The Synthesis And Properties Of Perylene Probes Modified By Fluorine

Perylene diimides(PDIs) represent a class of organic chromophores with photochemical stabilities, high extinction coefficients, and high quantum yields. PDIs are key chromophores for high-tech applications, such as organic optoelectronic devices, biolabeling, and single molecular spectroscopy. Electronegativity of fluorine atom is strong and atomic radius of it was small. Fluorinated compounds display a variety of excellent properties, such as thermal stability, chemical stability, and cytocompatibility. Therefore, the study of fluorinated compounds has attracted more and more attention. In this thesis, we mainly studied the electrochemical-photophysical properties of PDIs with fluorinated substituents on the bay, and applications for cellular imaging. The main contents are as follows.1. Fluorinated perylene diimides(FPDI-1,FPDI-2) and PPDI were obtained by introducing fluorinated substituents and benzene substituents respectively into the bay of PDI. The optical and electrochemical properties of the three compounds were investigated. In chloroform solution, they all possessed high fluorescence quantum yields(59%-63%) and excellent optical stability. With fluorinated benzene on the bay, the maximum absorption and emission of the FPDIs were both blue-shifted. With the number of fluorine atoms increased, the lowest unoccupied molecular orbital(LUMO) levels of PPDI, FPDI-1 and FPDI-2 reduced gradually from-3.82 e V to-3.96 e V. And the highest occupied molecular orbital(HOMO) levels of the three compounds decreased gradually from-5.89 e V to-6.12 e V.2. By introducing the PEG chains into the end and head of imides, we synthesized the perylene probes(BFPDI-1,BFPDI-2 and BPPDI) with good water-solubility. We investigated their electrochemical-photophysical properties and applications for cellular imaging. With the number of fluorine atoms increased, the fluorescence quantum yields of the three compounds in water were gradually improved from 15% to 36%. They all possessed good water solubility, biocompatibility and pH stability. The brightness of fluorescence images and fluorescence stability in cells were gradually improved with the number of fluorine atoms increased. Among the three probes, the performance of BFPDI-2 was the best.