A Kinetic Study of the Reaction of Periodate with Iodide Ions

Abstract

~ ~~The rate of the reaction of periodate with iodide in acidic media was studied. The rateAt higher acid concentrations the expression also contains a term in [H+Iz. This is confirmed by comparison with the data reported by Abel and Siebenschein. The reaction exhibits salt effects of low specificity, even in the presence of alkaline earth cations. Lanthanum and thorium ions have a retarding effect. The mechanism of reaction is discussed.

Kinetics and mechanism of the oxidation of some organic sulfides by morpholinium chlorochromate

“…The formation of a cyclic transition state entails a more exacting specificity of orientation and should result in much larger negative entropy of activation than that observed. The value of the entropy of activation obtained in this reaction is close to the value observed in typical reactions involving oxygen transfer, for example, oxidation of iodide ion by periodate [36] and that of MeSPh by hydrogen peroxide [27], periodate [28], and PFC [39] It is of interest to compare here the mode of oxidation of organic sulfides by PFC [39], PCC [41], pyridinium bromochromate (PBC) [42], and MCC. The oxidation by PFC, PBC, and MCC presented a similar kinetic picture, that is, the reactions are of first order with respect to the reductants.…”

“…(17) and (18), similar to that suggested for oxidations of sulfides and iodide ions by periodate ion [36] and for the oxidation of sulfides by hydrogen peroxide [26] and PFC [6]. The nucleophilic attack of a sulfide-sulfur on an MCC-oxygen may be viewed as an S N 2 process.…”

Ruthenium(III) catalyzed oxidation of hexacyanoferrate(II) by periodate in aqueous alkaline medium

“…The observed modest energy of activation (43.4+2 kJ mol ~) and relatively small entropy of activation (-9.5+1.0 J K -1 mol -x) suggest an inner/sphere mechanism and a probable involvement of a complex transition state in the reaction. An inner-sphere mechanism has also been involved in the oxidation of iodide ions by periodate [11,12]. Further support for this type of mechanism could be drawn from the oxidation of organic substrats by this oxidant.…”

Mechanism for the Oxidation of Sulfides and Sulfoxides with Periodates: Reactivity of the Oxidizing Species

“…[27][28][29][30][31][32][33] A mechanism involving oxygen-atom transfer steps has also been proposed for the periodate oxidation of the iodide ion. [34][35][36] b) Mechanisms involving the nucleophilic addition of the sulfur atom of the sulfide to the central heteroatom of the oxidizing agents were proposed for the reactions of sulfides with pyridinium chlorochromate, [37] iodosylbenzene diacetate [38] and with complexes of permanganate [39,40] and chromate ions. [41][42][43] c) The oxidations of sulfides with peroxydisulfates, [44] and peroxydiphosphates [45] are thought to proceed via the formation of an acyloxysulfonium intermediate of sulfuric and phosphoric acids, respectively.…”