Collect. Czech. Chem. Commun. 1994, 59, 401-411

Kinetics and Mechanism of Acid Catalyzed Decomposition of 1-Phenyl-3,3-dialkyltriazenes

Miroslav Ludwig, Pavla Valášková and Oldřich Pytela

Department of Organic Chemistry, University of Chemical Technology, 532 10 Pardubice, Czech Republic


Five model 1-phenyl-3,3-dialkyltriazenes (methyl, ethyl, 2-propyl, butyl, cyclohexyl) have been synthesized and their acid-catalyzed decomposition kinetics have been investigated spectrophotometrically in aqueous ethanol (40 vol.%) with pivalic acid as the catalyst. The results show that the rate-determining step is catalyzed by the proton. The decrease in the observed rate constant at higher concentrations of pivalic acid is explained by the formation of an unreactive complex of the nondissociated acid and respective triazene. The steric effect of alkyl groups on the catalytic rate constants is discussed.