Alkali‐Salze des Octamethylcyclotetrasilazans – Synthese und Kristallstrukturen

Alkali Salts of Octamethylcyclotetrasilazane ‐ Synthesis and Crystal Structures Octamethylcyclotetrasilazane reacts with n ‐butyllithium or the elements sodium and potassium to give the alkali salt 1 , 2 , and 3. 1 – 3 crystallize as dimeric THF adducts. In the dimers two eight‐membered rings are connected by a planar alkali metal‐nitrogen four‐membered ring. Lithium is tricoordinated in 1 , sodium tetracoordinated in 2 , and potassium penta‐ and hexacoordinated in 3 . The crystal structures of the alkali salts are discussed and compared with one another. The coordinatively bonded TH in the lithium compound 1 can be exchanged with the Lewis base TMEDA. The crystal structure of 4 shows a higher symmetry than that of 1 .