The Solvent as Electrophile

Inevitably this specific electrophilic solvation must be included in the Y, Z and T scales of solvent ionizing power. Ideally some correction for the different extents of solvation of the anions Cl-, OTs-, I-) should be made, and then the various scales of solvent polarity may be more comparable. 

Quantitative indications of the relative magnitudes of solvation of the anions during solvolytic reactions can be obtained using eqn (5). By comparing the rate constants for solvolysis in acetic or formic acids with the rate constant for the ethanol/water mixture having the same Y value, a parameter [ Ew/kRC02H]y can be calculated. As 

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