Oxygen Atom Transfer in the Oxidation of Aqueous Chromium(II) by Hydrogen Peroxide

Reduction of coordinated nitrosyls. Preparation, characterization, and reduction of nitrosylpentaaquochromium(2+)

“…3 Af"1 cm"1 ). 15 The spectrum of the 3 Af rinse was similar to that obtained on eluting the Cr dimer with 3 Af NaCl.…”

Reactivity of coordinated nitrosyls. 6. Preparation, characterization and reduction of nitrosylpentaaquoruthenium(3+) and reduction of various ruthenium ammine nitrosyls

“…Approximately 70% of the initial chromium (I I) is oxidized to Cr(H20)63+ which can be identified from the color, charge, and visible spectrum (Xmax 408 nm, e 13.3 M"1 cm"1; Xmax 574 nm, e 15.8 M"1 cm"1). 39 One equivalent of ruthenium (50% of the initial) per equivalent of chromium (12% of the initial) is separated as an orange 4+ or 5+ charged complex. On the basis of the sum of the absorbances of separated products at 280 nm (which is equal to that of the reaction mixture), the orange product comprises ~65% of the total absorbance at this wavelength.…”

Stoichiometry and mechanism of the chromium(II)-peroxydisulfate reaction

“…Entirely analogous initiation steps have been previously proposed for the chromium(II) reductions of organic peroxides.23•24 Furthermore, since one of the oxygen atoms of the hexaaquochromium(III) ion produced in the chromium(II)-hydrogen peroxide reaction originates in the peroxide oxygen, it was suggested that the initial inner-sphere one-electron step produces CrOH2+ and a hydroxyl radical. 25 It is noteworthy that eq 1 is also formally analogous to the chromium(II) reduction of organic halides,11-13 where halopentaaquochromium-(III) ions and organic radicals are produced in the initial one-electron inner-sphere step.…”