Disproportionation of arene radical anions is driven overwhelmingly by solvation, not ion pairing

The equilibrium constants for disproportionation of anthracene and perylene radical anions into neutral and dianion both in the absence and presence of solvent and for ion pairing of the dianions to tetraethylammonium ion have been computed by density functional B3LYP/6-311+G* theory. The disproportionation equilibrium is shown to be highly influenced by differential solvation effects and only modestly by ion pairing.