Abstract
The kinetics of oxidation of [Co^sup II^NS(H^sub 2^O)^sub 2^]^sup 3-^ by N-bromosuccinimide (NBS) in aqueous solution has been studied spectrophotometrically in the 20-40 °C range. The reaction is first order each in [NBS] and [Co^sup II^NS(H^sub 2^O)^sub 2^]^sup 3-^, and the rate of reaction increases with increasing pH between 6.64 and 7.73. The thermodynamic activation parameters have been calculated. The experimental rate law is consistent with a mechanism in which the deprotonated [Co^sup II^NS(H^sub 2^O)(OH)]^sup 4-^ is considered to be the most reactive species compared to its conjugate acid. It is assumed that electron transfer takes place via an inner-sphere mechanism.[PUBLICATION ABSTRACT]