Chemistry:Methenium
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| Names | |
|---|---|
| Preferred IUPAC name
Methylium[1] | |
| Other names
Methyl cation; Carbanylium
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| Identifiers | |
3D model (JSmol)
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| 1839325 | |
| ChEBI | |
| ChemSpider | |
| 48893 | |
PubChem CID
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| UNII | |
CompTox Dashboard (EPA)
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| Properties | |
| CH3+ | |
| Molar mass | 15.034 g·mol−1 |
| Related compounds | |
Related isoelectronic
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borane |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
In organic chemistry, methenium (also called methylium, carbenium,[2] methyl cation, or protonated methylene) is a cation with the formula CH+3. It can be viewed as a methylene radical (:CH2) with an added proton (H+), or as a methyl radical (•CH3) with one electron removed. It is a carbocation and an enium ion, making it the simplest of the carbenium ions.[3]
Structure
Experiments and calculations generally agree that the methenium ion is planar, with threefold symmetry.[3] The carbon atom is a prototypical (and exact) example of sp2 hybridization.
Preparation and reactions
For mass spectrometry studies at low pressure, methenium can be obtained by ultraviolet photoionization of methyl radical,[3] or by collisions of monatomic cations such as C+ and Kr+ with neutral methane.[4] In such conditions, it will react with acetonitrile CH3CN to form the ion (CH3)2CN+.[5]
Upon capture of a low-energy electron (less than 1 eV), 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 with FSO3H-SbF5. The methenium ion is very reactive, even towards alkanes.[7]
Detection
Origins of life
In June 2023, astronomers detected, for the first time outside the Solar System, methyl cation, CH3+ (and/or carbon cation, C+), the known basic ingredients of life, in interstellar space.[8][9]
See also
References
- ↑ International Union of Pure and Applied Chemistry (2014). Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013. The Royal Society of Chemistry. pp. 1089. doi:10.1039/9781849733069. ISBN 978-0-85404-182-4.
- ↑ "Ions, Free Radicals, and Radical-Ion" (in EN), Nomenclature of Organic Compounds, Advances in Chemistry, 126, AMERICAN CHEMICAL SOCIETY, June 1974, pp. 216–224, doi:10.1021/ba-1974-0126.ch028, ISBN 978-0841201910, https://archive.org/details/nomenclatureofor0000flet/page/216
- ↑ 3.0 3.1 3.2 Golob, 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 (Elsevier BV) 1 (5): 506–508. doi:10.1016/0368-2048(72)80022-7. ISSN 0368-2048.
- ↑ 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 (American Chemical Society (ACS)) 91 (15): 4127–4131. doi:10.1021/j100299a037. ISSN 0022-3654.
- ↑ 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 (American Chemical Society (ACS)) 93 (10): 4064–4068. doi:10.1021/j100347a039. ISSN 0022-3654.
- ↑ Bahati, E. M.; Fogle, M.; Vane, C. R.; Bannister, M. E.; Thomas, R. D.; Zhaunerchyk, V. (2009-05-11). "Electron-impact dissociation of CD+3 and CH+3 ions producing CD+2, CH+ and C+ fragment ions". Physical Review A (American Physical Society (APS)) 79 (5): 052703. doi:10.1103/physreva.79.052703. ISSN 1050-2947.
- ↑ Hogeveen, H.; Lukas, J.; Roobeek, C. F. (1969). "Trapping of the methyl cation by carbon monoxide; formation of acetic acid from methane" (in en). Journal of the Chemical Society D: Chemical Communications (16): 920. doi:10.1039/c29690000920. ISSN 0577-6171.
- ↑ 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. Archived from the original on 27 June 2023. https://archive.today/20230627153343/https://mashable.com/article/james-webb-space-telescope-orion-nebula. Retrieved 27 June 2023.
- ↑ Berne, Olivier (26 June 2023). "Formation of the Methyl Cation by Photochemistry in a Protoplanetary Disk". Nature: 1–3. doi:10.1038/s41586-023-06307-x. PMID 37364766. Archived from the original on 27 June 2023. https://archive.today/20230627160651/https://doi.org/10.1038/s41586-023-06307. Retrieved 27 June 2023.
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