Carbocations derived from
alkanes by
C-hydronation containing at least one pentacoordinate carbon atom, E.g.
+CH5
methanium,
[C2H7]+
ethanium.
Source:
PAC, 1995, 67, 1307
(Glossary of class names of organic compounds and reactivity intermediates based on
structure (IUPAC Recommendations 1995))
on page 1313