A kinetic study of oxidation of 1,4‐dioxane by diperiodatonickelate(IV) in aqueous alkaline medium

Abstract

The kinetics of oxidation of 1,4-Dioxane (Dio) by Diperiodatonickelate (IV) (DPN) in aqueous alkaline medium at a constant ionic strength of 1.5 mol dm Ϫ3 was studied spectrophotometrically. The reaction shows first-order kinetics in [DPN] and less than unit order dependence each in [Dio] and [OH Ϫ ]. Addition of products, Ni(II) and periodate have no significant effect on the reaction rate. An increase in ionic strength and decrease in dielectric constant of the medium increases the rate. A mechanism based on experimental results, involving two paths, one [Dio] dependent and the other [Dio] independent is proposed. The constants involved in the mechanism are evaluated. There is a good agreement between the observed and calculated rate constants at varying conditions of experiments.

Genetic variants of p21 and p27 and hepatocellular cancer risk in a Chinese Han population: A case‐control study

“…The optimum pH for affording maximum grafting parameters is around 11.4 in this work, which is basically consistent with the previous investigation reported in our work 33. Furthermore, the optimum pH value 11.4 is approximately close to the one expected for the existence of ${\rm H}_{\rm 3} {\rm IO}_{\rm 6}^{{\rm 2} - } {\rm }$ and ${\rm H}_{\rm 2} {\rm IO}_{\rm 6}^{\rm 3-} {\rm }$ ions estimated from the several dissociation constants of periodic acid 32…”

“…An optimum value of pH was observed in the grafting copolymerization when investigating C %, P %, and E %. This is because, the two main active forms of Ni(IV) complex in alkaline medium, [Ni(H 3 IO 6 ) 2 ·(OH) 2 ] 2− and [Ni(H 2 IO 6 ) (H 3 IO 6 )(OH) 2 ] 3− , varies with the change of pH 30–32. More importantly, different types of Ni(IV) complexes possess different reactivity in the redox reaction.…”

Kinetics and Mechanistic Study of the Ruthenium(III) Catalysed Oxidative Decarboxylation of L‐Proline by Alkaline Heptavalent Manganese (Stopped flow technique)

“…Free radical scavenging experiment revealed such a possibility. This type of radical intervention in the oxidation of amino acids has also been observed earlier 27 .…”

“…The observed modest enthalpy of activation, relatively low value of the entropy of activation and higher rate constant for the slow step of the mechanism, indicate that oxidation presumably occurs by an inner-sphere mechanism. This conclusion is supported by earlier work 27 . Since scheme 3 is in accordance with generally well accepted principle of noncomplementary oxidations taking place in a sequence of one-electron steps, the reaction would involve a radical intermediate.…”

Oxidation of Isoniazid by Quinolinium Dichromate in an Aqueous Acid Medium and Kinetic Determination of Isoniazid in Pure and Pharmaceutical Formulations

“…This conclusion is supported by earlier observations. 22 Since the oxidation of isoniazid by QDC is a noncomplementary reaction, it may occur by the intervention of reactive chromium(IV) and chromium(V) species.…”