A simple water soluble diselenide derivative 1 shows radical scavenger properties towards alkyl and hydroxyl radicals (k3 (0°C)=6.8×108 M−1 s−1) in Fenton-type chemistry. The reaction rate between produceded alkyl radicals 2 and the diselenide overwhelms self-termination and halogen transfer reactions.

In the FeIII-FeV manifold the formation of the iron-carbon bond was found to be very fast, but the evolution to give ketone was slow at −20 °C and −40 °C. However, the efficiency at the latter temperature was good. The iron-carbon bond can be captured rapidly by I− or by PhSeH. We have confirmed that either way to measure the iron-carbon bond gives essentially the same results. In contrast to the FeIII-FeV manifold the reactions at −20 °C in the FeII-FeIV manifold are very fast for both iron-carbon bond formation and evolution to final products. In this manifold the reactions at −20 °C are more efficient than those at −5 °C.