Manganese(III) solutions were prepared by known electrochemical methods in sulfuric acid, acetic acid, and pyrophosphate media. The nature of the oxidizing species present in manganese(III) solutions was characterized by spectrophotometric and redox potential measurements. Kinetics of oxidation of L
Oxidation of Arginine by Manganese(III) in Pyrophosphate and Acetate media: A kinetic study
β Scribed by S. Chandraju; B. S. Sherigara; N. M. Made Gowda
- Publisher
- John Wiley and Sons
- Year
- 1994
- Tongue
- English
- Weight
- 719 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0538-8066
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β¦ Synopsis
Kinetics of manganese(II1) oxidation of L-arginine has been studied in the presence of pyrophosphate and acetate ions in acidic media at 328 K and 323 K, respectively. The nature of the oxidizing species formed in manganese(II1) solutions was determined by spectrophotometric and redox potential measurements. The reaction shows a first-order dependence on [manganese(III) pyrophosphate] in the pyrophosphate medium, pH 2-3, and a half-order on [manganese(III) acetate1 in HOAc-acetate medium. In both media, the kinetic order is one with respect to [argininel. The dependencies of the rate on the reduction product, manganese(II), concentration are zero-and inverse first-orders in acetate and pyrophosphate media, respectively. Effects of varying dielectric constant of the medium and of added anions such as acetate, pyrophosphate, fluoride, chloride, and perchlorate have been investigated, in both media. There is evidence for the existence of free radicals as transient species. Activation parameters have been evaluated using the Arrhenius and Eyring plots. Mechanisms consistent with the observed kinetic data have been proposed and discussed. Kinetic data for the oxidations of some a-amino acids by manganese(II1) species of different forms are summarized and compared.
π SIMILAR VOLUMES
Kinetics of oxidation of L-aspartic acid and L-glutamic acid by manganese(II1) ions have been studied in aqueous sulphuric acid, acetic acid, and pyrophosphate media. Manganese(II1) solutions were prepared by known electrolytidchemical methods in the three media. The nature of the oxidizing species
The kinetics of the oxidation of thiosulfate ion by [Mn(Y)I ~ (H4Y = trans-cyclohexane-l,2-diamine-N,N,N',N'-tetraacetic acid) and [Ni(L1)I2+ (HL1 = 15-amino-3-methyl-4,7,10,13-tetraazapentadec-3-en-2one oxime) have been investigated at 20.0, 30.0, and 40.0"C in aqueous solution and found to follow
## Abstract Manganese(III) (Mn(III)) has been stabilized in weakly acidic solution by means of pyrophosphate and the nature of the complex was elucidated spectrophotometrically. Stoichiometry of Mn(III)βoxidation of levodopa and methyl dopa in pyrophosphate medium was established in the pH range 2.
## Abstract The kinetics of a net twoβelectron transfer between an authentic Mn^IV^ complex, [Mn(bigH)~3~]^4+^ (__Fig.β 1__; bigHβ=βbiguanideβ=βC~2~N~5~H~7~), and nitrite in aqueous solution in the pH interval 2.00β3.60 is described. Stoichiometric data for the reaction clearly indicates Ξ[Mn^IV^]/Ξ