ELECTROCHEMICAL-BEHAVIOR OF MERCAPTO-N-BENZOXAZOLE AND ITS DIMER ON METAL-ELECTRODES

We showed that strong adsorption of mercapto-N-benzoxazole (MB) and it s dimer (DMB) involves adsorption of a radical-ion RS., which causes v ery strong bonding to the electrode. During polarization, the adsorpti on layer undergoes restructuring at negative potentials and this produ ces a novel redox reaction with E = 0.25 V. It may be suggested that t he heterocycle is subject to destruction at such potentials, and a com plex of mercury ions forms. This product increases the overvoltage for hydrogen evolution. MB causes the cathodic current of hydrogen evolut ion, whereas DMB is the source of MB generation (MB is the product of DMB reduction). Therefore, the catalytic current of hydrogen evolution is also observed in the presence of DMB.