Carbonium ion
In chemistry, carbonium ion is any cation that has a pentavalent carbon atom,[1][2] The name carbonium may also be used for the simplest member of the class, properly called methanium (CH+
5), where the five valences are filled with hydrogen atoms.[3]
The next simplest carbonium ions after methanium have two carbons. Ethanium or protonated acetylene C
2H+
3 and ethenium H are usually classified in other families. The ethanium ion C
2H+
7 has been studied as an extremely rarefied gas by infrared spectroscopy.[4]
In older literature the name "carbonium ion" was used for what is today called carbenium. The current definitions were proposed by the chemist George Andrew Olah in 1972.[1] and are now widely accepted.
A stable carbonium ion is the complex penta(triphenylphosphine gold(I))methanium (Ph
3PAu)
5C+
, produced by Schmidbauer and others.[5]
Preparation
Carbonium ions can be obtained by treating alkanes with very strong acids.[6] Industrially, they are formed in the refining of petroleum during primary thermal cracking.[7]
See also
- More carbonium ions called non-classical ions are found in certain norbornyl systems
- Onium compounds
- Carbenium ion
References
- ↑ 1.0 1.1 Lua error in package.lua at line 80: module 'strict' not found.
- ↑ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "Carbonium ion".
- ↑ Doo Wan Boo and Yuan T. Lee (1995), "Infrared spectroscopy of the molecular hydrogen solvated carbonium ions, CH+
5(H
2)n (n=1–6)". J. Chem. Phys. volume 103, page 520; doi:10.1063/1.470138 - ↑ L. I. Yeh, J. M. Price, and Y. T. Lee (1989), "Infrared spectroscopy of the pentacoordinated carbonium ion C
2H+
7". Journal of the American Chemical Society, volume 111, pages 5591-5604. doi:10.1021/ja00197a015 - ↑ George A. Olah (1998), "Onium Ions". John Wiley & Sons, 509 pages. ISBN 9780471148777
- ↑ J. Sommer and R. Jost (2000), "Carbenium and carbonium ions in liquid- and solid-superacid-catalyzed activation of small alkanes". Pure and Applied Chemistry, volume 72, pages 2309–2318. doi:10.1351/pac200072122309
- ↑ Office of Energy Efficiency and Renewable Energy, U.S. DOE (2006). "Energy Bandwidth for Petroleum Refining Processes"
