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Cyano radical

Names
Preferred IUPAC name Nitridocarbon
Other names Cyanyl Nitrile Cyano Isocyano Azanylidynemethyl
Identifiers
CAS Number	2074-87-5
3D model (JSmol)	Interactive image
Beilstein Reference	1697323
ChEBI	CHEBI:29306
ChemSpider	4514240
Gmelin Reference	88
PubChem CID	5359238
InChI InChI=1S/CN/c1-2Key: JEVCWSUVFOYBFI-UHFFFAOYSA-N
SMILES #N
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). Y verify (what is  ?) Infobox references

The cyano radical (or cyanido radical) is a radical with molecular formula CN, sometimes written CN. The cyano radical was one of the first detected molecules in the interstellar medium, in 1938. Its detection and analysis was influential in astrochemistry. The discovery was confirmed with a coudé spectrograph, which was made famous and credible due to this detection. ·CN has been observed in both diffuse clouds and dense clouds. Usually, CN is detected in regions with hydrogen cyanide, hydrogen isocyanide, and HCNH, since it is involved in the creation and destruction of these species (see also Cyanogen).

Physical properties

Bonding in the cyano radical can be described as a combination of two resonance structures: the structure with the unpaired electron on the carbon is the minor contributor, while the structure with the unpaired electron on the nitrogen (the isocyano radical) is the major contributor. The charge separation in the isocyano radical is similar to that of carbon monoxide. CN has a dipole moment of 1.45 debyes and a Σ ground electronic state. The selection rules are:

${\displaystyle {\begin{aligned}N+S&=J\\J+I&=F\end{aligned}}}$

where N is the angular momentum, S is the electric spin, and I = 1 is the nuclear spin of N.

Formation and destruction of CN

Formation

• Dissociative recombination in diffuse clouds:

  HCN + e → CN + H

• Photodissociation in dense clouds:

  HCN + hν → CN + H

Destruction

H
₃ + CN → HCN + H₂

Detections of CN

A spectral line of CN was detected in 1938 in the interstellar medium in the ultraviolet, and was identified in 1940 by Andrew McKellar. The coudé spectrograph and a 100-inch (2.5 m) telescope were used to observe CN's interstellar lines and ultraviolet spectra. Use of the spectrograph confirmed McKellar's findings and also made the spectrograph famous. In 1970, CN's first rotational transition from J = 0 to J = 1 was detected In the Orion Nebula and the W51 nebula. The first detection of CN in extragalactic sources were seen toward Sculptor Galaxy (NGC 253), IC 342, and M82 In 1988. These emission lines seen were from N = 1 to N = 0 and N = 2 to N = 1. In 1991, the CN vibration-rotational bands were observed in a king furnace at the National Solar Observatory using a McMath Fourier-Transform spectrometer. The observed 2 to 0 lines show an extreme hyperfine structure. In 1995, the rotational absorption spectrum of ·CN in the ground state was observed in the 1 THz region, and most of the lines were measured in the range of 560 to 1020 GHz. Four new rotational transitions were measured; N = 8 to N = 8, J = ⁠15/2⁠ to J = ⁠17/2⁠ and J = ⁠17/2⁠ to J = ⁠19/2⁠; N = 7 to N = 8, J = ⁠15/2⁠ to J = ⁠17/2⁠ and J = ⁠13/2⁠ to J = ⁠15/2⁠.

References

1. ^ Liszt, H.; Lucas, R. (2001). "Comparative chemistry of diffuse clouds: II. CN, HCN, HNC, CH₃CN & N₂H". Astronomy & Astrophysics. 370 (2): 576–585. arXiv:astro-ph/0103247. Bibcode:2001A&A...370..576L. doi:10.1051/0004-6361:20010260.
2. Skatrud, David D.; De Lucia, Frank C.; Blake, Geoffrey A.; Sastry, K. V. L. N. (1983). "The millimeter and submillimeter spectrum of CN in its first four vibrational states". Journal of Molecular Spectroscopy. 99 (1): 35–46. Bibcode:1983JMoSp..99...35S. doi:10.1016/0022-2852(83)90290-4.
3. Bakker, Eric J.; Waters, L. B. F. M.; Lamers, Henry J. G. L. M.; Trams, Norman R.; Van der Wolf, Frank L. A. (1996). "Detection of C₂, CN, and NaI D absorption in the AGB remnant of HD 56126". Astronomy and Astrophysics. 310: 893–907. arXiv:astro-ph/9510122. Bibcode:1996A&A...310..893B.
4. McKellar, Andrew (1940). "Evidence for the molecular origin of some hitherto unidentified interstellar lines". Publications of the Astronomical Society of the Pacific. 52 (307): 187–192. Bibcode:1940PASP...52..187M. doi:10.1086/125159.
5. Adams, Walter S. (1941). "Some results with the coudé spectrograph of the Mount Wilson Observatory". The Astrophysical Journal. 93: 11–23. Bibcode:1941ApJ....93...11A. doi:10.1086/144237.
6. ^ Jefferts, K. B.; Penzias, A. A.; Wilson, R. W. (1970). "Observation of the CN radical in the Orion Nebula and W51". The Astrophysical Journal. 161 (2): L87–L89. Bibcode:1970ApJ...161L..87J. doi:10.1086/180576.
7. Henkel, C.; Mauersberger, R.; Schilke, P. (1988). "Molecules in external galaxies: The detection of CN, C₂H, and HNC, and the tentative detection of HC₃N". Astronomy and Astrophysics. 201: L23–L26. Bibcode:1988A&A...201L..23H.
8. Klisch, E.; Klaus, Th.; Belov, S. P.; Winnewisser, G.; Herbst, E. (1995). "Laboratory rotational spectrum of CN in the 1 THz region". Astronomy and Astrophysics. 304: L5–L8. Bibcode:1995A&A...304L...5K.

