The reaction pathway in which OH radical generated from ihe interaction of Fe~(2+) with H_2O_2 was investigated theoretically at the B3LYP/6-311G* * level. The role of ferrous ion in the radical generation was studied. The most favarable reaction pathway was confirmed. Interaction of Fe with H_2O_2 produces an intermediate complex (FeO_2H_2)~(2+) . Then 0-0 bond breaks to produce an intermediate complex (HOFeOH)~(2+) . Fe-OH bond breaks to produce OH radical. In the reaction, the strong charge interaction of Fe~(2+) with H_2O_2 ami the d orbital electron of Fe~(2+) promote the cleavage of 0-0 bond. The existence of ferrous favors the generation of OH radical.

Key words: HYDROGEN PEROXIDE, HYDROXY GROUP, FREE RADICAL, INTERACTIONS