parouse.com
 Parouse.com



Cyanogen is the chemical compound with the formula (CN)2. It is a colorless, toxic gas with a pungent odor. The molecule is a pseudohalogen. Cyanogen molecules consist of two CN groups – analogous to diatomic halogen molecules, such as Cl2, but far less oxidizing. The two cyano groups are bonded together at their carbon atoms: N≡C−C≡N, although other isomers have been detected.[6] Certain derivatives of cyanogen are also called "cyanogen" even though they contain only one CN group. For example, cyanogen bromide has the formula NCBr.[7] Cyanogen is the anhydride of oxamide:

H2NC(O)C(O)NH2 → NCCN + 2 H2O although oxamide is manufactured from cyanogen by hydrolysis:[8]

NCCN + 2 H2O → H2NC(O)C(O)NH2 Contents

1 Preparation 2 Paracyanogen 3 History 4 Safety 5 See also 6 References 7 External links

Preparation[edit] Cyanogen is typically generated from cyanide compounds. One laboratory method entails thermal decomposition of mercuric cyanide:

2 Hg(CN)2 → (CN)2 + Hg2(CN)2 Alternatively, one can combine solutions of copper(II) salts (such as copper(II) sulfate) with cyanides, an unstable copper(II) cyanide is formed which rapidly decomposes into copper(I) cyanide and cyanogen.[9]

2 CuSO4 + 4 KCN → (CN)2 + 2 CuCN + 2 K2SO4 Industrially, it is created by the oxidation of hydrogen cyanide, usually using chlorine over an activated silicon dioxide catalyst or nitrogen dioxide over a copper salt. It is also formed when nitrogen and acetylene are reacted by an electrical spark or discharge.[10]

Paracyanogen[edit] Paracyanogen can be best prepared by heating mercuric cyanide. It can also be prepared by heating silver cyanide, silver cyanate, cyanogen iodide or cyanuric iodide.[11] 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).[8] Based on experimental evidence, the structure of this polymeric material is thought to be rather irregular, with most of the carbon atoms being of sp2 type and localized domains of π conjugation.[12] History[edit] Cyanogen was first synthesized in 1815 by Joseph 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, I create), because cyanide was first isolated by the Swedish chemist Carl Wilhelm Scheele from the pigment "Prussian blue".[13] By the 1850s, cyanogen soap was used by photographers to remove silver stains from their hands.[14] It attained importance with the growth of the fertilizer 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 of nitrocellulose. Cyanogen is a highly toxic compound. In 1910 a spectroscopic analysis of Halley'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. Because of the extremely diffuse nature of the tail, there was no effect when the planet passed through it.[15][16]

Safety[edit] Like other cyanides, cyanogen is very toxic, as it readily undergoes reduction to cyanide, which poisons the cytochrome c oxidase complex, thus interrupting the mitochondrial electron 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.[17] Lethal dose through inhalation typically ranges from 100 to 150 milligrams (1.5 to 2.3 grains). Inhalation of 900 ppm over a period of 10 minutes is considered lethal.[18] Cyanogen produces the second-hottest-known natural flame (after carbon subnitride) with a temperature of over 4,525 °C (8,177 °F) when it burns in oxygen.[19][20]

See also[edit] Pseudohalogen References[edit]

^ a b Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 902. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4. 

^ "oxalonitrile (CHEBI:29308)". Chemical Entities of Biological Interest. UK: European Bioinformatics Institute. 27 October 2006. Main. Retrieved 6 June 2012. 

^ a b NIOSH Pocket Guide to Chemical Hazards. Department of Health and Human Services, Centers for Disease Control, National Institute for Occupational Safety & Health. September 2007. p. 82. 

^ a b The Merck Index (10th ed.). Rahway, NJ: Merck & Co. 1983. p. 385. 

^ a b c d e f "NIOSH Pocket Guide to Chemical Hazards #0161". National Institute for Occupational Safety and Health (NIOSH). 

^ Ringer, A. L.; Sherrill, C. D.; King, R. A.; Crawford, T. D. (2008). "Low-lying singlet excited states of isocyanogen". International Journal of Quantum Chemistry. 106 (6): 1137–1140. Bibcode:2008IJQC..108.1137R. doi:10.1002/qua.21586. 

^ Hartman, W. W.; Dreger, E. E. (1931). "Cyanogen Bromide" (PDF). Organic Syntheses. 11: 30. ; Collective Volume, 2, p. 150 

^ a b Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. pp. 320–321. ISBN 0-08-037941-9. 

^ Brotherton, T. K.; Lynn, J. W. (1959). "The Synthesis And Chemistry Of Cyanogen". Chemical Reviews. 59 (5): 841–883. doi:10.1021/cr50029a003. 

