Trivalent Nickel. I. A Pulse Radiolytic Study of the Formation and Decomposition of the Ammoniacal Complex in Aqueous Solution

The oxidation of the NiII(NH3)n complex by NH2 radicals in aqueous solutions yields an unstable trivalent nickel complex. The specific rate of this reaction is 1 X 107 M~l sec-1. The absorption spectrum of the trivalent complex was measured. The mechanism of disappearance of the trivalent complex is via a second-order reaction with 2k < 3.5 X 107 M~l sec-1. The specific rate of the reaction OH + NH3åNH2 + H2O at pH 11.3 is 2.4 X 107 M-1 sec-1. The specific rate of oxidation of hydrazine by the trivalent nickel complex is 4 X 106 M-l sec-1.