A mechanistic study of the electrochemical behavior of pendimethalin herbicide

The electrochemical reduction of pendimethalin was studied by controlled potential electrolysis, employing the mercury pool electrode, in Na2SO4 0.1 mol L−1 pH = 8.0, with a constant potential of −1.0 V vs Ag/AgCl. The analysis of the products obtained was carried out by nuclear magnetic resonance (NMR), reaching a possible mechanism of reduction for this pesticide, proved by means of chemical quantum calculations. In such a mechanism, there was the reduction of the two nitro groups to hydroxylamine, involving 6 electrons, followed by the reduction of only one nitro group to amine, involving two more electrons. A structural rearrangement of the -NHCH(CH2CH3)2 cluster to a -CH2CH3 in the pesticide molecule was verified.