Table 1.

Interactions of iron and copper ions with hydrogen peroxide and superoxide

Ferrous iron [Fe2+] + hydroperoxide [H2O2]	→ Ferryl [intermediate: iron-oxygen radical complex]
	→ Hydroxyl radical [OH⋅ + OH−] + ferric iron [Fe3+]
Ferric iron [Fe3+] + superoxide [O2⋅−]	↔ Perferryl [intermediate: iron-oxygen radical complex]
	↔ Ferrous iron [Fe2+] + oxygen [O2]
Comparable reactions can be written in which H2O2 reacts with cuprous [Cu+] ion to yield OH⋅, O2⋅−reduces cupric (Cu2+) ion to Cu+. Intermediate copper ion-oxygen complexes are formed