不对称双Salamo型四肟3d-4f金属超分子配合物的结构调控及发光性能研究

3d-4f Heteropolynuclear metal supramolecular complexes have been highly appreciated due to their novel topology and optical, electrical, magnetic, catalytic and adsorption properties. However, the Salamo-type multi-oxime complexes have still been in its infancy. Lately, it is demonstrated that rational design and careful selection of special organic ligands should be one of the key approaches in constructing 3d-4f heteropolynuclear metal supramolecular complexes. Oxime compounds with unique basic unit (-C=N-O-) are not only easy to coordinate with the soft transition metal ions but also with the hard rare earth metal ions. And as organic ligands with unmatched coordination ability and flexible coordination mode are usually used to construct the metal complexes with intriguing architectures and excellent properties. Consequently, oxime compounds are the preferred ligands to construct 3d-4f heteropolynuclear metal complexes. Furthermore, the rare earth and transition metal ions exhibit weak selectivities under complicated coordination conditions, partially leading to homometallic complexes due to the competitive reaction between two different types of metal ions with organic ligands. Therefore, it remains an elusive scientific challenge for the chemists and crystallographers to select and design suitable building units and assemble them into the 3d-4f heteropolynuclear metal supramolecular complexes with predictive structure and function. In this project, we design and prepare a series of novel unsymmetrical double Salamo-type tetra-oxime ligands by the building units of three diamines (1,2-bis(aminooxy)ethane, 1,3-bis(aminooxy)propane and 1,4-bis(aminooxy)butane), 2,3-dihydroxybenzene-1,4-dicarbaldehyde and 2,3-dihydroxynaphthalene-1,4- dicarbaldehyde etc. The Job plots curves of the ligands vs Zn(II), Cd(II) ions are studied by UV-vis titration method to get the coordination ratio of target complexes. Successively the 3d homopolynuclear and 3d-4f heteropolynuclear metal complexes will be synthesized and characterized by physicochemical and spectroscopic methods, respectively. The single crystals of these complexes are obtained in aid of vapor diffusion method, natural evaporation method and solvent thermal method, etc. And the crystal structures are determined by X-ray diffraction method to further study their supramolecular features. The influence of flexibility and substituent group of the ligands, sovent effects as well as counter anions on constitution, structure and physicochemical properties of the complexes are also discussed. The fluorescent properties of the complexes are studied through static fluorescence determination to explore the influence of the transition metal ions on the triple state of the unsymmetrical tetra-oxime ligands. As a result we can tune the rare earth luminescence effectively to afford excellent luminescent materials, and apply them to the luminescence devices.

3d-4f异多核金属超分子配合物因具有新颖的拓扑结构和光、电、磁、催化和吸附等性能而倍受青睐，但其Salamo型多肟配合物的研究还处于起步阶段。申请项目拟设计合成新颖的不对称双Salamo型四肟配体；利用紫外-可见光谱滴定法确定锌(II)、镉(II)等金属离子对上述双Salamo型四肟配体的Job plots图，研究其配位规律；按照最佳反应配比分别合成这些过渡金属离子的3d同多核金属配合物及其钐(III)、铕(III)、铽(III)、镝(III)等稀土离子的3d-4f异多核金属配合物，探讨其超分子结构；研究配体柔曲性、溶剂效应、取代基效应和抗衡阴离子等因素对3d-4f异多核金属配合物的组成、结构及其物理化学性质的影响。借助于静态荧光测定法研究目标配合物的荧光性质，探寻过渡金属离子对四肟配体三重态的调节并有效敏化稀土离子发光的规律，寻求性能优良的发光材料。

Salen型金属配合物因具有新颖的拓扑结构和光、电、磁、催化和吸附等性能而倍受青睐，但其衍生物Salamo型多肟配合物的研究还处于起步阶段。本项目从研究目标出发，得到了具有以2,3-二羟基-1,4苯二醛和2,3-二羟基-1,4萘二醛为母体的双Salamo型配体及其相应的3d、3d-4f、3d-2s配合物。探讨了系列配合物的构效关系，系统研究了配合物的结构、光化学性能、分子磁性以及选择性识别。研究结果表明：双Salamo型配体末端基的改变对配合物的结构基本没有影响，特别是在配位体系中同时引入3d、3d-4f、3d-2s金属离子时，这类配体以类冠醚空腔螯合稀土离子或s区离子，而在N2O2配位环境螯合3d金属。这两个不同螯合性能的螯合位点对稀土、s区离子以及3d金属离子的选择性配位作用不明显。但在配位时仍体现了配合物形成过程中的软硬酸碱规则：稀土倾向于和硬碱氧原子配位且达到较高的配位数10或11。其次，在对这两类双Salamo型配体及其配合物的研究过程中我们发现，具有d10电子构型3d金属可较好的敏化稀土离子的发光性能，而不具有d10电子构型的3d金属离子对稀土离子的发光性能影响较大，但是，这类配合物展现出了独特的磁性，因此，我们对这类配合物进行了系统的磁性研究，另外，所合成的3d-2s配合物在儿茶酚催化氧化活性的研究中也展现出了较高的催化活性。最后，在本基金的支持下，我们制备出了结构新颖、同时具有磁、光双功能的Zn-Ln杂金属的配位聚合物，总结了化合物的成键规律和构效关系。本项目的研究成果不仅丰富了稀土元素配位化学和无机合成化学的研究内容，而且对丰富功能配合物的研究领域有重要的理论指导意义和潜在的应用前景。