Abstract
The oxidation of D-glucose with Cr(VI) in aqueous perchloric acid proceeds via formation of a 1:1 complex which is considered to be chromium (VI) bonded to anomeric-OH group. The complex is formed within the time of mixing and remains stable for greater than or equal to 24 h in the absence of perchloric acid. The reaction products are D-1,4-glucolactone and Cr(III). Formation of CO2 has not been observed during the course of reaction under the experimental kinetic conditions. The reaction rate increases with [HClO4] and no acid-independent path has been observed. Manganese(II) inhibits the reaction rate and the order is found to be zero in [manganese(II)]. The kinetics of electron-transfer reactions to yield Cr(III) have been investigated spectrophotometrically and, on the basis of experimental data, mechanisms are presented and discussed.