Four‐, Five‐, and Six‐Coordinate Silicon(IV) Complexes: Reactivity of the Donor‐Stabilized Silylenes [ i PrNC(Ph)N i Pr] 2 Si and [ i PrNC(N i Pr 2 )N i Pr] 2 Si Towards Me 3 SiN 3 and PhSCH 2 N 3

Bis(amidinato)silylene 1 and the analogous bis(guanidinato)silylene 2 reacted with Me 3 SiN 3 to form compounds 3 [a five‐coordinate silicon(IV) complex with an Si=N double bond] and 4 [a four‐coordinate silicon(IV) complex with an Si=N double bond], respectively. For compound 3 , a dynamic equilibrium between a five‐ and four‐coordinate silicon(IV) species in solution was observed (at –95 °C, these species are stable on the NMR spectroscopic timescale), whereas 4 is four‐coordinate in solution. Treatment of 1 with PhSCH 2 N 3 afforded compound 5 (isolated as 5a·5b· 0.5 n ‐C 6 H 14 ), which is a cocrystallizate of the diastereomers 5a and 5b with half an n ‐hexane molecule in the asymmetric unit. The diastereomers 5a and 5b [six‐coordinate silicon(IV) complexes with an unsubstituted methyleneamido ligand and an SiN 5 S skeleton] differ only in their interchanged positions of their thiophenolato and methyleneamido ligands. In solution, a dynamic equilibrium between 5a and 5b was observed.