Radical Cation of Dibenzothiophene Fully Annelated with Bicyclo[2.2.2]octene Units: X-ray Crystal Structure and Electronic Properties

New dibenzothiophene 2 fully annelated with bicyclo[2.2.2]octene units was synthesized and oxidized to stable radical cation salt 2•+SbCl6-, whose structure was determined by X-ray crystallography. Although the intrinsic electronic structure of 2•+ is predicted to be close to structure A, an interaction with the counteranion makes structure B contribute significantly. A part of the salt 2•+SbCl6- underwent rearrangement to arenium ion 6+, whose structure was also clarified by X-ray crystallography.