 | |||
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| Names | |||
|---|---|---|---|
| Preferred IUPAC name Oxalonitrile[4] | |||
| Systematic IUPAC name Ethanedinitrile[4] | |||
| Other names | |||
| Identifiers | |||
| |||
3D model (JSmol) | |||
| 1732464 | |||
| ChEBI | |||
| ChemSpider |
| ||
| ECHA InfoCard | 100.006.643 | ||
| EC Number |
| ||
| 1090 | |||
| MeSH | cyanogen | ||
| RTECS number |
| ||
| UNII | |||
| UN number | 1026 | ||
| |||
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| Properties | |||
| C2N2 | |||
| Molar mass | 52.036 g·mol−1 | ||
| Appearance | Colourless gas | ||
| Odor | pungent,bitter almond-like | ||
| Density | 950 mg mL−1 (at −21 °C) | ||
| Melting point | −28 °C (−18 °F; 245 K) | ||
| Boiling point | −21.1 °C; −6.1 °F; 252.0 K | ||
| 45 g/100 mL (at 20 °C) | |||
| Solubility | soluble inethanol,ethyl ether | ||
| Vapor pressure | 5.1 atm (21 °C)[5] | ||
Henry's law constant (kH) | 1.9 μmol Pa−1 kg−1 | ||
| −21.6·10−6 cm3/mol | |||
Refractive index (nD) | 1.327 (18 °C) | ||
| Thermochemistry | |||
Std molar entropy(S⦵298) | 241.57 J K−1 mol−1 | ||
Std enthalpy of formation(ΔfH⦵298) | 309.07 kJ mol−1 | ||
Std enthalpy of combustion(ΔcH⦵298) | −1.0978–−1.0942 MJ mol−1 | ||
| Hazards | |||
| Occupational safety and health (OHS/OSH): | |||
Main hazards | formscyanide in the body; flammable[5] | ||
| GHS labelling: | |||
   | |||
| Danger | |||
| H220,H331,H410 | |||
| P210,P261,P271,P273,P304+P340,P311,P321,P377,P381,P391,P403,P403+P233,P405,P501 | |||
| NFPA 704 (fire diamond) | |||
| Explosive limits | 6.6–32%[5] | ||
| NIOSH (US health exposure limits): | |||
PEL (Permissible) | none[5] | ||
REL (Recommended) | TWA 10 ppm (20 mg/m3)[5] | ||
IDLH (Immediate danger) | N.D.[5] | ||
| Safety data sheet (SDS) | inchem.org | ||
| Related compounds | |||
Related alkanenitriles | |||
Related compounds | DBNPA | ||
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |||
Cyanogen is thechemical compound with theformula (CN)2. The simplest stablecarbon nitride, it is acolorless and highlytoxicgas with apungentodor. The molecule is apseudohalogen. Cyanogen molecules consist of two CN groups ‒ analogous to diatomic halogen molecules, such asCl2, but far less oxidizing. The twocyano groups are bonded together at theircarbon atoms: N≡C‒C≡N, though otherisomers have been detected.[6] The name is also used for the CN radical,[7] and hence is used for compounds such ascyanogen bromide (NCBr)[8] (but see alsoCyano radical). When burned at increased pressure with oxygen, it is possible to get a blue tinted flame, the temperature of which is about 4800°C (a higher temperature is possible with ozone). It is as such regarded as the gas with the second highest temperature of burning (afterdicyanoacetylene).
Cyanogen is theanhydride ofoxamide:
though oxamide is manufactured from cyanogen by hydrolysis:[9]
Cyanogen is typically generated fromcyanide compounds. One laboratory method entails thermal decomposition ofmercuric cyanide:
Or, one can combine solutions of copper(II) salts (such ascopper(II) sulfate) with cyanides; an unstable copper(II) cyanide is formed which rapidly decomposes intocopper(I) cyanide and cyanogen.[10]
Industrially, it is created by theoxidation ofhydrogen cyanide, usually usingchlorine over an activatedsilicon dioxidecatalyst ornitrogen dioxide over acopper salt. It is also formed whennitrogen andacetylene are reacted by an electrical spark or discharge.[11]
For the two less stable isomers of cyanogen, the order of the atoms differs. Isocyanogen (or cyanogen cyanide) is NCNC.[12] It has been detected in the interstellar medium]].[13]
Addition of sulfur monochloride to cyanogen gives3,4-dichloro-1,2,5-thiadiazole.
Paracyanogen is apolymer of cyanogen. It can be best prepared by heatingmercury(II) cyanide. It can also be prepared by heatingsilver cyanide,silver cyanate,cyanogen iodide or cyanuric iodide.[14] It can also be prepared by the polymerization of cyanogen at 300 to 500 °C (572 to 932 °F) in the presence of trace impurities. Paracyanogen can also be converted back to cyanogen by heating to 800 °C (1,470 °F).[9] Based on experimental evidence, the structure of this polymeric material is thought to be rather irregular, with most of thecarbon atoms being ofsp2 type and localized domains ofπ conjugation.[15]
Cyanogen was first synthesized in 1815 byJoseph Louis Gay-Lussac, who determined its empirical formula and named it. Gay-Lussac coined the word "cyanogène" from the Greek words κυανός (kyanos, blue) and γεννάω (gennao, to create), because cyanide was first isolated by Swedish chemistCarl Wilhelm Scheele from the pigmentPrussian blue.[16] It attained importance with the growth of thefertilizer industry in the late 19th century and remains an important intermediate in the production of many fertilizers. It is also used as a stabilizer in the production ofnitrocellulose.
Cyanogen is commonly found incomets.[17] In 1910 aspectroscopic analysis ofHalley's Comet found cyanogen in the comet's tail, which led to public fear that the Earth would be poisoned as it passed through the tail. People inNew York wore gas masks, and merchants soldquack "comet pills" claimed to neutralize poisoning.[17] Because of the extremely diffuse nature of the tail, there was no effect when the planet passed through it.[18][19]
Like othercyanides, cyanogen is very toxic, as it readily undergoes reduction to cyanide, which poisons thecytochrome c oxidase complex, thus interrupting themitochondrialelectron transfer chain. Cyanogen gas is an irritant to the eyes and respiratory system. Inhalation can lead to headache, dizziness, rapid pulse, nausea, vomiting, loss of consciousness, convulsions, and death, depending on exposure.[20] Lethal dose through inhalation typically ranges from 100 to 150milligrams (1.5 to 2.3grains).
Cyanogen produces the second-hottest-known natural flame (afterdicyanoacetylene aka carbon subnitride) with a temperature of over 4,525 °C (8,177 °F) when it burns in oxygen.[21][22]
In theDoctor Who serial "The Brain of Morbius" (the 5th serial of season 13), the Doctor synthesizes cyanogen using hydrogen cyanide as a starting material and vents it through a pipe to stop Solon from performing surgery on the brain of Morbius's body.
InDragnet (1987) Friday (Dan Aykroyd) and Streebek (Tom Hanks) are tracking down the villain who stole "the pseudohalogenic compound cyanogen".[23]
In the second season ofThe Night Agent, cyanogen is stolen from a chemical plant as part of a plot to manufacture achemical weapon.
Media related toCyanogen at Wikimedia Commons| Authority control databases: National |
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