Synthesis And Fluorescence Properties Of Pyridyl-Bis-β-Diketones And Their Derivatives

This paper summarizes the structure and properties of the bis-β-diketones and theirderivatives, along with the research status of the luminescence properties of rare earthβ-diketone complexes. We have synthesised five kinds of pyridyl-bis-β-diketone ligands, fivekinds of1H-pyrazol-compound of bis-β-diketone derivatives, five kinds of [1,3,4]oxadiazolecompounds containing pyridine, the boron difluoride complexes of five kinds of bis-β-diketones,nine kinds of rare earth complexes of Eu（III） with bis-β-diketone, bipyridine, phenanthroline.The content is divided into six chapters:1. This section describes the structure and properties of bis-β-diketones and[1,3,4]oxadiazole compounds, as well as the research progress of bis-β-diketone derivatives andlanthanide complexes, and thus leads to the study of the subject content.2.2,6-pyridine-dimethyl ethyl ester was synthesized using2,6-pyridinedicarboxylic acidand ethanol as the materials under microwave irradiation. Five kinds of bis-β-diketone weresynthesized by claisen condensation reaction of methyl ketones compounds and2,6-pyridine-dimethyl ethyl ester. Their structures were characterized by elemental analyser,MS, IR,1H NMR,13C NMR and UV spectra. The data of1H NMR and13C NMR show that thefive kinds of bis-β-diketone in a chloroform solution exists mainly enol structure. The UVspectra show that these compounds have strong absorption of ultraviolet light in the range of280⁴00nm, and can be used as an ultraviolet absorber.3. Five kinds of pyridyl-bis-1H-pyrazole derivatives were synthesised by the reaction ofbis-β-diketone and hydrazine hydrate and their structures were characterized by elementalanalyser, MS, IR,1H NMR. Their fluorescence spectral characteristics have been studied andthe influence of different solvents and different metal ions on their fluorescence intensity hasbeen discussed. The results show that the polar solvents can help to enhance the fluorescenceintensity of these compounds and Ca²⁺ion can enhance the intensity of the fluorescence ofthese compounds, Ni²⁺ion has a strong fluorescence quenching.4. Five kinds of [1,3,4] oxadiazole compounds were obtained by the reaction of2,6-pyridine-dimethyl ethyl ester with hydrazine hydrate, followed by the cyclization withtriethyl orthoformate or aromatic carboxylic acid in the phosphorus oxychloride. Their structures were confirmed by elemental analyser, MS, IR,1H NMR and their fluorescenceproperties were discussed.5. The bis-β-diketone-boron trifluoride complexes were prepared from the reaction ofbis-β-diketone with boron trifluoride ether and their structures were confirmed by elementalanalyser, IR,1H NMR. Their properties of UV and fluorescence were also studied. The resultsindicate that these complexes have good fluorescence-emitting properties, wherein thefluorescence quantum yield of the complexes5d reached0.9.6. The nine kinds of rare earth complexes were prepared by the reaction of bis-β-diketoneligands with Eu（III）, bipyridine and phenanthroline and characterized by elemental analyser andIR spectra. The fluorescence spectroscopy show that the complexes emited the characteristicfluorescence of Eu（III） ion.