The preparation and properties of dimethylamino- and diethylaminosilane
Dimethylaminosilane and diethylaminosilane have been prepared almost quantitatively from the reactions of iodosilane with dimethylamine and diethylamine. Physical properties, including infrared and mass spectra, are reported and discussed, and a new value for the heat of association of solid SiH3NMe2 is presented. Pyrolysis of these aminosilanes leads mainly to disproportionation about silicon. Both compounds behave as weak Lewis bases. With hydrogen chloride, the initial products at –96° are SiH3NMe2,2HCl and SiH3NEt2,3HCl; these adducts (which may be ionic in nature) decompose at higher temperatures to give chlorosilane and dialkylammonium chloride. With trimethylborane and SiH3NEt2, a weak 1 : 1 adduct is formed, whilst iodosilane affords the more robust adducts SiH3NR2,SiH3l (R = Me, Et).