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β-diketone compounds exist in two forms: the keto and the enol. The nature of this class of compounds the most significant is the conversion of keto and enol, a phenomenon called keto - enol tautomerism. Generally, enol is more stable than the ketone structure, a ketone - enol tautomeric balance is affected by the polarity of the solvent, a substituted group, pH, light, etc. conditions, ketone - enol The isomerization transition gives attention has been paid many of its unique spectral properties and chemical properties, and thus as an important intermediate for organic synthesis and metal chelating reagent. In this paper, the structure of the β-diketone compounds, the nature of the characteristics, and in recent years, rare earth β-diketone photoluminescence complex research progress. 1H-pyrazole compounds synthesized 15 kinds of aromatic β-diketone, 15 β-diketone derivatives, 15 kinds of rare earth elements Eu (Ⅲ) with β-diketones, phenanthroline, bipyridine binary $ rare earth complexes, specific content is divided into three parts: 1. Use of aromatic ketones and aromatic esters in the presence of a strong base NaNH classic Claisen condensation reaction occurs under the conditions of 2 , 15 β-diketone compounds were synthesized by UV, IR, 1 HNMR their composition and structure, mass spectrometry characterization and determination of the crystal structure of the four kinds of β-diketone, discussed their structural characteristics. The UV results show that, with a strong feature in the ultraviolet region of 320 ~ 400nm absorption, is a class of UV-A ultraviolet absorbers; 1 HNMR results showed that 15 kinds of β-diketone compound keto and enol tautomeric isomers are present, in a chloroform solution, the 15 kinds of β-diketone compounds are mainly present in the enol form (> 90%); crystal structure shows that, due to the strong intramolecular hydrogen bond effect, all four kinds of β-diketones in the enol form. 2. The condensation reaction of β-diketone and hydrazine hydrate, and 15 kinds of β-diketone derivative was synthesized: 1H-pyrazole compound. And by IR 1 HNMR, mass spectrometry of their composition and structure were characterized. MS results show that, due to the NH ... N hydrogen bonds between the molecules, 1H-pyrazol-exist in the form of the dimer. 3. 15 kinds of β-diketone morpholine and rare earth element Eu (Ⅲ) and phenanthroline, bipyridine binary, ternary complexes were synthesized. IR, 1 HNMR, elemental analysis and TG-DTG their composition, structure characterization. IR results showed that the β-diketone ligands relative to the enol form, with a metal ion chelated by the chelating effect, the absorption peak of the IR characteristics of the ligand occurred redshift; fluorescence spectroscopy showed the ligand with the Eu (III) characteristic fluorescence of Eu (Ⅲ) complexes formed were issued, and the fluorescence intensity of the ternary complexes is significantly stronger than the binary complexes, the phenanthroline Synergistic sensitized stronger bipyridine.
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