Redox kinetics and reactivity of heterobinuclear cyano-bridged ethylenediaminetetraacetatoruthenium(III)hexacyanoferrate(II,III) in aqueous solution

Kinetics of the reduction of [Ru III (edta)(NC)Fe III (CN) 5 ] 4− (edta=ethylenediaminetetraacetate) with l -ascorbic acid (H 2 A) and the oxidation of [Ru III (edta)(NC)Fe II (CN) 5 ] 5− with peroxydisulfate (S 2 O 8 2− ) were studied spectrophotometrically. The rate of reduction was found to be first-order both with respect to [Ru III –Fe III ] and [H 2 A]. Similarly, the oxidation reaction was in first order in both Ru III –Fe II and S 2 O 8 2− concentrations. Based on the kinetic observations an Fe centered outersphere electron transfer mechanism has been suggested for both the oxidation and reduction processes.