A PULSE-RADIOLYSIS STUDY OF THE REACTIVITY OF (CH3)(2)COH RADICALS AND ELECTRON ADDUCTS OF O-PHENANTHROLINE AND 2,2'-BIPYRIDINE TO NEPTUNYLAND PLUTONYL IONS IN AQUEOUS-SOLUTIONS

The reduction of NpO22+ and PuO22+ ions by (CH3)(2)COH radicals and pr otonated electron adducts of 2,2'-bipyridine and o-phenanthroline in a rgon-saturated aqueous solutions of pH 1 was studied using the microse cond pulse-radiolysis technique. The rate constants of the reactions o f (CH3)(2)COH radicals with NpO22+ and PuO22+ [(1.5-1.8)x10(10)l mol(- 1)s(-1)] are apparently diffusion-controlled. For the reactions of ele ctron adducts, the rate constants are about one order of magnitude les s. The reaction rate constant of H-adducts of o-phenanthroline with Np O22+, is less than or equal to 3.5x10(6)l mol(-1)s(-1). The difference in reactivity of electron adducts and H-adducts is due to the differe nt structures of these radicals.