The Synthesis Of Schiff Base Fluorescent Probe Based On Spirobifluorene As The Parent And Its Application In Metal Ion Detection

With the increasing development of science and technology,metals and their compounds play an increasingly important role in human social production activities,but every coin has two sides.While bringing its benefits to people,metal and its compound also make the natural environment and human's health threatened to some extent.Therefore,the detection of metals and their compounds is of great significance.In recent years,fluorescent probe technology has attracted more and more attention from researchers due to its high selectivity,low cost,simple operation and real-time monitoring.spirodifluorene and its derivatives have been widely applied to invarious fields in recent years,especially in the biomedical field represented by fluorescent probes owing to their special structural advantages,such as orthogonal three-dimensional structure,spiral conjugation.However,there are still some room for improvement in selectivity and limit of detection.Considering the above shortcomings,three kinds of Schiff-base fluorescent probes based on spirodifluorene are synthesized.these probes shows excellent selectivity and low limit of detection in the recognition of copper ion,chromium ion and aluminum ion.Part one:Design and Synthesis of Cu²⁺Fluorescent Probe Based on SPF1The UV spectrum,fluorescence spectrum,Job's plot curve,pH titration and other means are used to explore its fluorescent properties and identify some ions.The experimental results show that the probe SPF1 can recognize copper ion.The color of the solution change from blue-green to colorless after adding Cu²⁺,and the compound SPF1 is a fluorescent probe that can efficiently recognize Cu²⁺in the pH range of 2-10,and the detection limit is 0.2?M.The study of the recognition mechanism shows that the ligand and Cu²⁺produce 2:1 Complex,which destroys the intramolecular hydrogen bonds and prevents the lone electron transfer of nitrogen atoms,thereby blocking the ICT process.part two:Design and Synthesis of Cr³⁺Fluorescent Probe Based on SPF-TM1The UV spectrum,fluorescence spectrum,Job's plot curve,pH titration and other means are used to explore its fluorescence properties and identify some ions.The experimental results shows that the probe SPF-TM1 can recognize chromium ion.The color of the solution change from colorless to blue after adding Cr³⁺,and the compound SPF-TM1 is a fluorescent probe that can efficiently recognize Cr³⁺in the p H range of 3-10 with a detection limit of 80nM.The Study on the recognition mechanism shows that the ligand and Cr³⁺produce a 1:2 Complex,which destroys intramolecular hydrogen bonds and prevents the lone electron transfer of nitrogen atoms,thereby inhibiting the PET and TICT process.part three:Design and Synthesis of Al³⁺Fluorescent Probe Based on SPF-TM2The UV spectrum,fluorescence spectrum,Job's plot curve,pH titration and other means are used to explore its fluorescence properties and identify certain ions.The experimental result shows that the probe SPF-TM2 can recognize Al³⁺after adding Al³⁺,The color of the solution changs from blue to colorless,and the compound SPF-TM2 is a fluorescent probe that can efficiently recognize Al³⁺in the pH range of5-10,and the detection limit is 0.1?m.The study of the recognition mechanism shows that the ligand and Al³⁺form a 1:1 complex,causing charge transfer of ligand to metal atom.