Substitution reactions of metallic complexes of 2,2′,2″-triaminotriethylamine. XVI. Kinetics of the (oxalato)(2,2′,2″-triaminotriethylamine) cobalt(III) cation in dilute and concentrated acid

Abstract

The main emphasis in the study has been the investigation of the kinetics of the stepwise reactions of [Co(tren)C 2O 4] + ion [tren = 2,2’,2”-triaminotriethylamine, N(CH 2CH 2NH 2) 3] in both dilute and concentrated acids, as well as the characterization in solution of some new Co(III) tren complexes. The aquation reaction was conducted in 1.0 M HClO 4 solution under various conditions. Protonation of a carbonyl oxygen in the complex appeared to increase the lability of the Co—O moiety, leading to a unidentate oxalate ligand. The stepwise anation of [Co- (tren)C 2O 4]+ to [Co(tren)Cl 2]+ in concentrated HCl was also followed. Both systems react by a dissociative reaction mechanism.