Synthesis and structural characterisation of mixed alkali metal–magnesium mixed ligand alkyl-amido ate complexes
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- 作者：Prokopis C. Andrikopoulos ; David R. Armstrong ; Alan R. Kennedy ; Robert E. Mulvey ; Charles T. O’ ; Hara ; René ; B. Rowlings ; Susan Weatherstone
- 关键词：Alkali metal ; Magnesium ; Amide ; Agostic ; X-ray crystallography ; Ate ; Heterobimetallic
- 刊名：Inorganica Chimica Acta
- 出版年：2007
- 出版时间：1 March 2007
- 年：2007
- 卷：360
- 期：4
- 页码：1370-1375
- 全文大小：326 K
文摘
Using two different reaction methodologies, two alkali metal–magnesium alkyl bis(amide) complexes were synthesised. First the lithium magnesiate LiMg{μ-N(SiMe3)2}2(tBu) (1) was prepared by combining equimolar quantities of tBuLi and Mg{N(SiMe3)2}2 in hydrocarbon solvent. An X-ray crystallographic study revealed that the asymmetric unit of 1 has a dinuclear arrangement, based on a planar Li–N–Mg–N four-membered ring. As a result of the presence of intermolecular agostic interactions between the Li centre of one asymmetric unit and a methyl group which is resident on the terminal tert-butyl group of another, 1 is polymeric in the solid-state. Second the sodium magnesiate NaMg{μ-N(SiMe3)2}2(tBu) · (OEt2) (2) was prepared by reacting two molar equivalents of Na{N(SiMe3)2} with one molar equivalent of tBuMgCl in hydrocarbon/diethyl ether solution. X-ray crystallographic analysis revealed that the asymmetric unit of 2 consisted of a dinuclear molecular arrangement. As expected it is not polymeric due to the coordination of the Lewis basic ether. Stabilizing intramolecular agostic NaC bonds are observed (where C is a methyl group resident on a Si atom).