Electron transfer reaction with amide—one electron oxidant system in solution

The kinetics of reduction of Mn(III) by acetamide, formamide (F), N-methylformamide (NMF), and N,N-dimethylformamide (DMF) have been measured spectrophotometrically at 50°C in aqueous acid perchlorate media. Four moles of Mn(III) are consumed for formamides and two moles of Mn(III) are consumed per mole of acetamide, leading in each case to the formation of the respective amines. All rates were first order in each reactant and were independent of Mn²⁺] and NaClO₄]. The reciprocals of observed rate constants are inversely dependent on acidity. A free radical mechanism consistent with these results has been proposed for the reactions. Activation energies and entropies are calculated for each reaction.