Kinetics of reduction of transition metal ions by sodium tetrahydroborate. Reduction of molybdenum(VI) and tungsten(VI)

Summary The kinetics of reduction of molybdenum(VI) and tungsten(VI) ions by NaBH₄ in buffered aqueous solution have been investigated. The reaction rate depends upon the first powers of the concentrations of the reactants. The temperature was varied, and the activation parameters were evaluated. Chemical and spectral evidence for the formation of molybdenum(V) and tungsten(V), as the reaction products, is presented. Plausible mechanistic pathways for these reactions are suggested.