Silylated amido nitrogen

Starting with the 1-amino-siloxanes, further substitutions turn out to be more complicated. Lithium salts of these compoimds form, depending on the properties and bulkiness of the silyl groups, 1,3-disilazane-l-olates or the less stable l-amido-l,3-disiloxanes. The first case includes a 1,3-silyl group migration from the oxygen to the nitrogen atom. 

In the solid-state structure of the adduct 2 (Fig. 1), a polymeric chain structure is observed in which the potassium cations connect adjacent ytterbate anions via interactions with two amido nitrogen atoms and five trimethylsilyl carbon atoms. The ytterbium atom shows a trigonal planar coordination by the silyl and amido ligands, with a Yh-Sil bond length of 303.87(10) pm. In addition, there are two short intramolecular contacts to trimethylsilyl carbon atoms. 

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