Hexatriynyl radical

Hexatriynyl radical
Names

Preferred IUPAC name Hexa-1,3,5-triyn-1-yl
Identifiers
3D model (JSmol)	Interactive image
ChemSpider	10809203^Y
PubChem CID	57417315
InChI InChI=1S/C6H/c1-3-5-6-4-2/h1H^Y Key: MGBKUZLTRVWILP-UHFFFAOYSA-N^Y InChI=1S/C6H/c1-3-5-6-4-2/h1H Key: MGBKUZLTRVWILP-UHFFFAOYSA-N InChI=1/C6H/c1-3-5-6-4-2/h1H Key: MGBKUZLTRVWILP-UHFFFAOYAP
SMILES C#CC#CC#[C]
Properties
Chemical formula	C₆H
Molar mass	73.074 g·mol⁻¹
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is ^YN ?) Infobox references

The hexatriynyl radical, C₆H, is an organic radical molecule consisting of a linear chain of six carbon atoms terminated by a hydrogen (H−C≡C−C≡C−C≡C•). The unpaired electron is located at the opposite end to the hydrogen atom, as indicated. Both experimental work and computer simulations on this species was done in the early 1990s.^[1]^[2]

Synthesis of the radical

The radical can be synthesized by photolysis. Two different examples involve

Argon gas and buta-1,3-diene in a mole ratio of 1500:1
Argon gas and acetylene in a mole ratio of 100:1

Hexatriyne anion

In 2006 the negatively charged hexatriyne anion of this molecule, C₆H⁻, was the first negatively charged ion to be discovered to exist in the interstellar medium, using the Green Bank Telescope.^[3] Negative ions were thought to be unstable in this environment due to the prevalence of ultraviolet light, which dislodges extra electrons such as this.

Synthesis of the anion

The laboratory synthesis starts from acetylene C₂H₂. The reaction takes place within a DC discharge at reduced pressure in a mixture with 15% argon. The product is observed by millimeter-wave spectroscopy.

Analogous species

The two species C₄H⁻ and C₈H⁻ have also been detected.

References

^ Doyle, T.J.; L.N. Shen; C.M.L. Rittby; W.R.M. Graham (November 1, 1991). "A C≡C stretching vibration of the C₆H (hexatriynyl) radical in Ar at 10 K". Journal of Chemical Physics. 95 (9): 6224–6228. Bibcode:1991JChPh..95.6224D. doi:10.1063/1.461568.
^ Liu, R.; X. Zhou; P. Pulay (July 15, 1992). "Ab initio study of the geometry, stretching, vibrations, and assignment of the observed frequencies of the ground state C₆H (hexatriynyl) radical". Journal of Chemical Physics. 97 (2): 1602–1605. Bibcode:1992JChPh..97.1602L. doi:10.1063/1.463236.
^ McCarthy, M. C.; C. A. Gottlieb; H. Gupta; P. Thaddeus (December 1, 2006). "Laboratory and Astronomical Identification of the Negative Molecular Ion C₆H⁻". The Astrophysical Journal. 652 (2): L141–L144. Bibcode:2006ApJ...652L.141M. doi:10.1086/510238.

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 Sulfur monohydride 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 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
Four atoms	Acetylene Ammonia Cyanic 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 HC<sub>4</sub>N Ketenimine Methanethiol Methanol Methyl isocyanide Pentynylidyne Propynal Protonated cyanoacetylene
Seven atoms	Acetaldehyde Acrylonitrile Vinyl cyanide Cyanodiacetylene Ethylene oxide Glycolonitrile Hexatriynyl radical Methylacetylene Methylamine Methyl isocyanate Vinyl alcohol
Eight atoms	Acetic acid Aminoacetonitrile Cyanoallene Ethanimine Glycolaldehyde Hexapentaenylidene Methylcyanoacetylene Methyl formate Propenal
Nine atoms	Acetamide Cyanohexatriyne Cyanotriacetylene Dimethyl ether Ethanol Methyldiacetylene Octatetraynyl radical Propene Propionitrile
Ten atoms or more	Acetone Benzene Benzonitrile Buckminsterfullerene (C₆₀, C₆₀⁺, fullerene, buckyball) C₇₀ fullerene Cyanodecapentayne Cyanopentaacetylene Cyanotetra-acetylene Ethylene glycol Ethyl formate Methyl acetate Methyl-cyano-diacetylene Methyltriacetylene Propanal n-Propyl cyanide Pyrimidine Heptatrienyl radical