Ruthenium(III) catalysis in the reaction of hexacyanoferrate(III) and iodide ions in perchloric acid medium

Abstract

RuCl 3 can further catalyze the reaction between hexacyanoferrate(III) and iodide ions, which is already catalyzed by the hydrogen ions obtained from perchloric acid. Rate, when the reaction is catalyzed only by the hydrogen ions, was separated graphically from the rate when ruthenium(III) and H + ions both catalyze the reaction. Reactions studied separately in the presence as well as in the absence of RuCl 3 under similar conditions were found to follow second order kinetics w.r.t. [I ) ]. While the rate showed direct proportionality w.r.t. [Fe(CN) 6 ] 3) and [RuCl 3 ]. At low concentrations the reaction shows direct proportionality with respect to [H + ] which tends to become proportional to the square of hydrogen ion concentrations. External addition of [Fe(CN) 6 ] 4) ions retards the reaction velocity while change in ionic strength of the medium has no effect on the rate. With the help of the intercept of the catalyst graph, extent of the reaction, which takes place without adding ruthenium(III) was calculated and it was in accordance with the values obtained from the separately studied reaction in which only H + ions catalyze the reaction. It is proposed that ruthenium forms a complex, which slowly disproportionates into the rate-determining step. Arrhenius parameters at four different temperatures were also calculated.

Kinetics and mechanistic aspects on electron‐transfer process for permanganate oxidation of poly(ethylene glycol) in aqueous acidic solutions in the presence and absence of Ru(III) catalyst

“…Although, Ru(III) has a wide application as a catalyst in the oxidation of many organic and inorganic compounds . A variety of oxidation mechanisms have been postulated depending on the effect of Ru(III) on the redox reactions.…”

“…A variety of oxidation mechanisms have been postulated depending on the effect of Ru(III) on the redox reactions. Therefore, the efficiency of Ru(III) catalyst is dependent on the nature of the substrate, oxidant, and the reaction conditions …”

“…Although, Ru(III) has a wide application as a catalyst in the oxidation of many organic and inorganic compounds. [8][9][10] A variety of oxidation mechanisms have been postulated depending on the effect of Ru(III) on the redox reactions. Therefore, the efficiency of Ru(III) catalyst is dependent on the nature of the substrate, oxidant, and the reaction conditions.…”

“…Therefore, the efficiency of Ru(III) catalyst is dependent on the nature of the substrate, oxidant, and the reaction conditions. [8][9][10] Preliminary experiments on the oxidation of PEG by the permanganate ion as a multiequivalent oxidant in HClO 4 -NaClO 4 media indicated the formation of 1:1 intermediate complexes prior to the rate-determining step, and the oxidation product was an acidic precursor on the contrary to that observed for oxidation of PEG by Ce(IV). 6 Again, the product was found to possess a high affinity for chelation with polyvalent metal ions.…”

Mechanistic Investigations of Uncatalyzed and Ruthenium(III) Catalyzed Oxidation of Vanillin by Periodate in Aqueous Alkaline Medium

“…In recent years, the use of transition metal ions such as osmium, ruthenium, palladium, chromium and iridium, either alone or as binary mixtures, as catalysts in various redox processes, has attracted considerable interest [7]. Ru(III) acts as a catalyst in the oxidation of many organic and inorganic substrates [8,9]. The catalyzed mechanism can be quite complicated due to the formation of different intermediate complexes, and different oxidation states of Ru.…”