Ln(AlMe4)3 as New Synthetic Precursors in Organolanthanide Chemistry: Efficient Access to Half-Sandwich Hydrocarbyl Complexes
Ln(AlMe4)3 as New Synthetic Precursors in Organolanthanide Chemistry: Efficient Access to Half-Sandwich Hydrocarbyl Complexes
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DOI：
10.1021/om0506163
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发表时间：
2005-10
期刊：
影响因子：
2.8
通讯作者：
H. Dietrich;Clemens Zapilko;E. Herdtweck;R. Anwander
中科院分区：
文献类型：
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作者：
H. Dietrich;Clemens Zapilko;E. Herdtweck;R. Anwander
同感络合物Ln(AlMe4)3 （Ln = Y, La, Nd, Lu）与五甲基环戊二烯反应得到相应的半夹层络合物（C5Me5）Ln(AlMe4)2，收率高，纯度高。核磁共振波谱研究表明，即使在- 85°C下，桥接和末端烷基也具有高度动态的性质。在固体状态下，四甲基铝配体与金属中心的配位不同，如镧衍生物的x射线结构分析所示。由于大镧金属中心的空间不饱和，其中一个铝酸盐配体采用异常扭曲的μ:η - 3配位模式，而第二个配体以常规的μ:η - 2方式成键。（C5Me5）Y(AlMe4)2与HOCHtBu2醇解反应得到异感络合物（C5Me5）Y(OCHtBu2)（AlMe4）。（C5Me5）Nd(AlMe4)2与脱水周期介孔二氧化硅MCM-41反应，得到表面接枝的（C5Me5）Nd(AlMe4)2@MCM-41。半茂金属双（铝酸盐）配合物转化为无供体[…]
The homoleptic complexes Ln(AlMe4)3 (Ln = Y, La, Nd, Lu) were reacted with pentamethylcyclopentadiene to yield the corresponding half-sandwich complexes (C5Me5)Ln(AlMe4)2 in high yield and purity. NMR spectroscopic investigations revealed a highly dynamic nature of the bridging and terminal alkyl groups, even at −85 °C. In the solid state, the tetramethylaluminato ligands coordinate differently to the metal center, as shown by an X-ray structure analysis of the lanthanum derivative. Due to the steric unsaturation of the large lanthanum metal center, one of the aluminate ligands adopts an unusual distorted μ:η3 coordination mode, while the second ligand bonds in a routine μ:η2 fashion. An alcoholysis reaction of (C5Me5)Y(AlMe4)2 with HOCHtBu2 gave the heteroleptic complex (C5Me5)Y(OCHtBu2)(AlMe4). (C5Me5)Nd(AlMe4)2 was reacted with dehydrated periodic mesoporous silica MCM-41, affording surface-grafted (C5Me5)Nd(AlMe4)2@MCM-41. The half-metallocene bis(aluminate) complexes were converted into donor-free [(...