Hydroxyl radical, generation by Fenton

Figure 6.9 Abstraction of a phenolic hydroxyl proton by a hydroxyl radical generated by Fenton s reaction with hydrogen peroxide.

The interaction of 2,4-dimethylaniline with hydroxyl radicals generated by Fenton s reagent can be expected to produce aminophenols ... 

Figure 1 ESR spin-trapping technique using DMPO as the spin trapping agent (A) to detect hydroxyl radicals generated by Fenton reaction and to examine scavenging activity of (B) cinnamon extract and (C) whole grain soft wheat extract. ...

Oxidation rate constant k, for gas-phase second order rate constants, kOH for reaction with OH radical, kNG3 with N03 radical and kG3 with 03 or as indicated, data at other temperatures see reference k0H(calc) = 1.8 x to 12 cm3 molecule-1 s 1 at room temp. (SAR, Atkinson 1987) tropospheric lifetime x(calc) = 8-17 d, based on kOH(calc.) = (1.4 - 2.9) x io 12 cm3 molecule-1 s 1 for dichlorobiphcnyls at room temp. (Atkinson 1987) koH.(aq.) = 7.9 x 109 dm3 mol-1 s-1, PCB in Aroclor 1242 mixture, oxidized by hydroxyl radicals generated with Fenton s reagent in aqueous solutions at 25°C, half-lives range from 4-l 1 d in freshwater systems, 0.1-10 d in cloud water, > 1000 d in oceans for PCBs with as many as 8 chlorines (relative rate method, Sedlak Andren 1991) tropospheric lifetime x(calc) = 3.4-7.2 d, based on the experimentally determined gas-phase reaction kOH(exptl) = (2.0-4.2) x io-12 cm3 molecule-1 s-1, and the calculated kOH(calc) = (1.4 - 3.1) x io-12 cm3 molecule-1 s 1 at room temp. (Kwok et al. 1995)... 

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