Electron spin resonance study of the generation of stable arene radical cations in molten antimony trichloride

Pure molten antimony trichloride has been found to act as an oxidizing agent toward polycyclic arenes, producing stable solutions of radical cations. The oxidizing power of the Sb/sup 3 +//Sb/sup 0/ couple has been shown to be considerably increased or decreased by the addition, respectively, of a few mole percent of a chloride ion acceptor (AlCl/sub 3/) or donor (Me/sub 4/NCl). ESR spectra and coupling constants are reported for several arene radical cations in this medium, including those for the previously unreported acenaphthene radical cation.