Studies On The Synthesis And Properties Of The Multi-ion And Small Biomolecule Chemosensors

Due to the high selectivity, high sensitivity and the dynamic working range, chemosensors have attracted a great of interestsin chemistry, biochemistry and environment field. Currently, the studies of the Near-infrared (NIR) fluorescent chemosensor and the chemosensor which recognize the anion, the cation and the small biomolecule play an important role in the practical application. On the basis of the prior works of our group, a simple and novel multi-ion chemosensor has been designed and synthesized. Thus, we have characterized their structure, and studied the recognition of the ligand to multi-ion in the different modes. The traditional chemosensors are not easy to penetrate into tissue. But cyanine dyes are widely employed as fluorescence labels for NIR imaging, since they are compounds with large extinction coefficient and relatively high quantum yield. In terms of this, two Near-infrared (NIR) fluorescent chemosensors which recognized glutathione in the aqueous solution, have been designed and synthesized. Then the interactions between the ligand and the target molecules were discussed, as well as how they influence the properties of the chemosensors.The thesis is divided into four parts:1. A brief review of investigation progress of multi-ion chemosensor and Near-infrared (NIR) fluorescent chemosensor were summarized.2. A novel and simple multi-ion chemosensor,5-diethylamino-2-(quinolin-8-yliminomethyl)-phenol (HL), has been designed by using8-aminoquinoline as the central skeleton. The composition and structure of the organic ligand have been characterized by elemental analysis, NMR, and mass spectrometry. Then we studied the recognition of the ligand to multi-ion in the different conditions. The spectroscopy analysis and DFT calculations were used to evaluate the steric configuration of ligand and the interaction between the ligand and target molecules. What’s more, we demonstrate the application of the ligand in the cells.3. Based on the reaction between the thiol and α,β-unsaturated ketone, we designed and synthesized two Near-infrared (NIR) fluorescent chemosensors (LN1and LN2). The composition and structure of the organic ligands have been characterized by elemental analysis, NMR, and mass spectrometry. Then we studied the recognition of the ligands to Glutathione in the aqueous solution. The interactions between the ligand and the target molecules were discussed here, as well as how they influence the properties of the chemosensors.