SURFACE ENHANCED RAMAN-SPECTRA OF BENZENE TRICARBOXYLATE ANIONS ON SILVER SOLS

Surface enhanced Raman spectra of hemimellitate, trimesate and trimellitate anions adsorbed on aqueous silver sols have been investigated. For each one, the results obtained at different pH values have been interpreted in terms of the degree of dissociation. Some conclusions concerning how the ions bond to the metal surface were obtained. The hemimellitate ion was found to bond to the metal through at least two carboxylate groups in an upright orientation, whereas the trimellitate ion seems to orientate face-on with respect to the surface. No unambiguous conclusion has been established for trimesate ion.