SUPERACIDITY OF NEUTRAL BRONSTED ACIDS IN GAS-PHASE

The role of substituent effects on the recently established gas phase acidity scale of very strong neutral Bronsted acids was discussed. In several cases (highly dipolar and polarizable substituents attached to the acidity center, resonance stabilization of the anion relative to the neutral acid) the gas phase acidity of some C-H, N-H, O-H and S-H acids which make up the new acidity scale exceeds the acidity of such "traditionally" strong mineral acids as HCI, HBr, HI or H2SO4 by more than 30 powers of ten.