Abstract
The surface enhanced Raman scattering (SERS) spectra of piperidine and pyridine have been examined as a function of chloride ion and electrode potential at a polycrystalline Ag electrode. The A′ modes (symmetric with respect to the symmetry plane) of piperidine have a more negative intensity vs. potential maximum (ca. −0.8V vs. SCE) than the A″ modes (antisymmetric with respect to the symmetry plane) which appear at ca. −0.4 V vs. SCE. These results are interpreted in terms of a geometric electrostatic effect of the chloride ion. Three vibrational modes of piperidine have doublets assignable to the symmetric and antisymmetric representations, and both electrode potential and bulk chloride ion strongly affect the intensity ratio of these modes. For free pyridine the electrode potential has a more pronounced effect on the peak intensities of the v1 and v12 bands than changes in the bulk chloride ion concentration. In acidic solution, the pyridinium ion spectrum is strongly dependent on the chloride ion concentration indicating an ion-pair species at the electrode surface.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
