Siliconitrogen Hydride, SiNH

Siliconitrogen Hydride, SiNH, which is the silicon analogue of hydrocyanic acid, is formed by the action of ammonia on silicochloroform vapour:

SiHCl₃ + 4NH₃ = SiNH + 3NH₄Cl.

The gases are diluted with hydrogen and cooled to prevent a too vigorous reaction, and moisture and air are rigorously excluded to prevent hydrolysis or oxidation of the product. Ammonium chloride is removed from the mixture by means of liquid ammonia, but the hydride has not been obtained pure.

Siliconitrogen hydride is a white powder which sublimes with decomposition at 300° C. under reduced pressure. It reacts with water and alkalis, producing silicic acid or a silicate, ammonia and hydrogen:

SiNH + 3H₂O = H₂SiO₃ + NH₃ + H₂;

it is consequently a strong reducing agent, and in this respect resembles silicoformic anhydride. Dry hydrogen chloride gas regenerates silico-chloroform, thus:

SiNH + 4HCl = SiHCl₃ + NH₄Cl.

Evidently siliconitrogen hydride does not resemble hydrogen cyanide.