甲烯𬭩离子

甲烯𬭩离子
	IUPAC名; Methylium
别名	Methyl cation; Carbanylium
识别
CAS号	14531-53-4
PubChem	644094
SMILES	[CH3+];
InChI	1S/CH3/h1H3/q+1;
InChIKey	UHDUIDUEUEQND-UHFFFAOYSA-N
ChEBI	29437
性质
化学式	CH3
摩尔质量	15.03 g·mol−1
相关物质
相关等离子化合物	甲硼烷
	若非注明，所有数据均出自标准状态（25 ℃，100 kPa）下。

在有机化学中，甲烯𬭩离子（又称质子化亚甲基）是一种阳离子，化学式为CH+
3。它可以视作一个亚甲基自由基（:CH
2）加上一个质子（H+
），或一个甲基自由基（英语：methyl radical）（•CH
3）去除一个电子。它是碳正离子和烯𬭩离子（英语：enium ion），是最简单的烯𬭩离子（英语：enium ion）。^[2]

结构

实验和计算普遍表示，甲烯𬭩离子具有平面结构和三重对称性。^[2]离子的碳原子是sp²杂化的原型（和精确）示例。

制备和反应

对于低压的质谱研究，甲烯𬭩离子可以通过甲基自由基的紫外线光电离，^[2]或将中性甲烷与单原子阳离子（如C+
和Kr+
）碰撞制备。^[3]在这种条件下，它会与乙腈CH
3CN反应，形成离子(CH
3)
2CN+
。^[4]

捕获低能电子后（小于6981160217648700000♠1 eV），它会自发地解离。^[5]

它很少在凝聚相下以中间体的形式出现。它被提议为一种反应性中间体，在甲烷与FSO₃H-SbF₅进行质子化或氢化物提取时形成。甲𬭩离子非常活泼，对烷烃也是如此。^[6]

参见

参考文献

^ International Union of Pure and Applied Chemistry. Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013. The Royal Society of Chemistry. 2014: 1089. ISBN 978-0-85404-182-4. doi:10.1039/9781849733069.
^ ^2.0 ^2.1 ^2.2 L. Golob, N. Jonathan, A. Morris, M. Okuda, K.J. Ross (1972), "The first ionization potential of the methyl radical as determined by photoelectron spectroscopy". Journal of Electron Spectroscopy and Related Phenomena, volume 1, issue 5, pp. 506–508 doi:10.1016/0368-2048(72)80022-7
^ R.B. Sharma, N.M. Semo, W.S. Koski (1987), "Dynamics of the reactions of methylium, methylene radical cation, and methyliumylidene with acetylene". Journal of Physical Chemistry, volume 91, issue 15, pp. 4127–4131 doi:10.1021/j100299a037
^ Murray J. McEwan, Arthur B. Denison, Wesley T. Huntress Jr., Vincent G. Anicich, J. Snodgrass, M.T. Bowers (1989), "Association reactions at low pressure. 2. The methylium/methyl cyanide system". Journal of Physical Chemistry, volume 93, issue 10, pp. 4064–4068. doi:10.1021/j100347a039
^ E.M. Bahati, M. Fogle, C.R. Vane, M.E. Bannister, R.D. Thomas and V. Zhaunerchyk (2009), "Electron-impact dissociation of CD+
3 and CH+
3 ions producing CD+
2, CH+
and C+
fragment ions". Physical Review, volume 79, article 052703 doi:10.1103/PhysRevA.79.052703
^ Hogeveen, H.; Lukas, J.; Roobeek, C. F. Trapping of the methyl cation by carbon monoxide; formation of acetic acid from methane. Journal of the Chemical Society D: Chemical Communications. 1969, (16): 920. ISSN 0577-6171. doi:10.1039/c29690000920 （英语）.

[1] International Union of Pure and Applied Chemistry. Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013. The Royal Society of Chemistry. 2014: 1089. ISBN 978-0-85404-182-4. doi:10.1039/9781849733069.

[Golob-2] 2.0 ^2.1 ^2.2 L. Golob, N. Jonathan, A. Morris, M. Okuda, K.J. Ross (1972), "The first ionization potential of the methyl radical as determined by photoelectron spectroscopy". Journal of Electron Spectroscopy and Related Phenomena, volume 1, issue 5, pp. 506–508 doi:10.1016/0368-2048(72)80022-7

[Sharma-3] R.B. Sharma, N.M. Semo, W.S. Koski (1987), "Dynamics of the reactions of methylium, methylene radical cation, and methyliumylidene with acetylene". Journal of Physical Chemistry, volume 91, issue 15, pp. 4127–4131 doi:10.1021/j100299a037

[McEwan-4] Murray J. McEwan, Arthur B. Denison, Wesley T. Huntress Jr., Vincent G. Anicich, J. Snodgrass, M.T. Bowers (1989), "Association reactions at low pressure. 2. The methylium/methyl cyanide system". Journal of Physical Chemistry, volume 93, issue 10, pp. 4064–4068. doi:10.1021/j100347a039

[Bahati-5] E.M. Bahati, M. Fogle, C.R. Vane, M.E. Bannister, R.D. Thomas and V. Zhaunerchyk (2009), "Electron-impact dissociation of CD+
3 and CH+
3 ions producing CD+
2, CH+
and C+
fragment ions". Physical Review, volume 79, article 052703 doi:10.1103/PhysRevA.79.052703

[6] Hogeveen, H.; Lukas, J.; Roobeek, C. F. Trapping of the methyl cation by carbon monoxide; formation of acetic acid from methane. Journal of the Chemical Society D: Chemical Communications. 1969, (16): 920. ISSN 0577-6171. doi:10.1039/c29690000920 （英语）.

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