The vanadium(V)/vanadium(III) redox couple was investigated in an acidic organic medium by reduction of sodium metavanadate by hydrogen bromide with 1,2-dichloroethane as solvent in the presence of tetraglyme as a complexing agent. In the absence of dioxygen a vanadium(III)-tetraethylene glycol (teg) pentagonal-bipyramidal complex, [V(teg)(Br)2]+Br-, is formed. In the presence of dioxygen a catalytical cycle is initiated whereby vanadium(V) oxidizes hydrogen bromide to molecular bromine. The reduced vanadium(III) species thereby formed is reoxidized by dioxygen to vanadium(V) as confirmed by ESR and UV-vis of the organic phase.
|Number of pages||4|
|Journal||Journal of the American Chemical Society|
|Publication status||Published - 1989|
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