Cyanogen iodide

Cyanogen iodide

Skeletal formula of cyanogen iodide
Ball and stick model of cyanogen iodide Spacefill model of cyanogen iodide
Names
IUPAC name Carbononitridic iodide
Systematic IUPAC name Iodoformonitrile
Other names Iodine cyanide
Identifiers
CAS Number	506-78-5 Y
ChemSpider	10046 Y
EC Number	208-053-3
Jmol 3D model	Interactive image
PubChem	10478
RTECS number	NN1750000
InChI InChI=1S/CIN/c2-1-3 Y Key: WPBXOELOQKLBDF-UHFFFAOYSA-N Y
SMILES IC#N
Properties
Chemical formula	CNI
Molar mass	152.9219 g mol−1
Appearance	White crystals
Density	1.84 g mL−1
Melting point	146.7 °C (296.1 °F; 419.8 K)
Solubility in water	Reacts
Thermochemistry
Std enthalpy of formation (ΔfHo298)	160.5–169.1 kJ mol−1
Vapor pressure	{{{value}}}
Related compounds
Related alkanenitriles	Hydrogen cyanide Thiocyanic acid Cyanogen bromide Cyanogen chloride Cyanogen fluoride Acetonitriles Aminoacetonitrile Glycolonitrile Cyanogen
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Cyanogen iodide or iodine cyanide (ICN) is a pseudohalogen composed of iodine and the cyanide group. It is a relatively volatile and highly toxic inorganic compound. It occurs as white crystals that react slowly with water to form hydrogen cyanide.

Synthesis

Cyanogen iodide is prepared by combining I₂ and a cyanide, most commonly sodium cyanide in ice-cold water. The product is extracted with ether.

I₂ + NaCN → NaI + ICN

Applications

Cyanogen iodide has been used in taxidermy as a preservative. Generally, cyanogen iodide is used for destroying all lower forms of life.

History

Cyanogen iodide was considered one of the impurities in commercially sold iodine before the 1930s.

Hazards

Cyanogen iodide is toxic if inhaled or ingested and may be fatal if swallowed or absorbed through the skin. Cyanogen iodide may cause convulsions, paralysis and death from respiratory failure. It is a strong irritant and may cause burns to the eyes and skin if contact is encountered. If cyanogen iodide is heated enough to undergo complete decomposition, it may releases toxic fumes of nitrogen oxides, cyanide and iodide. A fire may cause the release of poisonous gas. Cyanogen iodide decomposes when contacted with acids, bases, ammonia, alcohols, and with heating. ICN slowly reacts with water or carbon dioxide to produce hydrogen cyanide.

Solutions in pyridine

Cyanogen iodide solutions in pyridine conduct electric current. Dilute solutions of ICN in pyridine are colorless at first, but upon standing become successively yellow, orange, red-brown and deep red-brown. This effect is due to a change in conductivity, which in turn is due to the formation of an electrolyte. When electrical conductivity of ICN is compared with that of iodine-pyridine solutions, the formation of the electrolyte in ICN proceeds much more slowly. Results confirm that cyanides are much weaker salts in pyridine than are iodides, although cyanogen iodide solutions are able to be dissolved in pyridine giving solutions with electrical conductivity that increases over time and results in maximum values.