Oxidation of L-cystine by chromium(VI) - a kinetic study

The kinetics of the title reaction was studied spectrophotometrically in HClO4 medium at 380 nm. The data suggested that the order with respect to cystine is fractional, whereas chromium(VI) follows first order kinetics. The reaction was second order in [H+]. Cysteic acid was found to be the main product of oxidation. A suitable mechanism was proposed leading to the rate law. The activation parameters were computed using linear least squares method. KEY WORDS: Oxidation, Cystine, Chromium(VI) Bull. Chem. Soc. Ethiop. 2008, 22(2), 305-310.