Stability Scales for Carbocations

To avoid ambiguity by intermixing different stability scales, it would be preferable to completely abandon the term carbocation stability and to clearly designate the properties that are going to be compared. Nevertheless, the term is in current use in discussions of chemical reactivity, and because the scales employed in this contribution are roughly corre- 

Iated with each other, we will continue to talk about carbocation stabilities in a qualitative sense. 

As discussed elsewhere [19], there are two main categories of stability scales, which relate either the Lewis- [Eqs. (la, b)] or the Bronsted-acidities [Eq. (lc)] of carbocations. In this contribution we will only refer to the Lewis acidity scales, i.e., scales that compare kinetic or thermodynamic features of the forward or backward reactions (la, b). 

The correlations between these scales, i.e., the justification for the further use of the term stability, will be discussed in Section F. 

Thermochemical properties referring to the gas phase are not obscured by solvent effects and are, from a fundamentalist s point of view, the ideal basis for stability scales. 

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