Synthesis And Optimization Of Fluoride Ion Fluorescent Probe Based On ESIPT Mechanism

At present,fluoride ions have a huge influence in the natural environment as well as in human production and life.For example,fluoride is widely used in dental hygiene products such as toothpaste and mouthwash to prevent dental caries.In addition,fluorine is a common anesthetic,psychotropic substance and nerve gas.Fluoride ion is also very important to the human body.The proper amount of fluoride ion is necessary for the human body,and excessive intake of fluoride ion will seriously endanger human health and cause various diseases.At the same time,due to the limitations of traditional fluoride ion detection methods such as potential analysis and ion chromatography,it is gradually replaced by a simple and sensitive fluorescent molecular probe.Using the strong nucleophilic interaction between fluorine and silicon,we combine the luminescent reagent with silane to form a silane compound,and the fluoride ion is added to break the silicon-oxygen bond,so that the fluoride ion concentration can be accurately quantified.In the previous studies,the excited state proton transfer(ESIPT)process mechanism was used as a way to open the fluorescence to design the probe.In this experiment,the probe 1 and probe 2 and optimized probe 2+Zn were synthesized using the excellent performance of the AIE effect fluorescent substance aggregation induced luminescence combined with the ESIPT process mechanism.And the following main contents:? In this paper,2-hydroxy-5-methoxybenzaldehyde,p-aminobenzene and tert-Butylchlorodiphenylsilane were used as raw materials to synthesize Schiff base fluorescent ion probe 1 and 2-aminopyridine.A pyridyl Schiff base-based fluoride ion fluorescent probe was synthesized in two steps with 2-hydroxy-5-methoxybenzaldehyde and tert-Butylchlorodiphenylsilane as reactants.It was characterized by mass spectrometry and nuclear magnetic 1H HMR.? Exploring the ESIPT process mechanism of probe 1 and probe 2 reacting with fluoride ion,respectively.?The response time,sensitivity and detection limit of probe 1 and probe 2 were obtained by titration of fluorescence spectrum and ultraviolet absorption spectrum after adding fluoride ion(DL probe 1=3.1×10-6M,DL probe 2=1.8×10-4M),thereby the fluorescent probe 1 with the AIE effect,the photochemical signal,higher sensitivity and shorter response time was obtained.In order to improve the performance of probe 2,we successfully synthesized a novel organometallic fluorescent probe 2+Zn by using zinc ion combined with probe 2.?The results show that the new fluorescent probe 2+Zn has high stability,and the response time,reaction rate and fluorescence signal intensity of the probe 2+Zn to fluoride ion are explored by fluorescence and absorption spectroscopy.Needle 2+Zn has a higher fluorescence intensity visible to the naked eye under UV light,shorter response time,and a lower order of magnitude than the probe 2.