荧光导向d-f异核MOFs的设计、构筑、协同敏化荧光及构效关系研究

To the target of currently outstanding problems for lanthanide luminescent imaging materials, which is, the excitation spectrum is in the ultraviolet region, and the emission fluorescence is very weak. The novel conjugated ligands will be designed and synthesized for preparing the near-infrared fluorescence crystalline materials, based on novel d-f heterometallic coordination polymers, through the solvo/iono-thermal or microwave synthesis approache by controlling reaction conditions, which is high luminescence, thermally stable, low-cost, and is unavailiable through the traditional method. The fluorescence modulation mechanism will be exploited via studying how the transition metal-organic coordination unit, ionic liquid, organic ligands sensitize the lanthanide ion, cooperatively. How the syntheses conditions, materials compositions, ligand structures, chromospheres, introduction ancillary ligand to modulate the fluorescence properties, especially fluorescence quantum efficiency will be investigated in details, based on the density function theory calculation. Some of the new methods and theories of preparation, structures, quantum efficiency and spectral modification for the near-infrared fluorescent lanthanide crystal materials with strong fluorescence, long lifetime, tunable excitation spectrum will be explored. The factors result in the materials fluorescence enhancing or quenching will be elucidated, followed by some of models based on electronic transferring, charge transition, energy conversion being established. Some of new ideas and experimental facts for biological imaging materials based on d-f heterometallic polymers will be provided through this research.

针对目前稀土荧光成像材料在紫外区激发、发光强度较低的突出问题，设计、合成新颖的共轭配体，控制反应条件，利用溶剂热、离子热、微波合成手段制备稳定性好、光致发光强度高、成本低廉、传统方法无法获得的，在生物医学成像方面具有潜在应用价值基于新型d-f异核配位聚合物近红外荧光晶体材料。通过研究后过渡金属配位单元、离子液体、有机配体对发光离子的协同敏化作用，阐明d-f异核配位聚合物的光谱调制、转换机理。在量化计算的基础上研究配体的结构、发色基团和辅助配体的引入对荧光性能调控和对量子效率的影响。探索发光效率高、寿命长、激发波长可调控的新型近红外荧光材料的制备方法，及荧光光谱调制的一些新理论。探讨影响d-f异核聚合物晶体材料荧光增强、猝灭的因素，建立电子传递、电荷跃迁、能量转移模型，为基于新型d-f异金属MOFs荧光成像材料的研究提供新思路和实验依据。

针对目前稀土荧光成像材料在紫外区激发、发光强度较低的突出问题，围绕实现高效荧光材料的设计与合成目标,设计、合成了新颖的共轭配体，控制反应条件，利用溶剂热、微波合成等手段制备得到稳定性好、光致发光强度高、成本低廉、传统方法无法获得的，在生物医学成像方面具有潜在应用价值基于d-f异核新型配位聚合物的近红外荧光晶体材料。项目执行过程中，合成了3种刚柔性不同的共轭配体，进一步制备了系列四个系列d-f异核MOFs晶态化合物，对它们的分子结构、发色基团的单线态、三线态能级和化合物的激发和发射光谱进行的系统测试、分析。获得了关联发色基团的结构、稀土离子及抗阳离子的种类、材料结构及分子间弱作用等因素与目标化合物的NIR发光性能构效关系信息。揭示LMCT、MLCT、发光离子之间共振（合作）能量转移过程及NIR荧光增强机理, 进一步探索了材料微观结构与发光性能的关系。依据实验结果加上理论计算对激发态形成、光谱调控和d-f能量传递协同敏化、NIR 发光机理进行探讨，获得的发光性能好、可以在可见区域被激发系列近红外荧光材料。还通过研究后过渡金属Co，Zn配位单元、共轭有机配体对稀土离子的配位场改善，研究了d-f异核聚合物的单分子磁体的性能，阐明磁驰豫机理。