Ammonium cyanide

Ammonium cyanide
Space-filling model of the ammonium cation	Space-filling model of the cyanide anion
Identifiers
CAS Number	12211-52-8 ;
3D model (JSmol)	Interactive image;
ChemSpider	140210 ;
PubChem CID	159440;
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	NH4CN
Molar mass	44.0559 g/mol
Appearance	colourless crystalline solid
Density	1.02 g/cm3
Boiling point	36 °C
Solubility in water	very soluble
Solubility	very soluble in alcohol
Related compounds
Other anions	Ammonium hydroxide; Ammonium azide; Ammonium nitrate
Other cations	Sodium cyanide; Potassium 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 formula NH₄CN.

Uses

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

Preparation

Ammonium cyanide is prepared in solution by bubbling hydrogen cyanide into aqueous ammonia at a low temperature

HCN + NH₃(aq) → NH₄CN(aq)

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

Reactions

Ammonium cyanide decomposes to ammonia and hydrogen cyanide; often forming a black polymer of hydrogen cyanide:

NH₄CN → NH₃ + HCN

It undergoes double decomposition reactions in solution with a number of metal salts. It reacts with glyoxal producting glycine (aminoacetic acid):

NH₄CN + (CHO)₂ → NH₂CH₂COOH + HCN

Reactions with ketones yield aminonitriles:

NH₄CN + CH₃COCH₃ → NH₂CH₂CH₂CH₂CN + H₂O

Toxicity

The solid or its solution is highly toxic. Ingestion can cause death. Exposure to the solid can be harmful as it decomposes to highly toxic hydrogen cyanide and ammonia.

Chemical Analysis

Elemental composition: H 9.15%, C 27.23%, N 63.55%.

Ammonium cyanide may be analyzed by heating the salt and trapping the decomposed products. Hydrogen cyanide and ammonia in water at low temperatures. The aqueous solution is analyzed for cyanide ion by silver nitrate titrimetric method or an ionselective electrode method; and ammonia is measured by titration or electrode technique.

References

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