What is "methanium"

n. (context chemistry English) the carbocation, CH₅⁺, derived by the hydrogenation of methane

In chemistry, methanium is a positive ion with formula , namely a molecule with one carbon atom bonded to five hydrogen atoms and bearing a +1 electric charge. It is a superacid and one of the onium ions, indeed the simplest carbonium ion.

Methanium can be produced in the laboratory as a rarefied gas or as a dilute species in superacids. It was prepared for the first time in 1950 and published in 1952 by Talrose and Lyubimova. It occurs as an intermediate species in chemical reactions.

The methanium ion is named after methane , by analogy with the derivation of ammonium ion from ammonia .