Synthesis And Luminescence Properties Of A Novel 2,6-Pyridinic Acid Derivative And Its Rare Earth Complexes

The excellent properties of rare earth elements such as light and electricity make it to be an important element in the development of modern industry.Rare earth elements have been widely utilized to construct magnetic,luninescent materials and for sensing application due to their characteristic electronic preoerties.Due to the limitation of the parity rule,the probability of f?f transition in rare earth ions is small,however,this could be overcome by forming rare earth complex in aid of incorpation of organic ligands with high absorption coefficient to obtain bright luminescent rare earth materials.2,6-pyridinedicarboxylic acid not only possesses strong UV absorption capacity but also has biological activity.Therefore,2,6-pyridinedicarboxylic acid derivatives are excellent organic ligands for constructing rare earth copounds.It is expected that the luminescence of rare earth ions can be effectively sensitized to get high color purity,long luminescence lifetime,and high quantum yield by forming rare earth compound based on2,6-pyridinedicarboxylic acid derivatives.The results in my thesis are important for the development of new display materials and sensing materials for providing some theoretical support and have potential application value.In this thesis,a new 2,6-pyridinedicarboxylic acid derivative was synthesized by using2,6-pyridinedicarboxylic acid as starting material and the synthetic route of the compound was optimized.On this basis,its coordination chemistry was studied together with the luminescent properties of the rare earth complex.The content of this paper is divided into the following four parts:1.The research progress of rare earth complexes,especially luminescent rare earth complexes,and the significance of this paper are reviewed.2.A novel pyridine carboxylic acidlig and,4-[?Bis-pyridin-2-ylmethyl-amino?-methyl]-pyridine-2,6-dicarboxylic acid?H₂L?was synthesized using 2,6-pyridinedicarboxylic acid as starting material from five steps.The factors affecting the yield of intermediates and H₂L was studied.The reaction conditions for each step was optimized to obtain a reasonable route.Furthermore,the coordination behavior of H₂L in solution was investigated.3.Fluorescence tests show that the compound H₂L can effectively sensitize rare earth ion luminescence in aqueous solution.The reacted solution of compound H₂L and rare earth ions can recognize Zn²⁺ions:after adding Zn²⁺ions,the fluorescence intensity of Tb³⁺characteristic emission in solution is increased by 9.6 times,the binding constant bound to Zn²⁺ions is 8.76×10⁶.Obtained from the Job's plot and fluorescence titration results,the molar ration of Zn²⁺to Tb³⁺complex was 3:1.4.Results and prospects:A new 2,6-pyridinedicarboxylic acid derivative was prepared and its coordination chemistry with rare earth elements was studied.The research content of this thesis lays a foundation for the synthesis and fluorescence properties of the rare earth complexes of this compound.