Calcium Imide, CaNH

Calcium Imide, CaNH, is formed as a greyish-white powder by passing a mixture of hydrogen and nitrogen over heated calcium metal, nitride, or hydride, at 730°- 750° C. It is extremely sensitive to light, a few minutes' exposure causing it to turn a dark brown colour owing to the liberation of calcium nitride in accordance with the following equation: -

4CaNH = Ca(NH₂)₂ + Ca₃N₂.

The reaction may be reversed by heat.

By heating in vacuo, the imide is again formed and ammonia is split off.

Ca(NH₂)₂ = CaNH + NH₃.