chapter 1,the research progress of diarylene compounds,the basic properties and applications of diarylene compounds,the research progress of fluorescent chemical sensors and the research progress of Cu²⁺,Al³⁺,Zn²⁺and CN^-chemsensors based on diarylene molecules are introduced.Finally,the research content of this topic is put forward.In chapter 2,a novel diphenylene compound DT-1O containing a benzoxazole group was designed and synthesized,and its properties were systematically tested and studied in depth.The compound DT-1O exhibits good photochromic properties and fluorescent switching properties in aqueous acetonitrile,and compound DT-1O can specifically detect Cu²⁺.DT-1O can also identify acid and base in UV channel.In chapter 3,a diphenylene compound DT-2O containing a phenylpyrazole group was designed and synthesized,and its properties were systematically tested and studied in depth.DT-2O exhibits good photochromism and fatigue resistance in chromatographic methanol solution.In addition,DT-2O can selectively identify Al³⁺and Zn²⁺,and further determine the complexation sites and modes of DT-2O and Al³⁺and Zn²⁺by means of nuclear magnetic resonance and mass spectrometry.In chapter 4,two diphenylene compounds DT-3O and DT-4O containing benzofurancarboxamide groups were designed and synthesized.DT-3O and DT-4O both exhibited good photochromic properties.In the initial state,DT-3O and DT-4O are colorless.DT-3O was blue after ultraviolet light irradiation,while DT-4O was purple,and they all recognized Zn²⁺and CN^-with high selectivity.The properties of DT-4O were systematically tested and studied in depth.The complexation sites and methods of DT-4O and Zn²⁺were further determined by methods such as nuclear magnetic resonance and mass spectrometry.