RAMAN-SPECTROSCOPIC INVESTIGATION OF 4-AMINOBENZONITRILE ADSORBED ON SILVER

Surface-enhanced Raman scattering of 4-aminobenzonitrile has been investigated in a silver sol and at a silver electrode. The molecule was found to adsorb on the silver surface via both the amino and nitrile groups, with the benzene ring lying flat with respect to the surface. The most important interaction between the nitrile group and the surface was found to occur via pi coordination. The observations made in this work are entirely consistent with the previously proposed model that most conjugated aromatic nitriles adsorb on silver via the C=N pi system, and that their nu(CN) frequencies can either decrease or increase depending on the relative importance of nitrile-to-metal pi donation and conjugation breakup due to side-on coordination.