Carborane acids H are a class of superacids, some of which are estimated to be at least one million times stronger than 100% pure sulfuric acid in terms of their Hammett acidity function values and possess computed pKₐ values well below –20, establishing them as some of the strongest known Brønsted acids.
What is carborane acid used for?
Carborane acids may also be used as strong, selective Brønsted acids for fine chemical synthesis, where the low nucleophilicity of the counteranion may be advantageous. In mechanistic organic chemistry, they may be used in the study of reactive cationic intermediates.
Is carborane the strongest acid?
It is immediately evident from their high chemical shift values that, as a class, carborane acids are stronger than conventional oxyacids. They easily outrank fluorosulfuric acid, the strongest known pure Brønsted acid on the H0 acidity scale (−15.1), as well as triflic acid (H0 = −14.1).
