Inner-sphere Oxidation of Acetato- diaqua-(2-hydroxobenzy- lidene)- 5- phenylthiazol- 2- amino Cobalt (II) Complex by N-bromosuccinimide

Abstract

KINETICS oxidation of acetato- diaqua-(2-hydroxobenzylidene)-5-phenylthiazol-2-amino cobalt (II) complex by N-bromosuccinimide (NBS) in aqueous media was studied spectrophotometrically over the 25
 
40 o+C range, 0.2 -0.5 mol dm-3 ionic strength, and pH range (6.1-7.3) for a range of NBS and [complex]. The reaction rate was first order dependence on [NBS] and [complex] and increased with decreasing [H+] over the pH's values. The experimental rate law was consistent with a mechanism in which the deprotonated form of the complex was considered as more reactive than its conjugate acid. Polymerization of acrylonitrile was taken as an evidence for the presence of free radical in the reaction mixture. It was assumed that electron transfer took place via an inner-sphere mechanism through the formation of the initial cobalt (III) products which were slowly converted to the final cobalt (III) products.

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