Kinetics and mechanism of silver(I) catalyzed oxidation of tris(1,10‐phenanthroline)iron(II) with peroxodiphosphate in acetate buffers

Abstract

A kinetic study of the silver(1)-catalyzed oxidation of tris(1,lO-phenanthroline)iron(II) with peroxodiphosphate was carried out by estimating tris-complex at 510 nm. The reaction is found to conform to the rate law (i).with K2 and K3 being the acid dissociation constants of H~P208-and H~Pz082-, respectively. The silver(1) catalysis in the reaction has been explained on the basis of complex formation between pdp and silver(1).

Oxidation of tris(1, 10-phenanthroline)iron(II) ion by iodate and periodate ions in neutral medium

“…In the proposed mechanism the reduction of periodate takes place in the one-electron process involving the creation of IO,'-, which subsequently reduces to 1 0 3 -(reaction (10) Equation (23) is consistent with eq. (3) with kobh = Addition of 103-ions to the reaction medium moves the equilibrium (10) to the left preventing the creation of peroxo product in reactions ( 1 I ) and (12). In this case the autocatalytic process disappears and the rate of the reaction is controlled by ferroin dissociation (reaction (7)), Electron transfer takes place likely with the inner-sphere mechanism, since Fe(phen);+ is not formed even as an intermediate product.…”

“…[(phen), Fe00Fe(phen)2]4+ I Z F e (~h e n )~ 02+ (19) Fe(phen)2 (OH)2' ion created in reaction (19) takes part in the formation of peroxo complex of iron(II1) by the reactions ( 1 0)- ( 12). The oxidation state of iron in Fe(phen);?…”