STOPPED-FLOW KINETIC STUDY OF REDUCTION OF A BINUCLEAR COMPLEX Fe3+.L.Co3+ BY ASCORBATE

Fe^3+.L.Co^3+ complex was prepared by reaction of salicylato pentaammine cobalt^3+ with ferric nitrate. Kinetics of reduction by ascorbate was followed spectrophotometrically. Fe^3+ was reduced, but Co^3+ was not. Reduction kinetics follows the rate law - d[Fe^3+ .L.Co^3+ ] ⁄ dt =k [Fe^3+ .L.Co^3+ ] where k obs= [k1 k3 [H^+ ]+k4 ⁄ k2+k3 [Asc][Asc] Temperature has no effect on the value of k2/k3. Redox Potential (Eo) of the complex at different pH were determined by cyclic voltametry. Using Eo values of complex and reductant, reduction rate constant were rationalized in terms of Marcus theory.