Adsorption of toluene‐3,4‐dithiol on silver islands investigated by surface‐enhanced Raman spectroscopy

The adsorbtion of toluene-3,4-dithiol (TDT) molecules on Ag islands was investigated with surface-enhanced Raman spectroscopy (SERS). The SERS spectrum was compared with the ordinary Raman spectrum of TDT, and differences in spectral features were discussed with the support of density functional theory calculations. The disappearance of all the S-H-related bands in the SERS spectrum indicates that TDT adsorbs on Ag via both thiol groups, as supported by the emergence of a weak band at 223 cm(-1) attributed to Ag-S stretching. Signatures of Ag-S-C complexes suggest that the adsorption is partially disordered. The observation of all the vibrational modes involving the methyl group indicates that the methyl group is exposed, offering new functionalization possibilities of the surface.