III and Manganese VII

A kinetic study of the oxidation of A -alkylphenothiazines (ptz) by man-ganese(III) has been made in a continuing series of investigations of the cation 

Kinetic and spectroscopic studies have been made of the one equivalent metal ion oxidation of phenoxazine and phenothiazine, At2NH, by iron(III) in acetonitrile solutions. The data have been analyzed kinetically using the sequence 

The formation of intermediates has been invoked in the oxidation benzoyl hydrazines, (L), by iron(III)-phenanthroline complexes.The principal reaction is via a species of the type [Fe(III)(phen)2L] with rate retardation observed when S04 is present. 

There has been considerable recent interest in the reductions of [Fe(CN)6]. The electron exchange with A -propyl-l,4-dihydronicotinamide is catalyzed by alkali metal ions. The increase in reaction rate is attributed to the polarizability of M and the observed linear free energy relationship is discussed. An outer-sphere mechanism is postulated in the oxidation of phenothiazines. A free radical mechanism involving the alcohol anion is invoked in the reaction of 1-and 2-propanol in aqueous alkaline media, the kinetic order being unity for [Fe(CN)6], OH, and alcohol concentrations. Catalysis by metal ions has also been observed in the presence of copper(II) and ruthenium(III) complexes. In the oxidation of a-hydroxypropionic acid in alkaline media,a Cu(II)-ligand complex is formed which is oxidized slowly to a copper(III) species. Alkaline ferricyanide oxidizes butanol, the process being catalyzed by chlororuthenium complexes.The rate law is consistent with oxidation of the alcohol by the Ru(III) followed by reoxidation of the catalyst by [Fe(CN)6]. The rate law is of the form  

The observed nonlinear dependence of the rate on [BuOH] is ascribed to a ratedetermining alcohol-independent reoxidation of catalyst. 

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