Abstract
A mechanistic approach to the influence of Mn(II) catalyzed
oxidative deamination of an anti-convulsant drug [GP] by
peroxomonosulphate (PMS) at a constant ionic strength of
1.0 mol dm
–3 have been studied,
spectrophotometrically. The reaction shows first order dependence on
[PMS] and [Mn(II)] and apparent less than unit order dependence
each in [GP] and alkali concentrations. Influence of dielectric
constant and ionic strength of the medium on the reaction rate have
been evaluated. It was observed that the added sulphate ion, the
reduction product of the oxidant, had insignificant effect on the
reaction rate. The reaction stoichiometry and oxidation products
deprotonated GP, SO4
2− and MnO2 have
been identified and a suitable mechanism has been proposed. The
reaction fails to initiate polymerization in the presence of
acrylonitrile under the experimental conditions employed. In
a composite equilibrium step, deprotanated GP binds to catalyst and
form a complex C that subsequently decomposes with oxidant to yield
the products. Investigations of the reaction at different temperatures
allowed the determination of the activation parameters and a tentative
reaction mechanism in good consistency with the kinetic results is discussed.