Superacid–Catalyst Polymerization forIEMsPreparation

Superacid is an acid system that is more acidic than 100% sulfuric acid. It is several orders of magnitude more acidic than ordinary strong acids such as sulfuric acid and hydrochloric acid. The term “superelectrophilic activation” was first introduced by Olah to explain electrophilic reactivity in superacids. That is, when the electrophilic reagent reacts with the superacid to form the dicationic intermediate product, its reactivity will be significantly improved. The key to successfully performing chemical reactions involving carbocations is the formation of stable carbocations in low-nucleophilicity media. The superelectrophile is a reaction intermediate produced by further protonation. The catalytic reaction of superacids is widely used in the condensation of various aromatic monomers and polymers. Transition-metal-catalyzed-cross-coupling reactions are another class of reactions that have been utilized in polymer chemistry to build a polymer backbone composed of aromatic C—C bonds.