The Studies On Synthesis Of Chromatin Derivatives As Fluorescent Probes For Detecting Zn²⁺?Al³⁺?Cu²⁺ And S^2-

In this paper,three kinds of Schiff base fluorescent probes were designed and synthesized by using 6-hydroxy-3-formyl chromone as fluorophore.Their structures were characterized by ¹H NMR,IR spectroscopy,mass spectrometry,etc.,and their fluorescence properties were also studied.The paper consists of five chapters.The main contents are as follows:Chapter 1:Introduction of fluorescent probes,the application of aluminum,zinc,copper,and sulfur ions to the development of highly relevant fluorescent probes.Chapter 2:the colorimetric and fluorescence-enhanced fluorescent probe L¹ for Al³⁺was synthesized from chromone and 3-hydroxy-2-naphthoyl.The probe has higher selectivity to Al³⁺than other metal ions.High sensitivity and low detection limit.More importantly,L¹ can be used as a potential colorimetric probe for Al³⁺,and the color change of the solution from colorless to yellow can be easily observed by the naked eye in the presence of Al³⁺.Chapter 3:Ligand L² was synthesized from chromone and rhodamine B hydrazide to detect Zn²⁺and Al³⁺based on two different mechanisms.The probe L² has higher selectivity to Zn²⁺than other metal ions,higher sensitivity and lower detection limit.The selective recognition of Zn²⁺by L² is attributed to the interaction of the chromone moiety with Zn²⁺,which inhibits the PET process.Furthermore,we have found that the ligand-metal complex LZn can be used as a ratiometric fluorescent probe to selectively sense Al³⁺with a FRET mechanism.More importantly,the probe L² exhibits excellent fluorescence sensing performance even in a solid state.Chapter 4:Ligand L³ was synthesized from chromone and 7-diethylamine coumarin hydrazide for the detection of Cu²⁺and S^2-based on two different mechanisms.It can be used as a quenching fluorescent probe for the selective detection of Cu²⁺ions without interference from other common metal ions.The obtained metal complex is an excellent S^2-selective fluorescent probe and constitutes an ON-OFF-ON type fluorescent recognition system.When the ligand L³is integrated with Cu²⁺,the color of the solution changes from yellow to orange and the fluorescence emission is weakened until it disappears.The S^2-has a strong affinity for Cu²⁺ions and forms a stable product Cu²⁺with low solubility,and Cu²⁺is removed from the complex to restore the fluorescence of the ligand L³ itself.The reversibility experiment shows that the complex can be recycled many times.More importantly,the metal complex LCu exhibits excellent fluorescence sensing properties even in the solid state.Chapter 5:Summary and outlook on our work.