Effect of a static electric field on the vibrational and electronic properties of a compressed CO adlayer on Pt(110) in non aqueous electrolyte as probed by IRAS and IR-visible SFG spectroscopy
Résumé
The CO–Pt(110) in nonaqueous electrolyte electrochemical interface was studied by infrared reflection–absorption spectroscopy (IRAS) and infrared (IR)-visible sum-frequency generation (SFG) nonlinear vibrational spectroscopy over a wide range of applied potentials (–1.71 V/NHE). The integrated intensities of the IRAS and SFG peaks associated with resonant excitation of the atop CO internal stretch vibration (AIR and ASFG) showed distinct variations with . The influence of vibrational and electronic properties on the observed variations is discussed. Potential dependent dynamical charge transfer is not sufficient to explain the observed value of AIR/. It is shown that screening factors due to dipolar interactions between molecules within the compressed adsorbed layer must be taken into account in order to explain the variations of the IRAS and SFG data and that the observed behavior differences of AIR and ASFG with the potential are not necessarily related to changes in the Raman cross section of the adsorbate. ©2003 American Institute of Physics.