Synthesis And Performance Study Of Fluorescent Probes Based On Bisalicylaldehyde

Metal ions widely exist in nature,and they play an important role in the life,growth and development of organisms.Excessive or insufficient intake of metal ions will damage various functions of the body,and ultimately cause life-threatening.Therefore,it is great significant to realize the qualitative and quantitative detection of metal ions.Fluorescent molecular probes are widely used in many fields because of their high selectivity,sensitivity and easy operation,and their ability to selectively transform the chemical signals of analytical objects into fluorescent signals easily measured in instrumental analysis.Design and synthesis of fluorescence probes based on bisalicylaldehyde and apply them to the study of different metalions in this paper.The main contents of this paper are as follows:1.Synthesis of bissalicylaldehyde 4,4’-dihydroxybenzene was used as starting material and trifluoroacetic acid as solvent to synthesize compound4,4’-dihydroxybenzene-3,3’-dimethylaldehyde by formylation.The yield of this step was 92.0%.2.Synthesis of 3-chloro-2-hydrazinopyridine 3-chloro-2-hydrazinopyridine was synthesized by nucleophilic substitution reaction of 2,3-dichloropyridine with hydrazine hydrate under high pressure.The yield of the reaction was 83.5%.3.Synthesis of Schiff base fluorescent probes The liquid phase synthesis method was used to synthesize Schiff base fluorescent probes by condensation reaction of salicylaldehyde with 3-chloro-2-hydrazinopyridine in solution under heating reflux.The yield of the reaction was 90.3%.4.Fluorescence detection of metal ions The prepared Schiff base fluorescence probe was applied to the detection of metal ions,which can realize the fluorescence detection of Al³⁺.The fluorescence intensity can be enhanced 17times after the recognition of Al³⁺.At the same time,the interference of Ba²⁺,Ca²⁺and other metal ions can be avoided,and the rapid and efficient detection of Al³⁺can be realized.The structures of intermediates and products were characterized by infrared spectroscopy and nuclear magnetic resonance.