Characterization of Long-lived Chromium(iv) Intermediates in Glutathione mediated Chromium(vi) Metabolites

Glutathione mediated reduction of chromium(vi) yielded a long-lived chromium(iv) intermediate in acidic aqueous solution, the molar susceptibility and the magnetic moment of this hypervalent species are 3.4( ± 0.2) × 10⁻³ cm³ mol⁻¹ and 2.8( ± 0.1) μ_B at 25°C; the first-order rate constants for the formation of the Cr^iv intermediate and its decay to Cr^III products were calculated to be 3.1 × 10⁻² and 6.0 × 10⁻³ s⁻¹ using excess tripeptide (25.0 mmol dm⁻³).