Triazolium Cations: From the “Click” Pool to Multipurpose Applications

Accessing 1,2,3-triazole compounds through the copper-catalysed azide–alkyne “click” cycloaddition reaction is now a routine synthetic tool which has resulted in a huge amount of novel molecules of varied complexity bearing such heterocycles. 3-N-Alkyl-1,2,3-triazolium salts constitute an example of “post-click” chemistry arising from the “click” pool. This Focus review outlines emerging fields of application for triazolium cations, including their use as functional ionic liquids, as precursors of mesoionic carbenes, or as components of supramolecular assemblies and molecular machines.