【作者】 张云；

【导师】 崔鹏；

【作者基本信息】 安徽师范大学 ， 化学， 2023， 硕士

【摘要】 本论文合成并表征了一系列七齿N₃P₄配体支撑的稀土-钴键配合物,研究了稀土-钴键配合物催化的N₂硅烷化反应,主要包括以下内容:1.设计合成了一个具有更大“空腔”的七齿N₄P₃配体LH₃。通过与稀土金属三烷基配合物（Me₃Si CH₂）₃Ln（THF）₂（Ln=Sc,Lu,Yb,Y,Gd）的烷烃消除反应合成得到了三胺基配合物LLn（Ln=Sc,Lu,Yb,Y,Gd）,并通过¹H,¹³C{¹H},³¹P{¹H}NMR,X-射线单晶衍射以及元素分析进行了表征。随后,通过三胺基配合物LLn与一价钴前体（PPh₃）₃Co I反应,分离得到相应的稀土-钴碘配合物LLn Co I（Ln=Sc,Lu,Yb,Y,Gd）,后者再与K[HBEt₃]和18-c-6在N₂气氛下发生还原反应得到N₂配位的稀土-钴键配合物[LLn Co N₂][（18-c-6）K（THF）_x]（Ln=Sc,Lu,Yb,Y,Gd）,并通过¹H,¹³C{¹H},³¹P{¹H}NMR,红外光谱,电化学,以及X-射线单晶衍射进行了表征,其中钴中心处于-1价氧化态。理论计算进一步表明这是首例含有稀土-钴键的杂核配合物。2.研究了稀土-钴键氮气配合物在KC₈和Me₃Si Cl存在下,催化N₂转化为（Me₃Si）₃N的反应。发现了不同的稀土-钴键氮气配合物具有不同的催化活性,其中镥-钴键氮气配合物表现出最高的催化活性（16 TONs）,这与晶体结构中观察到的配位N₂分子被活化的强弱次序并不一致,表明催化N₂硅烷化反应活性受到稀土金属的Lewis酸性、离子半径以及膦配体的供电子能力等综合因素的控制。通过进一步合成单钴配合物LH₃Co I,并对比其在相同条件下的催化活性,揭示了在该体系中稀土金属Lewis酸不可或缺的作用机制,展示了稀土Lewis酸中心通过金属间相互作用对于钴中心上的N₂官能团化反应独特的调控作用。更多还原

【Abstract】 This dissertation studied the syntheses of heptadentate N₄P₃ ligand supported rare-earth-cobalt bonded complexes and their catalytic reactivity toward N₂ functionalzation,which included following parts:1.A heptadentate N₄P₃ ligand LH₃ with greater ligand cavity was designed and synthesized,which was reacted with rare-earth metal trisalkyl complexes（Me₃Si CH₂）₃Ln（THF）₂（Ln=Sc,Lu,Yb,Y,Gd）under alkane elimination conditions to afford corresponding trisamide complexes LLn.These complexes were characterized by NMR spectroscopy,X-ray diffraction studies and elemental analysis.Treatment of LLn with the Co（I）precursor（Ph₃P）₃Co I led to the isolation of rare-earth-cobalt iodide complexes LLn Co I,which was further reduced with K[HBEt3]in the presence of 18-c-6 under N₂ atmosphere to afford a series of rare-earth-cobalt bonded complexes[LLn Co N₂][（18-c-6）K（THF）_x]（Ln=Sc,Lu,Yb,Y,Gd）with N₂ molecule coordinated on the Co（-I）center.These complexes were fully characterized by NMR and IR spectroscopies,electrochemical strudies and X-ray diffraction analysis.Computational studies revealed that these compunds represented the first series of heterbiometallic complexes featuring a rare-earth-cobalt bond.2.The catalytic activity of comeplxes[LLn Co N₂][（18-c-6）K（THF）_x]toward N₂silylation with Me₃Si Cl was studied,which demonstrated that with different supporting rare-earth metals different activity was achieved.The Lu-Co complex exhibited highest TON of 16 within the series,which is not fully consistent with the trend of N₂-activation observed in their solid-state structures,leading to the conclusion that catalytic activity of N₂-silylation is influenced by the Lewis acidity and ionic radii of the rare-earth metal ions,together with the electron donating ability of phosphine donors.Comparsion of the catalytic activity with the mono-cobalt complex LH₃Co I clearly showed that the rare-earth metals were essential not only to achieve the catalytic turnovers,but also to tune their activity via the Ln-Co bonds.更多还原