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 a t low acidity. The proposed mechanism shows that the rate-limiting ste p is mainly the decomposition of a termolecular complex to products. H owever, at low acidity, the formation step of this complex is a little less reversible and hence somewhat rate-limiting. Electron-donating s ubstituents at the 4-position enhance the catalytic activity. Electron -withdrawing substituents at the 4- and 2-positions diminish the react ion rates by electronic and steric factors.