Alkali Metal Silanides

Alkali Metal Derivatives with Heavy Group 14 Ligands 2.01.3.1 Alkali Metal Silanides... 

Over the past decade alkali metal silanides have gained importance due to their application as reagents in synthetic chemistry, resulting in an upsurge of detailed information available on such compounds. Several review articles... 

Since then, several different alkali metal silanide systems have been reported. One of them, the hypersilyl [Si(SiMe3)3] ligand, was first prepared by Gilman and Smith.172, 173 Another ligand includes supersilyl [SPBuJ-prepared in 1975.174-176 Several other variations of the ligand systems are known with the recent addition of [SkB Ph]-, for which several alkali metal derivatives have been prepared and characterized.177,178... 

Alkali metal silanides, characteristics, 2, 18 Alkali metal stannides, characteristics, 2, 23 Alkaline earth metals... 

All alkali metal hypersilanides display highly pyramidal central silicon centers with Si-Si-Si angles around 100°. Remarkably, these angles do not differ in the contact or separated ion pairs, further indicating the large degree of charge transfer from the alkali metal cation to the silanide anion. The pyramidalization is also an expression of the increased />-character of the Si-Si bond, and consequent increase in the alkali metal-silicon bond. 

Stable homoleptic tetraorganyldielement compounds characterized by crystal structure determinations are summarized in Table III. Their syntheses succeeded by three methods (i) Reduction of element(III) compounds by alkali metals (ii) treatment of subhalides with the corresponding alkyllithium compounds (iii) reactions of particular silanides... 

Klinkhammer KW (1997) Tris(trimethylsilyl)silanides of the heavier alkali metals - a structural study. Chem Eur J 3 1418... 

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