Aluminium cyanide

Aluminium cyanide is a metallic cyanide with a chemical formula of Al(CN)3. It is a white solid that undergoes hydrolysis to produce aluminium hydroxide and hydrogen cyanide.

Synthesis and properties
Aluminium cyanide was first produced in 1924 as its ammoniate, Al(CN)3·5NH3, by reacting aluminium metal and mercury(II) cyanide in liquid ammonia to prevent hydrolysis.
 * 2 Al + 3 Hg(CN)2 → 2 Al(CN)3 + 3 Hg

When the ammoniate contacts water, it produces aluminium hydroxide, ammonia, and ammonium cyanide.

The pure compound was produced in 2001 by the reaction of lithium tetrachloroaluminate and trimethylsilyl cyanide in diethyl ether and its crystals form an octahedral Prussian-blue-like structure.