Synthesis and Structure of Methoxybis[tris(trimethylsilyl)silyl]methane – The First Geminal Di(hypersilyl) Compound with a Central Carbon Atom
✍ Scribed by Jeschke, Elke ;Gross, Thoralf ;Reinke, Helmut ;Oehme, Hartmut
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1996
- Tongue
- English
- Weight
- 469 KB
- Volume
- 129
- Category
- Article
- ISSN
- 0009-2940
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✦ Synopsis
Methane, methoxybis[tris(trimethylsilyl)silyl-/ Tris(trimethylsily1)silyllithium / Dichloromethyl methyl ether /
Poly silanes
Methoxy-bis[tris(trimethylsilyl)silyl]methane (4), the first compound bearing two hypersilyl groups at a carbon atom, was synthesized by the reaction of tris(trimethylsily1)silyllithium with dichloromethyl methyl ether. As a byproduct of the reaction, 1,2-dimethoxy-1,2-bis[tris(trimethylsilyl)silyl]ethane ( 5 ) could be identified. Possible pathways leading to 4 and 5 are discussed. The structure of 4, elucidated by an Xray crystal structure analysis, is characterized by tremendous distortions of the molecular skeleton due to the spatial de-mand of the two extended hemispherical (MesSi)3Si groups.
For example, the central Si-C-Si angle is widened to 132.7", the trimethylsilyl groups of the two hypersilyl substituents are pressed together to give an average Si-Si-Si angle of 105.6", and the methoxy carbon atom and the nearest neighboring trimethylsilyl carbon atom approach to a distance of 3.25 A, i.e. approx. 19% less than the sum of the van der Waals radii of two methyl groups.