KINETICS AND MECHANISM OF OXIDATION OF DIETHYLAMINE AND TRIETHYLAMINE BY [RUV=O(EDTA)]- IN AQUEOUS-MEDIUM

The kinetics of oxidation of diethylamine and triethylamine by [Ru(v) = O(EDTA)]- were studied spectrophotometrically as a function of [Ru(v) = O(EDTA)]- and [amine] at a fixed pH of 5.0 and ionic strength of 0.2 M NaClO4. The reaction rate was followed by observing the disappearance of the characteristic peak at 393 nm of the oxo complex Ru(v) = O(EDTA)- with time. Oxidative N-dealkylation of tertiary and secondary amines produces secondary and primary amines respectively as oxidation products, the N-alkyl group being oxidized to the corresponding aldehyde. The oxidation reactions were studied at three different temperatures and activation parameters (DELTA-H++ and DELTA-S++) calculated. A mechanism involving a hydride shift from the alpha-carbon of the substrate to the oxo oxygen is proposed for the oxidation of amines by Ru(v) = O(EDTA)-. The experimental results are discussed with reference to the oxidation of the corresponding amines with molecular oxygen catalyzed by the [Ru(III)(EDTA)(H2O)]- complex.