Reactivity of the bis[1-Hydroxy-2-(Salicylideneamino)Ethane]Manganese(II) complex toward hydrogen peroxide: Kinetics and intermediates of reaction

✍ Scribed by Cleonice Rocha; Otaciro Rangel Nascimento; Ana Maria da Costa Ferreira

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 204 KB
• Volume: 30
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/(sici)1097-4601(1998)30:12<889::aid-kin3>3.0.co;2-t

✦ Synopsis

Kinetic studies of the oxidation of the bis [1-hydroxy-2-(salicylideneamino)ethane]manganese(II) complex by hydrogen peroxide in acetonitrile solutions, at are described. A first-order dependence on the total manganese and the per-(30.0 Ϯ 0.2)ЊC, oxide concentrations was verified, leading to the rapid formation of a Mn(III) intermediate, monitored by stopped-flow measurements, at with a rate constant 394 nm, k ϭ (1.15 Ϯ f The participation of hydroxyl radicals in the process was detected 5 Ϫ1 3 Ϫ1 0.03) ϫ 10 mol dm s . by spin-trapping EPR spectra. The final product was monitored both by EPR spectra, and spectrophotometrically by the slow decay of the intermediary Mn(III) species, with a rate constant It was identified as the corresponding mononuclear Mn(IV) Ϫ1 k ϭ (2.60 Ϯ 0.09) s . d complex, and characterized by different spectroscopic techniques. Comparative results of the reactivity of the starting complex versus molecular oxygen, leading to the same final product, were also discussed.