Spectral and mechanistic study of the ruthenium(III) catalysed oxidation of gabapentin (neurontin) by heptavalent manganese: a free radical intervention

The kinetics of ruthenium(III) catalysed oxidation of Gabapentin by permanganate in alkaline medium at a constant ionic strength has been studied spectrophotometrically. The reaction between permanganate and gabapentin in alkaline medium exhibits 2:1 stoichiometry (KMnO4: gabapentin). The reaction shows first order dependence on [permanganate] and [ruthenium(III)] and apparent less than unit order dependence each in gabapentin and alkali concentrations. Reaction rate decreases with increase in ionic strength and decrease in solvent polarity of the medium. Initial addition of reaction products did not affect the rate significantly. A mechanism involving the formation of a complex between catalyst and substrate has been proposed. The activation parameters were computed with respect to the slow step of the mechanism and discussed.