Inverse photoemission of pyridine on "sers active" silver films

The unresolved a2 and b1 affinity levels of pyridine adsorbed on coldly-condensed silver films is found at 2.6±0.2 eV above EF and at 6.6±0.4 eV above EF for condensed pyridine. Resonant Raman scattering by "photon driven charge transfer" could therefore only be possible for directly adsorbed pyridine. This would explain the "first layer Raman enhancement". Observed differences in the UPS spectra of pyridine on Ag(111) and on coldly-deposited Ag films are discussed. © 1985.