Carbonium ion

Not to be confused with Carbenium ion.
Structure of the 2-norbornyl cation based on X-ray crystallography. All other C-C bond lengths are normal (ca. 1.5 Å).[1]

In chemistry, a carbonium ion is a cation that has a pentacoordinated carbon atom.[2] They are a type of carbocation. In older literature, the name "carbonium ion" was used for what is today called carbenium. Carbonium ions charge is delocalized in three-center, two-electron bonds. The more stable members are often bi- or polycyclic.[3]

  1. ^ Scholz, F.; Himmel, D.; Heinemann, F. W.; Schleyer, P. v R.; Meyer, K.; Krossing, I. (2013-07-05). "Crystal Structure Determination of the Nonclassical 2-Norbornyl Cation". Science. 341 (6141): 62–64. Bibcode:2013Sci...341...62S. doi:10.1126/science.1238849. ISSN 0036-8075. PMID 23828938. S2CID 206549219.
  2. ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "Carbonium ion". doi:10.1351/goldbook.C00839
  3. ^ Thomas H. Lowery; Kathleen Schueller Richardson (1981). Mechanism and Theory in Organic Chemistry, Second Edition. Harper and Rowe. p. 396. ISBN 0-06-044083-X.