含氮螯合配体支持的二价稀土化合物的合成、结构及其性能研究

Organolanthanide complexes as new catalytic materials have been studied extensively, especially divalent lanthanide complexes with an excellent catalytic activity attracted attention. The project focuses on modern synthetic technology and ion exchange methods, including the design of new series of amino and amidino ligands, synthesis of structurally novel divalent lanthanide complexes with low coordination numbers, growth of X-ray quality crystals for in-depth structural analysis and by other characterization methods (NMR, IR, and elemental analysis). The current study will be carried out in terms of chemical reactivity, catalytic applications (C-C coupling), polymerization, activation of small molecules ( such as carbon monoxide, hydrogen), and biomimetic chemistry (such as nitrogen fixation) to explore the reaction mechanism and improve the preparation of environmentally friendly rare earth materials. This project not only deals with the preparation of novel rare earth materials, it also promotes the multidisciplinary integration of chemistry, material, environment and energy.

有机稀土材料作为一种新型催化材料被广泛研究，尤其是二价稀土有机化合物具有更为优异的催化活性而倍受关注。本项目旨在设计系列胺基，脒基配体，利用无水、无氧合成技术和离子交换化学方法，合成出一类结构新颖具有低配位数晶态二价稀土金属有机络合物。通过多种手段进行其结构表征（单晶，核磁，红外，元素分析）, 并研究该类络合物"二价稀土-还原"在有机反应中碳-碳偶联，单体聚合，小分子活化(如一氧化碳、氢气等)，生物固氮等方面的应用，揭示金属络合物催化反应机理，筛选出具有高效、环境友好型稀土催化或发光材料。本项目不仅为制备新型稀土材料提供一条崭新的途径，也可以促进化学、材料、环境和能源等学科的交叉融合。

二价稀土的合成具有一定挑战性，其性能研究相对较少，有待探索。本项目主要集中描述吡啶胺基配体 [N(R)(2-C5H3N-6-Me)]- (R = SiMe3, SiButMe2), 苯胺基配体[R2Si(NC6H3 Pri2-2,6)2]2- (R = Me or Ph) 及帶有取代集团环戊二稀基配体[C5H3(SiMe3)2]- 与稀土金属络合的配位化学, 对其合成结构及反应性能的研究。首先讨论了由吡啶胺基配体所絡合二价稀土的制备及结构表征. 通過合成[(L1)K(tmeda)]2 [Ln = N(R)(2-C5H3N-6-Me)]- (n =1, R = SiMe3; n = 2, SiButMe2)与之相对应的二价铕和镱的碘化物反应, 低价铕和镱的配合物[Ln(Ln)2(tmeda)] (n = 1, Ln = Yb (1), Eu (4); n = 2, Ln = Yb (2)); [(L1)3YbK(THF)] (3) 和 [(L2)3EuK(tmeda)] (5)成功被合成. 由L1 配位的二价钐和镝并不成功,得到相对应的三价络合物。 另外, 二价钐的环戊二稀土络合物 [(Cp'')2Sm(THF)] (Cp'' = C5H3(SiMe3)2) (8), 比较穩定,容易被合成; 进一步与不饱和类有机物反应,成功得到化合物 [(Cp'')2Sm(NC6H11)2 CC(H11C6N)2 Sm(Cp'')2] (9)。最后描述了苯胺基配体与低价稀土的系列反应化学。通过K2(Ln)(THF)x (Ln = R2Si(NC6H3Pri2-2,6)2 (n = 3, R = Me; n =4, R = Ph)) 与稀土碘化物交換反应. 通过配体比例控制,可得到二价镱一系列化合物[(Ln)2Ln{K(THF)2}2] (n = 4, Ln = Yb (17); n = 3, Ln = Yb (18); 並成功得到单核化合物 [(L4)Yb(THF)3] (16)，进一步利用此类配体欲合成还原性更強的化合物。