Study by SERS spectroscopy of the adsorption of 1H-1,2,4-triazole-3-thione on silver sols

Surface enhanced Raman scattering (SERS) spectra of 1H-1,2,4-triazole-3-thione (TAS) adsorbed on silver sols were recorded. From the comparison between the SERS and normal Raman spectra of TAS in aqueous and in NaOH solutions, it can be deduced that the substance adsorbs in the ionized thiolic form (TASA) on the silver surface. From the description of the vibrational normal modes related to the most enhanced bands in the SERS spectra, it can be deduced that the interaction with the silver sol occurs via the lone pairs of the sulphur and of one of the nitrogen atoms and that the orientation of the tetrazole ring is inclined with respect to the metal surface. (C) 2003 Elsevier Science B.V. All rights reserved.