RT Journal Article
T1 Remembering the old propensity rules of the electromagnetic enhancement mechanism of SERS: reorientation of pyridine on silver electrode induced by the applied potential
A1 Valdivia Mantas, Samuel
A1 García-González, Francisco
A1 Aranda Ruiz, Daniel
A1 Ávila-Ferrer, Francisco José
A1 López-Tocón, Isabel
A1 Soto, Juan
A1 Otero, Juan Carlos
K1 Espectroscopía Raman
K1 Efecto Raman de superficie intensificada
K1 Química física
AB Electrochemical SERS of pyridine adsorbed on a silver electrode has been analyzed by comparing the spectra to the calculated normal Raman and resonance Raman intensities of model systems of pyridine bonded to linear silver clusters with different densities of charge through the nitrogen (Ag-NPy) or flipped through the hydrogen in the para-position (Ag-HPy). The changes observed in the ν(CH) region of the SERS have been investigated for the first time and related to a molecular reorientation at negative surface excess of charge of the metal in such a way that the ν(CH) bands with the highest (mode 2) and lowest (mode 13) wavenumber dominate this spectral region at positive or negative electrode potentials, respectively. The calculations support that the ν(CH) region is dominated by a specific vibration depending on pyridine orientation and suggest that both species coexist in the SERS recorded at negative potentials. This conclusion is supported by the SERS of centrosymmetric pyrazine which do not show this behavior and remembers the predictions from the old propensity rules of the so-called electromagnetic mechanism of SERS.
PB ACS
YR 2024
FD 2024
LK https://hdl.handle.net/10630/32454
UL https://hdl.handle.net/10630/32454
LA eng
NO Valdivia, S.; García-González, F.; Aranda, D.; Ávila Ferrer, F. J.; López-Tocón, I.; Soto, J.; Otero, J. C. Remembering the Old Propensity Rules of the Electromagnetic Enhancement Mechanism of SERS: Reorientation of Pyridine on a Silver Electrode Induced by the Applied Potential. J. Phys. Chem. C 2024, 128 (30), 12566–12574. https://doi.org/10.1021/acs.jpcc.4c03084
NO Funding for open access charge: Universidad de Málaga / CBUA. The authors thank financial support by the Spanish Ministerio de Ciencia e Innovación/FEDER (PID2022-138559NB-I00 and PID2021-122613OB-I00) and Universidad de Málaga/FEDER (FQM-103-G-FEDER). D.A. acknowledges the Spanish Goverment and European Union─NextGenerationEU─Maria Zambrano fellowship. F.G.-G. thanks the University of Málaga for fundings (Predoctoral contract A2 II Plan Propio de Investigación, Transferencia y Divulgación Científica). We also thank the University of Malaga SuperComputing and Bioinnovation Center (SCBI) for computational resources and the Universidad de Málaga/CBUA for funding open access charges.
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 19 ene 2026