cyanide

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cyanide

(sī`ənīd'), chemical compound containing the cyano groupcyano group
, in chemistry, functional group that consists of a carbon atom joined to a nitrogen atom by a triple bond; it can be joined to an atom or another group by a single bond to the carbon atom. When a cyano group is joined to hydrogen, it forms hydrogen cyanide.
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, -CN. Cyanides are salts or esters of hydrogen cyanidehydrogen cyanide,
HCN, colorless, volatile, and extremely poisonous chemical compound whose vapors have a bitter almond odor. It melts at −14°C; and boils at 26°C;. It is miscible in all proportions with water or ethanol and is soluble in ether.
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 (hydrocyanic acid, HCN) formed by replacing the hydrogen with a metal (e.g., sodium or potassium) or a radical (e.g., ammonium or ethyl). The most common and widely used cyanides are those of sodium and potassium; they are often referred to simply as "cyanide." Both are white, crystalline, chemically active compounds. They are used as insecticides, in making pigments, in metallurgy (e.g., electroplating and case hardening), and in refining gold and silver by the cyanide processcyanide process
or cyanidation,
method for extracting gold from its ore. The ore is first finely ground and may be concentrated by flotation; if it contains certain impurities, it may be roasted.
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. Organic cyanides are called nitriles. The ethyl ester of hydrogen cyanide (CH3CH2CN) is called variously ethyl cyanide, propionitrile, propane nitrile, nitrilopropane, and cyanoethane; propane nitrile is the approved name in the nomenclature system for organic chemistry adopted by the International Union of Pure and Applied Chemistry (IUPAC). Most cyanides are deadly poisons that cause respiratory failure. Symptoms of cyanide poisoning include an odor of bitter almond on the breath, dizziness, convulsions, collapse, and, often, froth on the mouth. In case of cyanide poisoning a doctor should be summoned immediately. If the poison was swallowed, vomiting should be induced. Artificial respiration should be used if needed.

Cyanide

 

a salt of hydrocyanic acid. The cyanide salts of the alkali metals MCN and the alkaline-earth metals M(CN)2, where M is a metal, are thermally stable but are hydrolyzed in aqueous solutions. The cyanides of the heavy metals are thermally unstable and, with the exception of Hg(CN)2, are insoluble in water.

The oxidation of cyanides leads to the formation of cyanates; for example, 2KCN + O2 → 2KOCN. Many metals upon the action of an excess of potassium cyanide or sodium cyanide yield complexes. This proves useful in the extraction of gold and silver from ores (cyanidation, cyanide process):

4NaCN + 2Au + ½O2 + H2O → 2Na[ Au(CN)2] + 2NaOH

Gold and silver are separated from solution by electrodeposition or by the action of metallic zinc. Solutions of the cyanide complexes of gold, silver, zinc, and other metals are used in electroplating technology for the production of coatings. Cyanides are also used in organic synthesis, for example, in the production of nitriles, and as catalysts (in benzoin condensation).

Cyanides are extremely toxic. (For information on the effect of cyanides on the organism and on safety measures when handling them, seeHYDROCYANIC ACID.)

REFERENCES

Bobkov, S. S., and S. K. Smirnov. Sinil’naia kislota. Moscow, 1970.
Zil’berman, E. N. Reaktsii nitrilov. Moscow, 1972.
Tomilov, A. P., and S. K. Smirnov. Adipodinitril i geksamet ilendiamin. Moscow, 1974.
Williams, H. E. Cyanogen Compounds, 2nd ed. London, 1948.
Migrdichian, V. The Chemistry of Organic Cyanogen Compounds. New York, 1947.
Methoden der Organischen Chemie (Houben-Weyl), 4th ed., vol. 8. Stuttgart, 1952.

S. K. SMIRNOV

cyanide

[′sī·ə‚nīd]
(inorganic chemistry)
Any of a group of compounds containing the CN group and derived from hydrogen cyanide, HCN.

cyanide

, cyanid
1. any salt of hydrocyanic acid. Cyanides contain the ion CN-- and are extremely poisonous
2. another name (not in technical usage) for nitrile
References in periodicals archive ?
It has also been reported [1, 3, 15], that cyanide levels of plants vary according to the environments where they grow.
The ingestion of cyanide or a cyanogenic glycoside can trigger off a lot of toxic manifestations.
Oberg and colleagues used the Atacama Large Millimeter/submillimeter Array in Chile to detect radio waves emitted by the cyanide molecules.
A vapor of hydrogen cyanide, methyl cyanide and cyanoacetylene swirls around the star MWC 480, about 460 light-years away in the constellation Auriga.
Grandmother Christine, who comes from Hednesford but lives in Huntington, Cannock, is now personally accredited as what is known as a lead cyanide auditor by the International Cyanide Management Institute (ICMI).
Alkali metal cyanides such as sodium and potassium cyanide are lost from surface waters mainly by volatilization, while other soluble metal cyanides are removed primarily by precipitation and biodegradation [2].
1976, "Mathematical analysis of the chemical system cyanide heavy meals in water determination of components and toxicity of the system-I.
2003, "Destruction of cyanide in gold mill effluents: biological versus chemical treatments," Biotechnol.
Suicide: Cyanide, in the form of pure liquid prussic acid (a historical name for hydrogen cyanide), was also a favoured suicide agent of the Third Reich.
With both nitrate and cyanide poisoning, prevention is truly easier than the cure.
The report will be of considerable interest primarily to relevant strategic planners, senior company officials and importers/exporters, since it features invaluable information on cyanides, cyanide oxides and complex cyanides export/import operations segmented by country and region.
Cyanokit is in development for the treatment of known or suspected cyanide poisoning and is currently marketed in France by Merck KGaA affiliate Merck Sante.