The Tris(pentafluorophenyl)methylium Cation: Isolation and Reactivity

Abstract

Herein, we present two different routes for the synthesis of the perfluorinated trityl cation, which allowed the handling of the free, uncoordinated species in organic solvents for the first time. The usage of the weakly coordinating anion [Al(OTeF₅ )₄ ]^- and its derivatives allows the characterization of this species by NMR spectroscopy and most importantly by single-crystal X-ray diffraction. The high hydride ion affinity of the cation is shown by hydrogen abstraction from isobutane. Furthermore, cyclic voltammetry reveals its oxidative potential which is supported by the reaction with tris(4-bromophenyl)amine, giving rise to the formation of the ammoniumyl radical cation, also known as "magic blue".