v t e Molecules detected in outer space
Molecules	Diatomic Aluminium monochloride Aluminium monofluoride Aluminium(II) oxide Argonium Carbon cation Carbon monophosphide Carbon monosulfide Carbon monoxide Cyano radical Diatomic carbon Fluoromethylidynium Helium hydride ion Hydrogen chloride Hydrogen fluoride Hydrogen (molecular) Hydroxyl radical Iron(II) oxide Magnesium monohydride Methylidyne radical Nitric oxide Nitrogen (molecular) Imidogen Sulfur mononitride Oxygen (molecular) Phosphorus monoxide Phosphorus mononitride Potassium chloride Silicon carbide Silicon monoxide Silicon monosulfide Sodium chloride Sodium iodide Sulfanyl Sulfur monoxide Titanium(II) oxide Triatomic Aluminium(I) 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 N2H Nitrous oxide Nitroxyl Ozone Methylidynephosphane Potassium cyanide Trihydrogen cation Sodium cyanide Sodium hydroxide Silicon carbonitride c-Silicon dicarbide SiNC Sulfur dioxide Thioformyl Thioxoethenylidene Titanium dioxide Tricarbon Water Four atoms Acetylene Ammonia Isocyanic acid Cyanoethynyl Formaldehyde Fulminic acid HCCN Hydrogen peroxide Hydromagnesium isocyanide Isocyanic acid Isothiocyanic acid Ketenyl Methylene amidogen Methyl cation Methyl radical Propynylidyne Protonated carbon dioxide Protonated hydrogen cyanide Silicon tricarbide Thioformaldehyde Tricarbon monoxide Tricarbon monosulfide Thiocyanic acid Five atoms Ammonium ion Butadiynyl Carbodiimide Cyanamide Cyanoacetylene Cyanoformaldehyde Cyanomethyl Cyclopropenylidene Formic acid Isocyanoacetylene Ketene Methane Methoxy radical Methylenimine Propadienylidene Protonated formaldehyde Silane Silicon-carbide cluster Six atoms Acetonitrile Cyanobutadiynyl radical E-Cyanomethanimine Cyclopropenone Diacetylene Ethylene Formamide HC4N Ketenimine Methanethiol Methanol Methyl isocyanide Pentynylidyne Propynal Protonated cyanoacetylene Seven atoms Acetaldehyde Acrylonitrile Vinyl cyanide Cyanodiacetylene Ethylene oxide Glycolonitrile Hexatriynyl radical Propyne Methylamine Methyl isocyanate Vinyl alcohol Eight atoms Acetic acid Aminoacetonitrile Cyanoallene Ethanimine Glycolaldehyde Hexapentaenylidene Methylcyanoacetylene Methyl formate Acrolein Nine atoms Acetamide Cyanohexatriyne Dimethyl ether Ethanol Methyldiacetylene Octatetraynyl radical Propene Ethanethiol Propionitrile N-Methylformamide Ten atoms or more Acetone Benzene Benzonitrile Buckminsterfullerene (C60, C60, fullerene, buckyball) C70 fullerene Cyanodecapentayne Ethylene glycol Ethyl formate Methyl acetate Methyl-cyano-diacetylene Methyltriacetylene Propionaldehyde Butyronitrile Pyrimidine Heptatrienyl radical
Deuterated molecules	Ammonia Ammonium ion Formaldehyde Formyl radical Heavy water Hydrogen cyanide Hydrogen deuteride Hydrogen isocyanide Propyne N2D Trihydrogen cation
Unconfirmed	Anthracene Dihydroxyacetone Methoxyethane Glycine Graphene Hemolithin H2NCO Linear C5 Naphthalene cation Phosphine Pyrene Silylidyne
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• Cyanides