Kinetics of reaction of uranium(IV) and hexachloroiridate(IV) in acid perchlorate solutions. Evidence for a binuclear intermediate

Transition metal-catalyzed oxidation of l-asparagine by platinum(IV) in acid medium: a kinetic and mechanistic study

“…The first involves a simultaneous twoelectron transfer in a single step, while the second involves two successive one-electron transfer steps. If the transition states of the reductant and/or oxidant are unstable, a simultaneous two-electron transfer mechanism occurs, as observed in the oxidation of uranium(IV) by [PtCl 6 ] 2- [41]. In the present study, addition of acrylonitrile to the reaction mixture failed to give polymerized products.…”

Mechanism of Oxidation of L-Cysteine by Hexachloroiridate(IV) — A Kinetic Study

“…But in the kinetic investigations carried out earlier [19][20][21][22][23][24][25][26], using hexachloroiridate(IV) as oxidant, only first-order dependence on [IrCl 2À 6 ] was reported. However, it is interesting to note that in the present reaction second-order dependence in [hexachloroiridate(IV)] and first-order in [cysteine] was noticed and the derived rate law (Equation (15)) explains the observed facts.…”

“…From the ratio of slope to intercept(for the plot of 1/k¢¢ versus [H] + ) the value of 'K' and thereby the pK a of cysteine zwitterion was computed and found to be 1.12, which is in reasonably good agreement with a value of 1.71 reported earlier. Also, in the oxidations of thiourea and N,N¢-dialkylthioureas [19], uranium (IV) [20], tin(II) [21], arsenic(III) [22] and thiosulphate [23] by hexachloroiridate(IV), increase in [H + ] is accompanied by an appreciable decelaration of the rate of oxidation which is attributed to the reductant species. However, in the oxidations of aliphatic amines [24], glycine, alanine, valine, leucine, isoleucine [25] and methionine [26] by hexachloroiridate(IV), the rate of oxidation increases with increase in [H + ] and it is also explained based on the formation of protonated species which is more reactive [compared to the unprotonated form.…”

Kinetics and Mechanism of Oxidation of Nicotine by Permanganate Ion in Acid Perchlorate Solutions

“…The mechanistic approach of some reactions involving acidic permanganate as an oxidant has been based on the formation of intermediate complexes (Hassan R, 1991(Hassan R, , p.2018) and other results have been interpreted by free-radical mechanisms (Hassan R, 1992, p.661). Again, the mechanism of electron-transfer is sometimes suggested to be of successive one electron-transfer mechanism of outer-sphere type (Moore F, 1975, p.413) or inner-sphere nature (Hicks K, 1971(Hicks K, , p.1107.…”

“…However, the great importance of nicotine chemistry which is recognized, the information about the kinetics and mechanistics of nicotine oxidation is scarce. The kinetics of oxidation of many organic (Hassan R, 1991(Hassan R, , pp. 2018, inorganic (Hassan R, 1988, pp.…”