Preparation and Structures of Crystalline Aromatic Cation-Radical Salts. Triethyloxonium Hexachloroantimonate as a Novel (One-Electron) Oxidant.

Triethyloxonium hexachloroantimonate [Et(3)O(+)SbCl(6)(-)] is a selective oxidant of aromatic donors (ArH), and it allows the facile preparation and isolation of crystalline paramagnetic salts [ArH(+)(*), SbCl(6)(-)] for the X-ray structure determination of various aromatic cation radicals. The mechanistic relationship between the Meerwein salt [Et(3)O(+)SbCl(6)(-)] and the pure Lewis acid oxidant SbCl(5) is based on a prior ethyl transfer from oxygen to chlorine within the ion pair.