Donor-Acceptor Stabilized Tetra(silanimine).

The synthesis of an oligo(silanimine) is described. The reaction of the amidinato silylene [LSiN(SiMe)] (1, L = PhC(NtBu)) with SiI in toluene afforded a mixture of the silanimine [LSi(I)NSiI] (2), SiMeI, and SiI. The mechanistic studies showed that 1 reacts with SiI to form the silyl ionic intermediate "{LSi(I)N(SiMe)}{SiI}", which then eliminates SiMeI and "SiI" to form the silanimine intermediate "LSi(I)NSiMe". It further undergoes a substitution with another molecule of SiI to form a mixture of 2 and SiMeI. In addition, "SiI" undergoes an oxidative addition with SiI to form SiI. Subsequently, compound 2 reacted with [LiN(SiMe)Ar] to form the silanimine [LSi(I)NSiIN(SiMe)Ar] (6, Ar = 2,6-iPrCH), which was then treated with KC to give the donor-acceptor stabilized tetra(silanimine) [LSiN(SiMe)SiNAr] (7). It comprises four formal silanimine ">Si═N-" units, which are linked together. Compounds 2, 6, and 7 were characterized by NMR spectroscopy and X-ray crystallography.