Guilty and charged: a stable solution of the hexamethylbenzene radical cation as a ligand forming oxidising agent.

While it is often longed for very gentle oxidising agents with ideally close to no interaction with the generated substrate, it may sometimes be beneficial to have an oxidising agent at hand which is able to stabilise a reactive species directly after its generation. Here we present the synthesis of the hexamethylbenzene radical cation as a ligand forming oxidising agent. Its utility was demonstrated by the exemplarily chosen access to the mono-arene complex-cations of univalent gallium and indium [M(C6Me6)]+[Al(ORF)4]- (M = Ga and In).