FUW TRENDS IN SCIENCE & TECHNOLOGY JOURNAL

(A Peer Review Journal)
e–ISSN: 2408–5162; p–ISSN: 2048–5170

FUW TRENDS IN SCIENCE & TECHNOLOGY JOURNAL

STUDIES OF THE KINETICS AND MECHANISM OF THE ELECTRON TRANSFER REACTIONS OF DIAQUOTETRAKIS(2,2’-BI
Pages: 11-23
Y. Mohammed, S.O. Idris, A.D. Onu, and J.F. Iyun


keywords: Catalysis/inhibition, electron, intermediate complex, kinetics, mechanism, transfer.

Abstract

The kinetics and mechanism of the electron transfer reaction of diaquotetrakis(2,2’-bipyridine)-µ-oxodiruthenium(III) ion (hereafter denoted as Ru2O4+ or [(H2O)2Ru2O]4+) and dithionite ions (S2O ) has been studied in aqueous medium at ionic strength, I, = 0.5 mol dm-3 and temperature, T = 31±1 ºC. The stoichiometry of the reaction was found to be 1:1. The rate of reaction showed first order kinetics with respect to [Ru2O4+] and [S2O ] respectively, second order overall. Rate equation for the reaction has been proposed as; . Varying I and dielectric constant, D, of the reaction medium had no effect on the reaction rates, while free radicals were not detected in the course of the reaction. Product analysis revealed [(H2O)2(bpy)2Ru]2+as the reduction product of [(bpy)2(H2O)RuORu(H2O)(bpy)2]4+. Spectroscopic evidence of formation of stable intermediate complex was lacking which, in addition to absence of intercept in the Michaelis – Mentenplot and catalysis/ inhibition of the reaction due to added ions, suggest the implication of outer sphere mechanism operating in the reaction. A plausible mechanism was proposed.

References

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