SURFACE ENHANCED RAMAN-SCATTERING OF BENZO[C]CINNOLINE

SER spectra of benzo[c]cinnoline adsorbed on silver sols have been investigated and compared with previous results obtained for three diazines and 2,2′-bipyrimidine. Intense SER spectra were obtained for a very low concentration (5 × 10-5 M) of the adsorbate and the presence of a strong band in the 200-250 cm-1 region, attributed to AgN vibration, proves the relevant role of chemisorption. Unlike other diaza-aromatic molecules, SERS intensity for this molecule are not appreciably affected by the presence of NaCl. Creighton's surface selection rules, based on a vibrational assignment of benzo[c]cinnoline supported by zero order frequency calculations, suggest an "edge-on" orientation of the adsorbate on Ag particles. © 1990.