What Is Methanium?
Methanium is a cation with the chemical formula CH5+. It consists of five hydrogen atoms bonded to a single carbon atom, forming a structure with a +1 charge.
Methanium is known as the simplest onium ion, distinguished from carbonium ions which are typically trivalent carbocations. It is a type of onium ion produced by the protonation of hydrides.
As a superacid, methanium can be synthesized in the laboratory as a dilute gas or as a dilute species in a superacid solution.
Methanium was first synthesized in 1950 and reported in a scientific paper by Victor Talrose in 1952.
Uses of Methanium
Currently, the uses of methanium are primarily restricted to laboratory research and have not yet been extensively developed for practical applications.
When methane is exposed to a very strong acid, such as a mixture of hydrogen fluoride and antimony pentafluoride, it can be protonated to form the pentacoordinated CH5+ ion. This methanium ion (CH5+) can desorb hydrogen to form the carbocation CH3+, which then initiates a polymerization process by attacking other methane molecules. Therefore, methanium is being investigated as a potential polymerization initiator.