Kinetics of 2,2′-Bipyridyl-Catalyzed Oxidation of Isopropyl Alcohol with Chromic Acid

2,2′-Bipyridyl and some substituted compounds catalyze effectively the oxidation of isopropyl alcohol by chromic acid. The reaction is first order in chromium(VI), alcohol and 2,2′-bipyridyl; it is first order in hydrogen ions at high acidity and slightly alters to second order at low acidity. The proposed mechanism shows that the rate-limiting step is mainly the decomposition of a termolecular complex to products. However, at low acidity, the formation step of this complex is a little less reversible and hence somewhat rate-limiting. Electron-donating substituents at the 4-position enhance the catalytic activity. Electron-withdrawing substituents at the 4- and 2-positions diminish the reaction rates by electronic and steric factors.