REACTIONS IN MICELLAR SOLUTIONS .13. KINETICS AND MECHANISM OF THE REVERSIBLE COMPLEXATION OF IRON(III) BY (ALPHA-BETA-S) (TETRAETHYLENEPENTAMINE) (SALICYLAT)COBALT(III) AND CIS-(AMMINE)BIS(ETHYLENEDIAMINE)(SALICYLATO) COBALT(III) IONS IN AQUEOUS ANIONIC MICELLAR MEDIUM

The kinetics of the reversible complexation of iron(III) with cis-(ammine)bis(ethylenediamine)(salicylato) cobalt(III) and (alpha-beta-S) (tetraethylenepentamine)(salicylato)cobalt(III) ions have been investigated at 25.0-degrees-C in the aqueous anionic micellar medium of sodium dodecyl sulphate.The kinetic findings indicate that the reactants are strongly bound to the micelle surface and the reaction occurs in the water rich zone of the micelle-bulk aqueous interface. The reaction of FeOH2+ with N5CoO2CC6H4OH2+ contributes to the formation of the binuclear species, N5CoO2CC6H4OFe4+, the dissociation of which is not catalysed by H+ in the micellar pseudo-phase unlike that for the aqueous medium reported earlier. The micellar retardation of the formation and dissociation of the binuclear species are governed by coluombic and hydrophobic interaction effects.