Manipulating the Substituent Sphere of a Bicyclic Silicon(I) Ring Compound Results in Anionic Cubane-Type Clusters and a Tetrahedral Silanide.

The reaction of the bicyclic silicon(I) ring compound Si{N(SiMe)Mes} 1 with strong zwitterionic character and moderate sterical demand of the amido substituents with two equivalents of KC was investigated. This resulted in the unexpected abstraction of two amido substituents from 1 and additionally in dimerization to a dianionic Si cluster compound 2 with four unsubstituted silicon atoms and two [K([18]crown-6)] counter cations. Performing this reaction in the absence of [18]crown-6 results in release of only one amido substituent from 1 and dimerization to a dianionic Si cluster 3 with only two unsubstituted silicon atoms. This reaction with KC was repeated and trapping agents such as SiMeCl and tBuCl were added in-situ whereupon the second isolated homocyclic silylene 4 and a monoanionic hydride and tBu substituted Si cluster 5 with one unsubstituted silicon atom were isolated. Furthermore, 1 was reacted with KOtBu which resulted in the selective abstraction of one SiMe group and formation of the tetrahedral silanide 6 with one imido substituent bridging an edge of the tetrahedron.