Formation and reactions of radical cations of substituted benzenes in aqueous media. A pulse radiolysis study

Radical cations of anisole, methylated benzenes, ethylbenzene, isopropylbenzene, tert-butylbenzene and n,Ndiaethylaniline were studied in aqueous media by pulse radiolytic technique. Absorption spectra and reaction kinetics of the radical cations were recorded. The radical cations are formed from the corresponding OH adducts by elimination of 0H~ either by a simple dissociation or by an acid catalyzed reaction.

The rate constants of the formation of the radical cations and their reactions with water, 0H~ and Fe+2 or the reaction of a proton loss were measured. The rate constants for reaction with water and OH together with the rate constant for the dissociation of the OK adducts art correlated with the ionization potential of the parent compound.

These correlations offer a possibility of predicting the acid-base properties of radical cations of substituted benzenes, or estimation of their ionization potential.