The non-nucleophilic'' anion [Tf2N](-) competes with the nucleophilic Br- : an unexpected trapping in the dediazoniation reaction in ionic liquids

Imidazolium ionic liquids containing [Tf2N](-) anion are not as innocent as they are often considered; [Tf2N](-) is more reactive than Br- in heterolytic dediazoniation reactions.