[26,27]. As reported by several previous works [14,25], the first
step in the reaction of metal complexes with H2O2 in most case
is the formation of a transient complex of metals (or a transient
ferrous peroxide complex for iron catalyst as specified by Winterbourn
[28]) which may decompose to the hydroxyl radical or
a higher oxidation state of the metal or it may yield an organic
free radical in the presence of organic substrates. The forming
of hydroxyl radicals via Fenton reaction is based on the relative
rates of the decomposition reactions of metal-peroxide complex
and that of its reaction with organic substrates. By applying