Kinetics and mechanism of the reduction of N, N'-salicylideneiminationiron(III) complex ion by L-ascorbic acid in aqueous acid medium

Abstract

The kinetics and mechanism of the reduction of the iron(III) complex ion, [FeSalen(H₂O)₂]⁺, by L-ascorbic acid has been investigated in aqueous perchloric acid medium at 28.5 ± 0.3 ^oC. The kinetic data was obtained by monitoring the rate of decay of the complex at 515 nm. Under pseudo-first order conditions of concentration of L-ascorbic acid at about 20-fold excess of concentration of complex, the rate of reaction increased with the concentration of ascorbic acid. Least square fits of observed rate against concentration of ascorbic acid were linear showing first order dependence of rate on concentration of the complex. Also, a plot of logk_obs against concentration of ascorbic acid gave a slope of 1.05 implying first order dependence on concentration of ascorbic acid. Second order rate constants were within (31.58 ± 0.50) × 10^-2 dm³ mol^-1 s^-1. More information can be found in the full text.