A pH-dependent surface-enhanced Raman spectroscopy investigation of the adsorption of 3-acetylpyridine
| Autor: | J. Barthelmes, G. Pofahl, W. Plieth |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Aqueous solution
Chemistry General Chemical Engineering Substituent Analytical chemistry Surface-enhanced Raman spectroscopy Analytical Chemistry Metal chemistry.chemical_compound symbols.namesake Adsorption visual_art Electrochemistry visual_art.visual_art_medium symbols Molecule Crystallite Raman spectroscopy |
| Zdroj: | Journal of Electroanalytical Chemistry. 329:329-338 |
| ISSN: | 1572-6657 |
| DOI: | 10.1016/0022-0728(92)80225-s |
| Popis: | Surface-enhanced Raman spectra (SERS) of 0.1 mol l −1 3-acetylpyridine (3-ACP), 0.1 mol l −1 NaCl solutions on a polycrystalline silver electrode are reported in the wavenumber range 500–1800 cm −1 as a function of pH. In order to determine the type of adsorbate (neutral or cationic species) the SER spectra are compared with the pH-dependent solution spectra and the spectrum of neat 3-ACP. In the pH region between 6.6 and 2.4, neutral 3-ACP is adsorbed end-on via the ring nitrogen atom. Furthermore, application of the image field theory to particular substituent modes, namely the carbonyl and CCH 3 vibration, leads to the conclusion of cis-configurated 3-ACP on the metal surface. At pH 1.4, the SER spectrum exhibits quite different features which are discussed in terms of an altered molecular structure in the double-layer region. An ion pair interaction as well as a planar orientation towards the electrode—the latter being feasible owing to a decrease in surface concentration—seem to be the most likely assumptions. |
| Databáze: | OpenAIRE |
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