ENHANCED RAMAN-SCATTERING AT DIELECTRIC SURFACES .2. MOLECULAR ORIENTATIONS FROM POLARIZED SURFACE RAMAN-SCATTERING

The ability to obtain polarized Raman scattering for monolayer adsorbates deposited on oxide covered noble-metal island film structures has been closely examined. The relationship of the relative intensities of the in-plane enhanced electric field components to the depolarization ratios of the totally symmetric Raman vibrational modes of p-nitrobenzoic acid and phthalazine was found to indicate a constant depolarization of the in-plane electric field components induced by the island film particles themselves. With this information and with polarized Raman scattering information from nontotally symmetric phthalazine vibrations, we report a quantitative determination of the average surface molecular orientation of phthalazine monolayers at sputtered SiO2 surfaces. © 1990 American Chemical Society.