Synthesis And Properties Of Hg²⁺Fluorescence Sensor Based On Diarylethylene-Rhodamine B

Fluorescent sensors have been widely used in environmental chemistry,biochemistry,medical diagnosis and other disciplines due to their advantages such as strong specificity,high sensitivity,and simple and fast operation.Mercury is considered to be one of the most dangerous pollutants in the environment and biosphere due to its highly toxic,persistent and bioaccumulative.Therefore,manyorganisms and natural environments.Among many reported sensors,diarylethylene based fluorescent sensors have attracted much attention due to their multiple fluorescence regulation properties.Diarylethylene is widely studied and recognized as the most promising photochromic material due to its excellent photochromism,thermal stability and fatigue resistance.Therefore,the design and synthesis of diarylethylene derivatives with specific recognition functions,such as ion recognition,acid-base response,and detection of small biological molecules,etc.,is our current research trend.Generally,a novel diarylethylene based fluorescent sensor is constructed by introducing some fluorophores with specific responses into the diarylethylene molecule.Rhodamine B derivatives have excellent photophysical properties,such as a wide emission wavelength,high fluorescence quantum yield,and large extinction coefficient,which make them ideal models for constructing fluorescent sensors.Three new fluorescent sensors responsive to Hg²⁺were designed and synthesized,and the Photochromism of these three new fluorescent sensors and their fluorescent switching properties to ions,acid-base and amino acids were studied.The main contents of the paper include:In chapter 1,the research background of fluorescent chemical sensors is briefly described,the research progress of diarylethene compounds is summarized,and the research overview of rhodamine B derivatives is briefly introduced,thus the subject of this study is proposed.In chapter 2,we designed and synthesized a diarylethylene derivative DTE-1O that responds to both light and metal ion stimulation by linking diarylethylene structure and Rhodamine B hydrazide with triazole group and salicylaldehyde group.The compound has good photochromic properties,and can simultaneously recognize Hg²⁺by colorimetry and fluorescence in tetrahydrofuran.The photochromic and systematically studied.In chapter 3,we linked the diarylethylene structure with rhodamine B hydrazide through the Schiff base reaction to obtain DTE-2O.The compound has excellent photochromic and anti-fatigue properties.It can fluorescently recognize Hg²⁺in dimethyl sulfoxide and colorimetrically recognize Cu²⁺in tetrahydrofuran.The respectively,and applied to construct logic gate circuits.In chapter 4,we synthesized a diarylethylene derivative DTE-3O containing rhodamine B unit by Click reaction.The response properties of the compound to light,acid-base,ion,and amino acid were systematically studied.The experimental results show that the compound has good photochromic properties,and its ultraviolet absorption and fluorescence can be regulated by both light and acid-base.At the same time,DTE-3O can selectively recognize Hg²⁺in dimethyl sulfoxide and lysine in acetonitrile,which can be used as fluorescent sensors for Hg²⁺and lysine.