Carborane Acid: Protonation of the Weakest Bases by the Strongest Acid

Abstract

Carborane acid is the strongest Brönsted acid presently known, possessing unusually high acidity greater than fluorosulfuric acid. Protonation by a carborane acid have proceeded effectively towards the weakest bases such as benzene, fullerene, alkanes, and even carbon dioxide, producing corresponding reactive cations as salts with the least coordinating carborane anion. This short-review highlights recent reports on structural elucidations of several important cations using a carborane acid.