Rare earth metal complexes bearing thiophene-amido ligand: Synthesis and structural characterization
作者:Dun Wang、Dongmei Cui、Wei Miao、Shihui Li、Baotong Huang
DOI:10.1039/b708881g
日期:——
2,6-Diisopropyl-N-(2-thienylmethyl)aniline (H2L) has been prepared, which reacted with equimolar rare earth metal tris(alkyl)s, Ln(CH2SiMe3)3(THF)2, afforded rare earth metal mono(alkyl) complexes, LLn(CH2SiMe3)(THF)3 (1: Ln = Lu; 2: Ln = Y). In this process, H2L was deprotonated by one metal alkyl species followed by intramolecular C–H activation of the thiophene ring to generate dianionic species L2− with the release of two tetramethylsilane. The resulting L2− combined with three THF molecules and an alkyl unit coordinates to Y3+ and Lu3+ ions, respectively, in a rare N,C-bidentate mode, to generate distorted octahedron geometry ligand core. Whereas, with treatment of H2L with equimolar Sc(CH2SiMe3)3(THF)2, a heteroleptic complex (HL)(L)Sc(THF) (3) was isolated as the main product, where the dianionic L2− species bonds to Sc3+via chelating N,C atoms whilst the monoanionic HL connects to Sc3+ in an S,N-bidentate mode. All complexes 1–3 have been characterized by NMR spectroscopy and X-ray diffraction analysis.
制备了 2,6-二异丙基-N-(2-噻吩基甲基)苯胺 (H2L),并将其与等摩尔稀土金属三(烷基)Ln(CH2SiMe3)3(THF)2 反应,得到稀土金属单(烷基)配合物 LLn(CH2SiMe3)(THF)3(1:Ln = Lu;2:Ln = Y)。在此过程中,H2L 被一个金属烷基物种去质子化,然后噻吩环被分子内 C-H 活化,生成二离子物种 L2-,并释放出两个四甲基硅烷。生成的 L2- 与三个 THF 分子和一个烷基单元结合,分别以罕见的 N、C-配位模式与 Y3+ 和 Lu3+ 离子配位,生成畸变八面体几何配位体核心。而用等摩尔的 Sc(CH2SiMe3)3(THF)2 处理 H2L 后,分离出的主要产物是异极配合物 (HL)(L)Sc(THF) (3),其中二阴离子的 L2- 物种通过螯合 N、C 原子与 Sc3+ 结合,而单阴离子的 HL 则以 S、N 共轭模式与 Sc3+ 连接。所有复合物 1-3 都已通过核磁共振光谱和 X 射线衍射分析进行了表征。