Kinetics of oxidation of certain pyrimidines by Ce(IV)

Abstract

The kinetics of the oxidation of certain biologically important pyrimidine bases (Uracil, Thymine, and 6‐Methyluracil) by Ce(IV) in aqueous H2SO4 has been investigated. A first‐order dependence of rate each on [Ce(IV)], [pyrimidine], and an inverse first‐order dependence on [H2SO4] has been observed. Rate and activation parameters for the oxidation of these pyrimidines have been computed. A suitable rate law and a mechanism consistent with the kinetic observations and product analysis have been proposed. © 1996 John Wiley & Sons, Inc.

Kinetics and mechanism of ruthenium(III) catalyzed oxidation of tetrahydrofurfuryl alcohol by cerium(IV) in sulfuric acid media

“…Therefore [HSO 4 ) ] shows a rate retarding effect (n ap = ) 0.51). The plot of 1/k obs versus [HSO 4 ) ] was found to be good linear with positive intercept and slope. Thus the hydrogensulfate dependence can be represented as follows: where a, b and c are constants under the experimental conditions.…”

“…In order to obtain the condition of pseudo first order, [ 4 ], and 2 ml of THFA solution of appropriate concentration were transferred separately to the upper and lower branch tubes of a k type two-cell reactor. After it was thermally equilibrated at the desired temperature in an HS-6 thermobath for about 5 min, the solutions were mixed thoroughly and transferred immediately into to a 10 mm thick quartz cell, then placed in a constant temperature cell-holder.…”

“…Metal complexes such as silver(III) [1], copper(III) [2], nickelate(IV) [3], and Ce IV ions [4] are good oxidants in a medium under appropriate condition. However, our preliminary observations indicate that oxidation of some organic compounds by Ce IV in aqueous sulfuric acid is kinetically sluggish, and that the process can be efficiently catalyzed by various metal ions even at trace concentration.…”

Determination of Salicylic Acid in Human Serum and Urine Samples by High-Performance Liquid Chromatography with Post-column Ru(bipy)32+-Ce(SO4)2 Chemiluminescence Detection

“…Therefore, we chose a Ce(IV) solution as the oxidant in the new chimiluminescence system. The Ce(IV) species exist as sulfated complexes in a solution of H2SO4; it has already been reported in the literature 14,15 that thereinto the reactive species of the oxidants are Ce 4+ , Ce(SO4)2 and HCe(SO4) 3-. The effect of the H2SO4 concentration concerning the CL intensity was investigated in the range of 0.02 to 0.5 mol/L.…”

A Kinetic and Mechanistic Study of Palladium (II) Catalysed Oxidation of Arginine by Cerium (IV) in Acid Media

“…Metal complexes [9][10][11][12] such as Ag(III), Cu(II), Ni(IV) and Ce(IV) ions are good oxidants in acid or alkaline media under appropriate reaction condition. However, our preliminary observations indicate that oxidation of some organic compounds by Ce(IV) in aqueous sulphuric acid is kinetically sluggish, and the process can be efficiently catalyzed by various metal ion even at trace concentration.…”