Kinetics of electron transfer between bis( 2,2' -bipyridine )manganese(III) complex and thioureas in aqueous perchlorate media

Abstract

Kinetics of the redox interactions of thiourea and its N-substituted derivatives with manganese(III) complex of 2,2'-bipyridine has been investigated in aqueous solution by a stopped-flow technique in the acid range [H⁺], 0.10-0.50 mol dm^-3 at <i>l</i>= 1.0 mol dm ^-3 (NaClO₄) and at 30°C. A rapid initial increase in absorbance is followed by a slower decay of the formed species for all the four thioureas. Both the reaction steps are analysed and an inner sphere mechanism has been proposed for these reactions. The reactivity order for these thiourea derivatives is: ptu >tu >mtu >atu, and this bears a consequence to their substituent effects.