Autocatalytic reduction of the cis-bis(2,2′-bipyridyl)dichlororhodium(III) ion in alkaline aqueous ethanol under a hydrogen atmosphere

Abstract

The ion cis-[Rh(bipy)₂Cl₂]⁺(bipy = 2,2′-bipyridyl) is reduced in alkaline aqueous ethanol under hydrogen to the known [Rh(bipy)₂]⁺ ion. A detailed kinetic study of this reaction has been carried out and the rate equation governing the reaction is shown to be of the form d[Rh^I]/dt=k[Rh^III]²[Rh^I]. The observed rate constant varies with 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.