RT Journal Article
T1 Voltage selection of physisorbed or chemisorbed 4-cyanobenzoate on a nanostructured silver electrode and the dual electronic structure of charged metal-molecule hybrids.
A1 Valdivia Mantas, Samuel
A1 Ávila-Ferrer, Francisco José
A1 Otero-Fernández-de-Molina, Juan Carlos
A1 López-Tocón, Isabel
K1 Quimisorción
K1 Adsorción
K1 Efecto Raman de superficie intensificada
AB Applied electric potentials tune SERS wavenumbers due to vibrational Stark effect, but some modes of 4CNB- show two differentiated regions, being redshifted at more negative potentials than the potential of zero charge of the electrode but remain unshifted at positive potentials. DFT calculations have been carried out for a model where 4CNB- is linked through the carboxylate [Agnq-OOC(4CNB-)]q-1 or the nitrile [Agnq-NC(4CNB-)]q-1 to stick-like silver clusters [Agn]q with different densities of charge (qeff =q/n). The comparison between calculated and experimental wavenumber shifts points out that 4CNB- is always adsorbed through the carboxylate. The dual behaviour of the wavenumbers is due to the existence of two types of electronic structure of the metal-molecule hybrid. Physisorbed (P-hybrid, repulsive) or chemisorbed (C-hybrid, attractive) surface complexes are selected by the sign of the surface excess of charge of the electrode. The electronic structure of weakly bonded P-hybrid is very sensitive to the voltage and their wavenumbers are continuously shifted, while the wavenumbers of the strong C-hybrid remain almost unshifted. This result proves the dual nature of the electronic structure of molecules bonded to charged metal electrodes or nanoparticles which can be responsible of the qualitative changes observed in electrochemical or molecular electronics experiments.
PB Elsevier
YR 2021
FD 2021-11-30
LK https://hdl.handle.net/10630/28339
UL https://hdl.handle.net/10630/28339
LA eng
NO Samuel Valdivia, Francisco José Avila, Juan Carlos Otero, Isabel López-Tocón, Voltage selection of physisorbed or chemisorbed 4-cyanobenzoate on a nanostructured silver electrode and the dual electronic structure of charged metal–molecule hybrids,Applied Surface Science, Volume 579, 2022, 152071, ISSN 0169-4332, https://doi.org/10.1016/j.apsusc.2021.152071
NO Junta de Andalucía/FEDER (UMA18-FEDERJA-049 and P18-RT-4592)
DS RIUMA. Repositorio Institucional de la Universidad de Málaga
RD 22 ene 2026