^ Breneman, A. A. (January 1889). "The Fixation of Atmospheric Nitrogen". Journal of the American Chemical Society. 11 (1): 2–27. doi:10.1021/ja02126a001. 

^ Bircumshaw, L. L.; F. M. Tayler; D. H. Whiffen (1954). "Paracyanogen: its formation and properties. Part I". J. Chem. Soc.: 931–935. doi:10.1039/JR9540000931. 

^ Maya, Leon (1993). "Paracyanogen Reexamined". Polymer Science: Part A. 31: 2595–2600. 

^ Gay-Lussac, J. L. (1815). "Recherches sur l'acide prussique". Annales de Chimie. 95: 136–231.  Gay-Lussac names cyanogen on p. 163.

^ Crookes, William, ed. (1859). "Photographic News: A Weekly Record of the Process of the Photography": 11–11. 

^ Comet's Poisonous Tail.

^ Halley's Comet 100 years ago.

^ Muir, G. D., ed. (1971). Hazards in the Chemical Laboratory. London: The Royal Institute of Chemistry. 

^ Ledgard, Jared (2006). A Laboratory History of Chemical Warfare Agents. Lulu.com. ISBN 0615136451.  p. 82.

^ Thomas, N.; Gaydon, A. G.; Brewer, L. (1952). "Cyanogen Flames and the Dissociation Energy of N2". The Journal of Chemical Physics. 20 (3): 369–374. Bibcode:1952JChPh..20..369T. doi:10.1063/1.1700426. 

^ J. B. Conway; R. H. Wilson Jr.; A. V. Grosse (1953). "THE TEMPERATURE OF THE CYANOGEN-OXYGEN FLAME". Journal of the American Chemical Society. 75 (2): 499. doi:10.1021/ja01098a517. 

External links[edit]

Wikimedia Commons has media related to cyanogen.

Wikisource has the text of the 1911 Encyclopædia Britannica article Cyanogen. National Pollutant Inventory - Cyanide compounds fact sheet PhysOrg.com CDC - NIOSH Pocket Guide to Chemical Hazards

vteSalts and covalent derivatives of the cyanide ion

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

HCN

He

LiCN

Be(CN)2

B

C

NH4CN

OCN−,-NCO

FCN

Ne

NaCN

Mg(CN)2

Al(CN)3

Si(CN)4,Me3SiCN

P(CN)3

SCN−,-NCS,(SCN)2,S(CN)2

ClCN

Ar

KCN

Ca(CN)2

Sc(CN)3

Ti(CN)4

V

Cr(CN)64− Cr(CN)63−

Mn(CN)2

Fe(CN)3,Fe(CN)64−,Fe(CN)63−

Co(CN)2, Co(CN)3

Ni(CN)2Ni(CN)42−

CuCN

Zn(CN)2

Ga(CN)3

Ge

As(CN)3

SeCN−(SeCN)2Se(CN)2

BrCN

Kr

RbCN

Sr(CN)2

Y(CN)3

Zr(CN)4

Nb

Mo(CN)84−

Tc

Ru(CN)63−

Rh(CN)63−

Pd(CN)2

AgCN

Cd(CN)2

In(CN)3

Sn

Sb(CN)3

Te

ICN

Xe

CsCN

Ba(CN)2

 

Hf

Ta

W(CN)84−

Re

Os(CN)63−

Ir(CN)63−

Pt(CN)42-, Pt(CN)64-

AuCN,Au(CN)2−

Hg2(CN)2, Hg(CN)2

TlCN

Pb(CN)2

Bi(CN)3

Po

At

Rn

Fr

Ra

 

