Formation of dications bearing a S(OH)2+ group from long-lived 9,9-dimethyl-10 R-phenanthrenium cations in FSO3H–SbF5/SO2ClF/SO2: a mechanistic study†
Abstract
1
H and 13C NMR studies have shown that the long-lived 9,9-dimethyl-10-R-phenanthrenium cations (R = PhCC, Me, OH) generated in FSO3H–SbF5/SO2ClF/SO2/CD2Cl2 transform into long-lived 7-dihydroxysulfonio-9,9-dimethyl-10-R-phenanthrenium dications. The effect of the 10-R substituents on the reaction rate suggests that a key step in the reaction mechanism is addition of SO2 to protonated phenanthrenium cations.