Ammonium cyanide

Ammonium cyanide
Identifiers
CAS Number	12211-52-8 ;
3D model (JSmol)	Interactive image;
ChemSpider	140210 ;
PubChem CID	159440;
UNII	898Y75UR3N ;
CompTox Dashboard (EPA)	DTXSID00153500 ;
	InChI InChI=1S/CN.H3N/c1-2;/h;1H3/q-1;/p+1 Key: ICAIHGOJRDCMHE-UHFFFAOYSA-O ; InChI=1/CN.H3N/c1-2;/h;1H3/q-1;/p+1 Key: ICAIHGOJRDCMHE-IKLDFBCSAW;
	SMILES [C-]#N.[NH4+];
Properties
Chemical formula	[NH4]CN
Molar mass	44.0559 g/mol
Appearance	colourless crystalline solid
Density	1.02 g/cm3
Melting point	36 °C (decomp.)
Solubility in water	very soluble
Solubility	very soluble in alcohol
Structure
Crystal structure	cubic
Related compounds
Other anions	Ammonium hydroxide; Ammonium azide; Ammonium nitrate;
Other cations	Sodium cyanide; Potassium cyanide;
Related compounds	Ammonia; Hydrogen cyanide;
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Ammonium cyanide is an unstable inorganic compound with the chemical formula N H₄CN. It is the ammonium salt of hydrogen cyanide. It consists of ammonium cations NH+4 and cyanide anions CN⁻. Its structural formula is [NH₄]⁺[C≡N]⁻.

Uses

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

Ammonium cyanide is prepared by combining solutions of hydrogen cyanide and ammonia:

HCN + NH₃ → NH₄CN

It may be prepared by the reaction of calcium cyanide and ammonium carbonate:

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:

KCN + NH₄Cl → NH₄CN + KCl

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 + (CH₃)₂CO → (CH₃)₂C(NH₂)CN + H₂O

Ammonium cyanide is highly toxic.

^ 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.

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