基于大环空腔包裹构型的发光稀土配合物的设计合成和光物理性质研究

The preparation of lanthanide(III) complexes with excellent luminescence has always been one of the key and difficult fields in functional materials, and “shell-type” configuration is considered as a potential solution. During the research of macrocyclic Ln(III) complexes, it is found that the Ln(III) ions could not be encapsulated by macrocyclic cavities and this is the critical factor resulting in unsatisfactory luminescence. Here we plan to construct a variety of “shell-type” substrates which the cavities of Schiff-base macrocycles could encapsulate Ln(III) ions with different energy levels of the lowest excited states. Finally, we hope to obtain novel photoluminescent complexes in good performance after further optimizing strategy. Several aspects are focused on this project. Firstly, two series of extended dialdehydes derived from the classic dialdehyde (4-substituted-2,6-diformylphenol) will be carefully designed and synthesized while different types of matched diamines could be acquired by the commercial methods. Secondly, by examination of several parameters (e.g., the concentration of precursors, solvent, anion, reaction time, etc.), highly efficient Schiff-base cyclic condensation reactions based on lanthanide ion template method are aimed for. Thirdly, the photophysical properties (e.g., emission spectrum, lifetime, excited energy levels, energy transfer, etc.) together with crystal structures in the encapsulated macrocyclic substrates will be carefully measured and analyzed. Then mechanisms of sensitization and the relationships between the encapsulated configurations and luminescent performances will be investigated. Lastly, the influence of counterions, functional groups and neutral organic ligands for macrocyclic substrates on luminescence will be studied in depth. And a series of lanthanide complexes with remarkable luminescence will be achieved. By the exploration of cyclic macrocyclic cavities in “shell-type” lanthanide complexes, the expected results will provide valuable references for the development of new sensitizers and rare earth luminescent materials.

制备发光性能出色的稀土配合物一直是功能材料研究中的重难点，“包裹型”结构设计在这方面极具潜力。在研究大环稀土配合物时，发现很难利用空腔进行结构上的包裹保护，这是制约其高效发光的关键。本项目拟以Schiff碱大环为敏化剂，针对激发态能级不同的各种稀土离子，通过设计空腔可容纳稀土离子的“包裹型”大环基底，并进一步有针对性地优化调控，制备出光物理性质优良的新型发光稀土配合物。主要研究内容包括：系列二醛和二胺前驱体的设计合成和筛选；稀土离子模板法环缩合反应的参数设置和反应规律；“包裹型”Schiff碱大环稀土配合物基底的结构、光物理性质（发射光谱、寿命、激发态能级、能量传递过程等）、敏化机理和结构-发光构效关系研究；抗衡离子、功能基团以及中性配体对基底发光性能的优化调控。该研究旨在运用环状大环空腔来构筑“包裹型”发光稀土配合物，预期结果将为新型配体和稀土发光材料的研制提供有价值的参考。

制备发光性能出色的稀土配合物一直是功能材料研究中的重难点，“包裹型”结构设计在这方面极具潜力。在研究大环稀土配合物时，发现很难利用空腔进行结构上的包裹保护，这是制约其高效发光的关键。本项目拟以Schiff碱大环为敏化剂，针对激发态能级不同的各种稀土离子，通过设计空腔可容纳稀土离子的“包裹型”大环基底，并进一步有针对性地优化调控，制备出光物理性质优良的新型发光稀土配合物并用作光学分子传感器进行相关分析物的响应研究。主要研究内容包括：系列二醛和二胺前驱体的设计合成和筛选；稀土离子模板法环缩合反应的参数设置和反应规律；“包裹型”Schiff碱大环稀土配合物基底的结构、光物理性质（发射光谱、寿命、激发态能级、能量传递过程等）、功能基团对基底发光性能的优化调控及其响应性能探索（选择性、灵敏度、响应时间和潜在应用等）。最终，我们设计并制备出了系列“包裹型”Schiff碱大环Sm(III)配合物，详细研究了发光机理，并利用其成功地进行四氢呋喃和锂离子的响应研究。该研究旨在运用环状大环空腔来构筑“包裹型”发光稀土配合物，预期结果将为新型配体和稀土发光材料的研制提供有价值的参考。