Studies On Spectroscopy Properties Of BODIPY Dyes And Non-Cyclic Crown Ether With Its Alkaline Earth Metal Complexes

Fluorescent probes are widely used as powerful tools to spy on molecular recognition events owing to their high sensitivity, selectivity and simple handling. The design of an efficient fluorescent probe for specific analyte has received a growing attention. In this dissertation, we present the spectroscopy properties of BODIPY dyes and non-cyclic crown ether with its alkaline earth metal cation. The dissertation is composed of three chapters.In chapter one, we simply introduce the background of this work, such as fluorescence, the development of boron dipyrromethene (BODIPY) fluorophores and non-cyclic crown ethers.In chapter two, the photophysical properties of meso-Dichloropyrimidy1-BODIPY dyes which are substituted by nucleophiles have been studied, and discussed the substituents, solvent polarity effect on the photophysical properties.In chapter three, a new symmetric polioxo ethylene chain fluorescent probe containing 2-aminoanthracene bichromophoric as terminal group for alkaline earth metal cation, 2,2'-[oxybis(3-oxapentamethyleneoxy)]-bis[N-(2-anthryl)benzamide)] (L1) has been synthesised. The photophysical properties of L1 has been studied by means of absorption, fluorescence spectroscopy and 1H NMR. The different in emission spectra response to concentration of model compound 2-acetamido-anthracene and L1 in acetonitrile implies that intermolecular excited dimers is likely to occur. Fluorescence decay profiles of 2-acetamido-anthracene can be described by a bi-exponential fit, while three lifetimes which two of them similar as those of 2-acetamido-anthracene are found for L1. The third lifetime might be attributed to intramolecular excited dimers. Complex formation with alkaline earth metal ions are investigated in acetonitrile as solvent via fluorimetric titrations. Fluorescence intensity trend of the complex with Mg2-differed from those of other alkaline earth metal ions. The compound forms 1:2 (ligand:Mg2+) complex with Mg2+ while formed 1:1 complexes with Ca2+, Sr2+ and Ba2+, producing large hypochromic shifts in the emission spectra and significant cation-induced fluorescence amplifications. On the contrary, the addition of Ca2+ or Sr2+ or Ba2+ lead to decrease of the fluorescence emission first, then increase and blue shift in emission could be found at the end.