Rf

Db

Sg

Bh

Hs

Mt

Ds

Rg

Cn

Nh

Fl

Mc

Lv

Ts

Og

La

Ce(CN)3, Ce(CN)4

Pr

Nd

Pm

Sm

Eu

Gd(CN)3

Tb

Dy

Ho

Er

Tm

Yb

Lu

Ac

Th

Pa

UO2(CN)2

Np

Pu

Am

Cm

Bk

Cf

Es

Fm

Md

No

Lr

vteNitrogen species Hydrides: NH3 NH4+ NH2− MNH2 N3− NH2OH N2H4 N3– Organic: -NH2 -CHR=NHR -CONHR2 HCN CN− C2N2 H2NCN CH2N2 Oxides: N2O NO NO2 N2O3 N2O4 N2O5 HNO2 HNO3 NO2− NO3− NO+ NO2+ Halides: NF3 NCl3 NBr3 NI3 FN3 ClN3 NH2Cl Chemical formulas vteMolecules detected in outer spaceMoleculesDiatomic Aluminium monochloride Aluminium monofluoride Aluminium monoxide Argonium Carbon monophosphide Carbon monosulfide Carbon monoxide Carborundum Cyanogen radical Diatomic carbon Fluoromethylidynium Hydrogen chloride Hydrogen fluoride Hydrogen (molecular) Hydroxyl radical Iron(II) oxide Magnesium monohydride cation Methylidyne radical Nitric oxide Nitrogen (molecular) Nitrogen monohydride Nitrogen sulfide Oxygen (molecular) Phosphorus monoxide Phosphorus mononitride Potassium chloride Silicon carbide Silicon mononitride Silicon monoxide Silicon monosulfide Sodium chloride Sodium iodide Sulfur monohydride Sulfur monoxide Titanium oxide Triatomic Aluminium hydroxide Aluminium isocyanide Amino radical Carbon dioxide Carbonyl sulfide CCP radical Chloronium Diazenylium Dicarbon monoxide Disilicon carbide Ethynyl radical Formyl radical Hydrogen cyanide (HCN) Hydrogen isocyanide (HNC) Hydrogen sulfide Hydroperoxyl Iron cyanide Isoformyl Magnesium cyanide Magnesium isocyanide Methylene radical N2H+ Nitrous oxide Nitroxyl Ozone Phosphaethyne Potassium cyanide Protonated molecular hydrogen Sodium cyanide Sodium hydroxide Silicon carbonitride c-Silicon dicarbide SiNC Sulfur dioxide Thioformyl Thioxoethenylidene Titanium dioxide Tricarbon Water Fouratoms Acetylene Ammonia Cyanic acid Cyanoethynyl Cyclopropynylidyne Formaldehyde Fulminic acid HCCN Hydrogen peroxide Hydromagnesium isocyanide Isocyanic acid Isothiocyanic acid Ketenyl Methylene amidogen Methyl radical Propynylidyne Protonated carbon dioxide Protonated hydrogen cyanide Silicon tricarbide Thioformaldehyde Tricarbon monoxide Tricarbon sulfide Thiocyanic acid Fiveatoms Ammonium ion Butadiynyl Carbodiimide Cyanamide Cyanoacetylene Cyanoformaldehyde Cyanomethyl Cyclopropenylidene Formic acid Isocyanoacetylene Ketene Methane Methoxy radical Methylenimine Propadienylidene Protonated formaldehyde Protonated formaldehyde Silane Silicon-carbide cluster Sixatoms Acetonitrile Cyanobutadiynyl radical E-Cyanomethanimine Cyclopropenone Diacetylene Ethylene Formamide HC4N Ketenimine Methanethiol Methanol Methyl isocyanide Pentynylidyne Propynal Protonated cyanoacetylene Sevenatoms Acetaldehyde Acrylonitrile Vinyl cyanide Cyanodiacetylene Ethylene oxide Hexatriynyl radical Methylacetylene Methylamine Methyl isocyanate Vinyl alcohol Eightatoms Acetic acid Aminoacetonitrile Cyanoallene Ethanimine Glycolaldehyde Heptatrienyl radical Hexapentaenylidene Methylcyanoacetylene Methyl formate Propenal Nineatoms Acetamide Cyanohexatriyne Cyanotriacetylene Dimethyl ether Ethanol Methyldiacetylene Octatetraynyl radical Propene Propionitrile Tenatomsor more Acetone Benzene Benzonitrile Buckminsterfullerene (C60 fullerene, buckyball) C70 fullerene Cyanodecapentayne Cyanopentaacetylene Cyanotetra-acetylene Ethylene glycol Ethyl formate Methyl acetate Methyl-cyano-diacetylene Methyltriacetylene Propanal n-Propyl cyanide Pyrimidine Deuteratedmolecules Ammonia Ammonium ion Formaldehyde Formyl radical Heavy water Hydrogen cyanide Hydrogen deuteride Hydrogen isocyanide Methylacetylene N2D+ Trihydrogen cation Unconfirmed Anthracene Dihydroxyacetone Ethyl methyl ether Glycine Graphene H2NCO+ Linear C5 Naphthalene cation Phosphine Pyrene Silylidine Related Abiogenesis Astrobiology Astrochemistry Atomic and molecular astrophysics Chemical formula Circumstellar envelope Cosmic dust Cosmic ray Cosmochemistry Diffuse interstellar band Earliest known life forms Extraterrestrial life Extraterrestrial liquid water Forbidden mechanism Helium hydride ion Homochirality Intergalactic dust Interplanetary medium Interstellar medium Photodissociation region Iron–sulfur world theory Kerogen Molecules in stars Nexus for Exoplanet System Science Organic compound Outer space PAH world hypothesis Panspermia Polycyclic aromatic hydrocarbon (PAH) RNA world hypothesis Spectroscopy Tholin

Category:Astrochemistry Portal:Astrobiology

Authority control GN