NOVEL PATHWAYS IN THE REACTIONS OF SUPEROXOMETAL COMPLEXES

The reaction of a 1:1 mixture of (H2O)(5)Cr(O-16(2))(2+) and (H2O)(5)C r(O-18(2))(2+) at pH 1 did not yield measurable amounts of (OO)-O-16-O -18. This result rules out a Russell-type mechanism (2(H2O)(5)CrO22+ - -> 2(H2O)(5)CrO2+ + O-2) for the bimolecular decomposition reaction. E vidence is presented in support of unimolecular (S(H)1) and bimolecula r (S(H)2) homolyses as initial steps in the decomposition of (H2O)(5)C rO22+ in strongly acidic solutions (pH less than or equal to 1). In th e pH range 4-5, (H2O)(5)CrO22+ undergoes hydrolysis-induced disproport ionation to (H2O)(5)CrO2H2+, Cr(H2O)6(3+) and O-2. The first step prod uces HO2./O-2(.-) which in further reaction with (H2O)(5)CrO2+ yields the observed products.