Preparations, properties, and vibrational spectra of some (dimethylamino)halogenosilanes

Abstract

We have prepared and characterised the new compounds SiH₂Cl(NMe₂), SiH₂Br(NMe₂), SiH₂I(NMe₂), and SiHCl₂(NMe₂). The vibrational spectra of the three (amino)monohalogenosilanes show dramitic changes on solidification, but those of the (amino)dichlorosilane are very similar in all three phases. These differences are discussed in the light of the formation of dimers in the crystalline solid of SiH₂Cl(NMe₂), and the presence of discrete monomers in the crystal of SiHCl₂(NMe₂). The n.m.r. spectra of the compounds, together with that of the monofluorosilane SiH₂F(NMe₂), are reported and discussed briefly.