STABILITY AND SOLVATION OF CARBENIUM IONS DERIVING FROM PROTONATION-DEHYDRATION OF ARYLCARBINOLS

The protonation-dehydration equilibria of several diaryl, triaryl, and diarylalkylcarbinols leading to carbenium ions have been investigated by the excess acidity method. The results are firstly employed for an assessment of the acidity functions (H-R and H-R) determined from tho se data. It is shown that both acidity functions are faulty in several respects, e.g. because they were determined from indicators for which parallelism of plots was hardly attained. In contrast, the excess aci dity method is shown to yield protonation parameters (M and pK(R+)) w hich can be interpreted in terms of structural and solvation effects o n the stability of carbenium ions. The relationship of these parameter s with enthalpies of reaction with FSO3H is also discussed.