Autocatalytic reduction of a bis(dimethylglyoxime) complex of rhodium(III) in alkaline aqueous ethanol

Abstract

The compound [Rh^III(DH)(DH₂)Cl₂](DH₂= dimethylglyoxime) is reduced in alkaline aqueous ethanol under an inert atmosphere to a rhodium(I) complex. A detailed kinetic study of this reaction has been carried out and the rate equation governing the reaction shown to be of the form d[Rh^I]/dt=k[Rh^III][Rh^I]. The observed rate constant varies with the inverse fourth power of the hydroxide-ion concentration, but is independent of the concentration of added chloride ion. The variation of rate with temperature is also reported. A mechanism is postulated to account for the experimental results.