Inhibition of oxidative induced decomposition of (αα′-diphenyl)azoethane by transition metal ions. Interactions of metal ions with α-phenylethylperoxyl radical

Abstract

(αα′-Diphenyl)azoethane (APE) decomposes faster in the presence of oxygen than in its absence by a factor >10². This oxidative-induced decomposition is suppressed by radical scavengers and transition metal ions both in their lower and higher valence states. The inhibiting effects of metal ions have been ascribed to their fast interactions with and stabilization of peroxyl radicals. When the metal concentration is low, the induced decomposition is observed after a specific suppression time which is determined by the concentration ratio of APE to metal ions. The effects of ligand and additives such as pyridine and carboxylic acid on the rate and products of decomposition of APE are also discussed.