One electron oxidation of 1,2-dihydroxy-9,10-anthraquinone and its transition metal complexes in aqueous solution: A steady-state and pulse radiolysis study

Studies on the oxidation of 1.,2-dihydroxy-9,10-anthraquinone (DHA) and its complexes with Cu-II, Ni-II and Fe-III by (OH)-O-. radicals and N-3(.) rad icals were carried out using steady-state gamma-radiolysis and pulse-radiol ysis studies. From the spectral properties of the product of oxidation it w as observed that (OH)-O-. radical reacts with DHA and its metal complexes t o form semioxidized quinone and OH-adduct while N-3. predominantly produce semioxidized quinone. Steady-state radiolysis studies suggested that the me tal co-ordinated OH-adduct of quinone gets oxidized to trihydroxy derivativ e of anthraquinone while the oxidized semiquinone undergo disproportionatio n. The rate constants for the oxidation of DHA by (OH)-O-. and N-3(.) were also determined by pulse radiolysis.