Design And Synthesis Of Amide Type Of Fluorescent Small Molecules For Metal Ion Recognition

Molecular recognition is the selective complexation between host and guest in which some special functions can be generated. The complexation process and the corresponding subtle environmental modification could only be identified when they convert to sensitive signal. The fluorescence analysis method has high selectivity and high sensitivity, so it is widely used in recognition, micro analysis and trace analysis of metal ions in recent years.Zinc and iron ions are very important to biological systems which can affect physiological process in many ways. The foundation of the recognition and analysis method is significant for life and environment science. In this thesis, five fluorescent small molecules were synthesized from 2-mercaptopyridine and 2-mercaptobenzothiazole, their fluorescent properties and ion recognition mechanisms were analyzed briefly.The thesis is totally divided into five chapters; the main content can be summarized as follows:In the first chapter, the structures, parameters and recognition mechanisms of fluorescent molecules were reviewed. The conceive of the thesis was put forward in accordance with these theories.In the second chapter, five new fluorescent derivatives of 2-mercaptopyridine and 2-Mercaptobenzothiazole were designed, synthesized and characterized by chemical element analysis and 1H MNR. The fluorescent properties were investigated under different solvent condition.In the third chapter, the fluorescence molecules have better selectivity to Zn²⁺ with the enhanced fluorescence intensity. So this kind of small molecules could be used as good Zn²⁺ fluorescent sensors based on fluorescence enhancement.In the fourth chapter, the fluorescent molecules show better selectivity to Fe³⁺ in DMF solvent. Fe³⁺ can quench the fluorescence with a strong ability of disturbance resistance. So this kind of small molecules could be used as good Fe³⁺ fluorescent sensors based on fluorescence quenching.In the last chapter, gave out conclusion and prospect.