Cu(II) catalyzed oxidation of L-phenylalanine by hexacyanoferrate(III) in cationic micellar medium

Abstract

The kinetics of Cu(II) accelerated oxidation of L-phenylalanine (Pheala) oxidation in cetyltrimethylammonium bromide (CTAB) by hexacyanoferrate(III) was investigated by registering the decline in absorbance at 420 nm. Employing the pseudo-first-order condition, the reaction's advancement has been examined as an indicator of[CTAB], [Cu(II)], [OH-], [Pheala], [Fe(CN)63-], temperature, and ionic strength. The results show that [CTAB] is the critical parameter with a discernible influence on reaction rate. Pheala interacts with [Fe(CN)6]3- in a 1:2 ratio, and this reaction exhibits first-order dependency with regard to [Fe(CN)63-]. In the investigated concentration ranges of Cu(II), [OH-], and [Pheala], the reaction demonstrates fractional-first-order kinetics. A positive salt effect is indicated by the linear rise in reaction rate with additional electrolytes. CTAB catalyzes the process substantially, and once at its peak, the rate remains basically constant as [CTAB] grows. Reduced repulsion between surfactant molecules' positive charge heads brought on by the negative-charged [Fe(CN)6]3-, OH-, and [Cu(OH)4]2- molecules may be responsible for the witnessed drop in CTAB CMC.

Experimental and Computational Kinetic Assessment of Ruthenium (III) Catalyzed Oxidation of Paracetamol by Hexacyanoferrate(III): A Mechanistic Pathway

“…However, complications can arise when using HCF (III) in an acidic medium, as the oxidant can become complexed by one of the reduced products, hexacyanoferrate (II). While reactions in an alkaline medium have been found to be less prone to this complication, they are generally not as fast due to the reduced oxidation potential of the [Fe(CN) 6 ] 3À /[Fe(CN) 6 ] 4À redox couple [4] To address this issue, a range of transition metal ions have been used as catalysts in alkaline medium, including Osmium(VIII), [5,6] Ruthenium (III), [7,8] (IV), [9] (VI), [10] and (VIII), [11] Rhodium(III), [12] Iridium(III), [13] Paladium(II), [14] Molybdenum (IV), [15] and Cu (II), [16] Ru (III) [17] in micellar medium. HCF (III) is a potent one-electron oxidant and has redox potential of 0.36 V. It can act as a proton or electron abstracting reagent in oxidation reactions.…”