Oxidations by iron III

The reaction between complexes of the type Fe(H20)5X and V(H20)6 has been investigated by a flow method by measurements at the absorption maximum of the former species . Rate coefficients are recorded in Table 3 when 

X = H2O, OH , CP, NCS , and Nj in all these cases the rates of reduction are rapid compared with the rates of substitution of X in Fe(H20)6. No evidence is evinced for formation of VX complexes. It is noteworthy that OH exerts little effect on the rate of this reaction although it has a pronounced influence on the rate of other reactions of Fe(IlI) . This result, together with the observation that the other anions have similar effects on the rate, would seem to indicate that the FeX reactions proceed via an outer sphere path. The 

Fe(III) oxidises V(iri) to V(1V). Superficially the reaction is unexceptional the stoichiometry is simple 

The first term in (5.2) corresponds to the simple path represented by (5.1), rate coefficient ki. The form of the second term can be understood on the basis of the sequence 

Plots of the left-hand side of this equation versus corresponding ratios of [Fe(II)]/ [V(in)] are linear. Such plots appear to pass through the origin so that k2 must be large. The gradients of the plots yield a value for k since k 2l i 

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In spirooxaziridines like (114), /3-scission proceeds with ring opening. Stoichiometric amounts of iron(II) salt in acidic solution lead to the dicarboxylic acid derivative (115). The radical undergoes some interesting reactions with added unsaturated compounds. For example, pyridine yields a mixture of 2- and 4-alkylation products in 80% yield. Catalytic amounts of iron(II) ion are sufficient here since the adduct of the radical with pyridine is oxidized by iron(III) ion to the final product (116), thus regenerating iron(II) ion (68TL5609). 

When oxidized by iron(III) ions 4-aminoantipyrine reacts with phenols to yield colored quinonoid derivatives (cf. 4-aminoantipyrine — potassium hexacyanoferrate(III) reagent in Volume 1 a). It is an oxidative coupling based on the Emerson reaction. 

COMPLEXES OF DIFFERENT METALS OXIDATION-REDUCTION 5. Oxidations by iron(III) and ruthenium(III)... 

A synthetic antioxidant, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (613) is oxidized by iron (III) chloride or alkaline potassium ferricyanide to the quinone (614) and lactone (615) (75MI22303). 

Several 5,6-dihydro-2,3-diphenylpyrido[2,3-6]pyrazines 11 have been converted into the corresponding aromatic compounds 12 through oxidation by iron(III) chloride.68... 

Similar kinetic results are obtained in the presence of other cosubstrates (38), but the experiments with benzoin are especially significant because benzoin is not oxidized by iron (III). Consequently, the failure of substantial amounts of iron (III) to appear along with benzil in the reaction mixtures implies that iron (III) cannot be formed before a ratedetermining step. 

M Mandl, M Vyskovsky. Kinetics of arsenic (III) oxidation by iron (III) catalysed by pyrite in the presence of Thiobacillus ferrooxidans. Biotechnol Lett 16 1199-1204, 1994. 

Hydrogen sulphide and dimethyl-p-phenylenediamine form a sulphurous intermediate compound (intermediate stage), which changes into leucomethylene blue. The leucomethylene blue is oxidized by iron (III) ions to methylene blue. The methylene blue is measured photometrically at 670 nm. 

Luz RCS, Damos FS, Tanaka AA, Kubota LT, Gushikem Y. Electrocatalysis of reduced L-glutathione oxidation by iron(III) tetra-(iV-methyl-4-pyridyl)-paphytin (FeT4MPyP) adsorbed on multi-walled carbon nanotubes. Talanta 2008 76 1097-104. 

Exanaination of Table 3 shows that pernaanganate will oxidize iron(II) and oxalate, iodine will oxidize thiosulfate to dithionite, but iodide will be oxidized by iron(III) to iodine. 

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