Studies On Fluorescent Sensors For Heavy Metal Ions And Functional Lanthanide Complexes

Quinoline and Imine derivatives have strong coordination ability and can modulate metal center electronic properties; they have been widely used in catalytic oxidation, analytical chemistry, bioscience, and functional material. Herein, we designed and synthesized a series of sensors based on quinoline receptor and evaluated their binding ability and fluorescence sensing for metal ions in aqueous media. In addition, new lanthanide complexes with flexible open-chain Schiff base ligands have been synthesized and characterized. Their near-infrared luminescence properties and supramolecular structures influenced by terminal group、central skeleton and lanthanide contraction have also been investigated in detail. The dissertation is divided into six parts:1. The research background of supramolecular chemistry is concisely reviewed. We focus on the research progress of self-assembly chemistry and host-guest chemistry and the fluorescence response mechanism of organic molecule sensor.2. We have synthesized a novel reaction-based CuⅡ probe in aqueous media under visible light excitation. Cu-mediated benzyl ether C-O bond cleavage offers excellent selectivity and turn-on fluorescent response. Confocal microscopy experiments have demonstrated that the probe is membrane permeable and can detect intracellular CuⅡ.3. A highly selective and reversible two-photon fluorescent probe was designed and synthesized. It shows ratiometric response upon addition of Cd2+due to the ICT structure in the excited state of the H2L-Cd complex in aqueous media.4. Based on the work in the previous chapter, in order to optimize the properties of probe, we designed and synthesized a new naphthalimide-based two-photon fluorescent probe for Cd2+. The probe is still capable of detecting cadmium in the water system. The two-photon fluorescence microscope imaging shows that the probe is membrane permeable and can detect intracellular Cd2+.5. New flexible chain ligand based on8-hydroxyquinoline and its lanthanide complexes were prepared and characterized. Their structures and near-infrared luminescence properties were discussed in detail.6. A series of flexible open-chain Schiff base ligands and their lanthanide complexes have been synthesized and characterized. Their supramolecular structures influenced by terminal group, central skeleton, anions and lanthanide contraction were discussed in detail.