Ammonium cyanide is an unstable inorganic compound with the formula NH4CN.

Uses

Ammonium cyanide is generally used in organic synthesis.[citation needed] Being unstable, it is not shipped or sold commercially.

Preparation

Ammonium cyanide is prepared by combining solutions of hydrogen cyanide and ammonia:[citation needed]

HCN + NH3 → NH4CN

It may be prepared by the reaction of calcium cyanide and ammonium carbonate:[citation needed]

Ca(CN)2 + (NH4)2CO3 → 2 NH4CN + CaCO3

In dry state, ammonium cyanide is made by heating a mixture of potassium cyanide or potassium ferrocyanide with ammonium chloride and condensing the vapours into ammonium cyanide crystals:[citation needed]

KCN + NH4Cl → NH4CN + KCl

Reactions

Ammonium cyanide decomposes to ammonia and hydrogen cyanide, often forming a black polymer of hydrogen cyanide:[1]

NH4CN → NH3 + HCN

It undergoes salt metathesis reaction in solution with a number of metal salts to form metal–cyanide complexes.

Reaction with ketones and aldehydes yield aminonitriles, as in the first step of the Strecker amino acid synthesis:

NH4CN + CH3COCH3 → (CH3)2C(NH2)CN + H2O

Toxicity

Further information: Cyanide poisoning

Ammonium cyanide is highly toxic.

Notes

  1. ^ Matthews, Clifford N (1991). "Hydrogen cyanide polymerization: A preferred cosmochemical pathway". Bioastronomy: The Search for Extraterrestrial Life—The Exploration Broadens. Lecture Notes in Physics. Vol. 390. pp. 85–87. doi:10.1007/3-540-54752-5_195. ISBN 978-3-540-54752-5.

References

  • A. F. Wells, Structural Inorganic Chemistry, 5th ed., Oxford University Press, Oxford, UK, 1984.