Oxidation of Tyrosine by Hexacyanoferrate(III) in Aqueous Ethanoic Acid Medium–A Kinetic and Mechanistic Study

Abstract

The kinetics of oxidation of tyrosine by Fe(CN)63- have been studied in 40% AcOH-H2O containing 4.0 mol dm-3 HCl. The oxidation is made possible by varying the difference in redox potential by adding HCl and AcOH to the reaction mixture. The reaction is first order with respect to [Fe(CN)63- and fractional (0.72) order with respect to [tyrosine]. Increasing the acid concentration at constant chloride concentration accelerates the reaction. The order with respect to acid concentration is nearly two and H2Fe(CN)6- is regarded as the active oxidant. The initially formed product, Fe(CN)64- retards the reaction. A suitable mechanism is proposed and the reaction constants of the different steps involved have been evaluated. Activation parameters have also been calculated with respect to the slow step of the mechanism and discussed.

A promising methyl ester of pectic acid polysaccharide in biomedicine and pharmaceutics applications: Oxidation of methyl ester of pectic acid by alkaline hexacyanoferrate(III). A kinetic and mechanistic orientation

“…Although hexacyanoferrate(III) is known as a weak oxidant with redox potential of 0.36 and 0.4 V for [Fe(CN) 6 ] 3− /[Fe(CN) 6 ] 4− couple in acidic and alkaline solutions, respectively. 9,10 A considerable amount of work has been reported on the oxidation kinetics of organic 11,12 and inorganic [13][14][15][16][17][18] substrates by this oxidant. Therefore, redox reactions involving this oxidant are considered as a tool for chemical kinetics inception.…”

Mechanistic investigation of the oxidation of Cefuroxime by hexacyanoferrate(III) in alkaline conditions

“…Hexacyanoferrate (III) (HCF(III)) ion in alkaline medium known to oxidise inorganic and organic compounds [17][18][19][20][21][22][23][24][25][26][27][28][29] HCF(III)/ HCF(II) is a one electron oxidant with a redox potential of +0.36 V [30]. It is a moderate oxidizing agent and therefore, is used as electron or proton abstracting agent and results in the formation of a free radical intermediate during the oxidation of organic compounds [31].…”

Base‐catalyzed oxidation of sugarcane molasses by potassium ferricyanide in alkaline solutions

“…While hexacyanoferrate(III) is considered to be a mild oxidant with a redox potential of 0.36 and 0.4 V in acid and alkaline solutions for [Fe(CN) 6 ] 3– /[Fe(CN) 6 ] 4 – couples, respectively 9–10 . A number of studies have been conducted on the kinetics of organic oxidation 11 and inorganic 12–16 reducing agents by the ferricyanide ion. Oxidation‐reduction reactions with [Fe(CN) 6 ] 3 – are often called a chemical kinetic system because a variety of reaction mechanisms were very stable and had been observed in the event of redox reactions involving this oxidant.…”