KINETICS AND MECHANISM OF OXIDATION OF N,α-DIPHENYLNITRONES BY IMIDAZOLIUM DICHROMATE CATALYSED BY OXALIC ACID IN AQUEOUS DMF MEDIUM

摘要

The kinetics of oxidation of N,α-diphenylnitrones by imidazolium dichromate (IDC) catalysed by oxalic acid was carried out in 50% DMF-water medium and the reaction was followed iodometrically. The reaction is first order with respect to [nitrone], [IDC] and [oxalic acid]. The rate of the reaction increases with increase in [H~+], the reaction is fractional order with respect to [H~+]. The salt has a very small effect and Mn(II) has no significant effect on the oxidation of nitrone by IDC. The thermodynamic parameters have been calculated from the kinetic data. A mechanism involving the protonated nitrone and IDC as the reactive species has been proposed.