Unenhanced raman spectroscopy of benzene adsorbed on single crystal silver surfaces: Evidence for surface selection rules

✍ Scribed by Vickie M. Hallmark; Alan Campion

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 414 KB
• Volume: 110
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(84)85463-9

✦ Synopsis

We have interpreted the unenhanced Raman spectra of perdeuterobenzene adsorbed in submonolayer quantities on the (111) and ( 110) surfaces of silver to determine the surface activity of vibrational transitions for Raman scattering. We conclude that the interaction of the incident and reflected electric fields makes modes which transform as 2' (where Z is the surface normal) the most intense spectral features_ Bands which belong to the same representation as do XZ or YZ have decreased intensity, but may appear if their polarizability tensor components are large. X2, p and XY vibrations are very weak scatterers and typically will not appear. Reduction of the molecular symmetry upon adsorption does occur, and the molecule is sensitive to the atomic geometry of its adsorption site. Quadrupole poiarizability contributions to the induced dipole moment cannot be eliminated, but are defmitely not as important as the altered symmetry, at least on these smooth. we&ordered sir@e crystal surfaces.