Intensity enhancement and spectral change in Raman scattering of mercaptobenzothiazole adsorbed on silver electrode

Mercaptobenzothiazole is adsorbed on silver electrodes in the form of ionized-thiol. Sudden changes in Raman intensity were observed in changing the concentration at 1×10⁻⁸ and 1×10⁻⁶ mol/l. The former change may be ascribed to the change in orientation of adsorbed molecule and the latter to the formation of multilayered film. The largest enhancement in Raman intensity is obtained for the species adsorbed in normal orientation. The addition of halide ion resulted in the conversion of the thiol species to the thione one. The conversion may be related to the effect of halide ion impeding anticorrosion action of mercaptobenzothiazole.