Methenium
| |
| Names | |
|---|---|
| Preferred IUPAC name
Methylium[1] | |
| Other names
Methyl cation; Carbanylium
| |
| Identifiers | |
3D model (JSmol)
|
|
| 1839325 | |
| ChEBI | |
| ChemSpider | |
| 48893 | |
PubChemCID
|
|
| UNII | |
CompTox Dashboard(EPA)
|
|
| |
| |
| Properties | |
| CH3+ | |
| Molar mass | 15.034g·mol−1 |
| Related compounds | |
Relatedisoelectronic
|
borane |
Except where otherwise noted, data are given for materials in theirstandard state(at 25 °C [77 °F], 100 kPa).
| |
Inorganic chemistry,methenium(also calledmethylium,carbenium,[2]methyl cation,orprotonated methylene) is acationwith the formulaCH+
3.It can be viewed as amethylene radical(:CH
2) with an addedproton(H+
), or as amethyl radical(•CH
3) with oneelectronremoved. It is acarbocationand anenium ion,making it the simplest of thecarbenium ions.[3]
Structure
[edit]Experiments and calculations generally agree that the methenium ion is planar, with threefoldsymmetry.[3]The carbon atom is a prototypical (and exact) example of sp2hybridization.
Preparation and reactions
[edit]Formass spectrometrystudies at low pressure, methenium can be obtained byultravioletphotoionizationof methyl radical,[3]or by collisions of monatomic cations such asC+
andKr+
with neutral methane.[4]In such conditions, it will react withacetonitrileCH
3CNto form the ion(CH
3)
2CN+
.[5]
Upon capture of a low-energy electron (less than1eV), it will spontaneously dissociate.[6]
It is seldom encountered as an intermediate in the condensed phase. It is proposed as a reactive intermediate that forms upon protonation or hydride abstraction of methane withFSO3H-SbF5.The methenium ion is very reactive, even towardsalkanes.[7]
Detection
[edit]Origins of life
[edit]In June 2023, astronomersdetected,for the first time outside the Solar System, methyl cation, CH3+(and/orcarbon cation,C+), the known basic ingredients oflife,ininterstellar space.[8][9]
See also
[edit]References
[edit]- ^International Union of Pure and Applied Chemistry(2014).Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013.The Royal Society of Chemistry.p. 1089.doi:10.1039/9781849733069.ISBN978-0-85404-182-4.
- ^"Ions, Free Radicals, and Radical-Ion",Nomenclature of Organic Compounds,Advances in Chemistry, vol. 126, AMERICAN CHEMICAL SOCIETY, June 1974, pp. 216–224,doi:10.1021/ba-1974-0126.ch028,ISBN978-0841201910
- ^abcGolob, L.; Jonathan, N.; Morris, A.; Okuda, M.; Ross, K.J. (1972). "The first ionization potential of the methyl radical as determined by photoelectron spectroscopy".Journal of Electron Spectroscopy and Related Phenomena.1(5). Elsevier BV: 506–508.doi:10.1016/0368-2048(72)80022-7.ISSN0368-2048.
- ^Sharma, R. B.; Semo, N. M.; Koski, W. S. (1987). "Dynamics of the reactions of methylium, methylene radical cation, and methyliumylidene with acetylene".The Journal of Physical Chemistry.91(15). American Chemical Society (ACS): 4127–4131.doi:10.1021/j100299a037.ISSN0022-3654.
- ^McEwan, Murray J.; Denison, Arthur B.; Huntress, Wesley T.; Anicich, Vincent G.; Snodgrass, J.; Bowers, M. T. (1989). "Association reactions at low pressure. 2. The methylium/methyl cyanide system".The Journal of Physical Chemistry.93(10). American Chemical Society (ACS): 4064–4068.doi:10.1021/j100347a039.ISSN0022-3654.
- ^Bahati, E. M.; Fogle, M.; Vane, C. R.; Bannister, M. E.; Thomas, R. D.; Zhaunerchyk, V. (2009-05-11). "Electron-impact dissociation ofCD+
3andCH+
3ions producingCD+
2,CH+
andC+
fragment ions ".Physical Review A.79(5). American Physical Society (APS): 052703.doi:10.1103/physreva.79.052703.ISSN1050-2947. - ^Hogeveen, H.; Lukas, J.; Roobeek, C. F. (1969). "Trapping of the methyl cation by carbon monoxide; formation of acetic acid from methane".Journal of the Chemical Society D: Chemical Communications(16): 920.doi:10.1039/c29690000920.ISSN0577-6171.
- ^Sauers, Elisha (27 June 2023)."Webb telescope just found something unprecedented in the Orion Nebula - Astronomers are excited about the detection of a special molecule in space".Mashable.Archivedfrom the original on 27 June 2023.Retrieved27 June2023.
- ^Berné, Olivier; et al. (26 June 2023)."Formation of the Methyl Cation by Photochemistry in a Protoplanetary Disk".Nature.621(7977): 56–59.arXiv:2401.03296.doi:10.1038/s41586-023-06307-x.hdl:1887/3716674.PMID37364766.S2CID259260435.Archivedfrom the original on 27 June 2023.Retrieved27 June2023.
