SURFACE-ENHANCED RAMAN-SCATTERING SPECTRA AS A PROBE OF ADSORBATE SURFACE INTERACTION

Surface-enhanced Raman scattering evidence is given for the oligomerization and polymerization of pyrrole, thiophene and indole molecules on electrochemically roughened silver electrodes. It was shown that the types and amounts of species created on the electrode surface are very sensitive to the pretreatment procedure. The oxidation of monomers followed by oligomerization and polymerization occurs most easily for indole and pyrrole molecules. Thiophene is oxidized only on the non-totally reduced surface as obtained during oxidative-reductive cycling pretreatment under daylight conditions.