caa a22 4500 605488282 CHVBK 20210128100454.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s00214-015-1661-3 doi (NATIONALLICENCE)springer-10.1007/s00214-015-1661-3 Revisiting the mechanism and the influence of the excitation wavelength on the surface-enhanced Raman scattering of the pyridine-Ag20 system [Elektronische Daten] [Nicolás Ramos-Berdullas, Diego López-Carballeira, Marcos Mandado, Ignacio Pérez-Juste] This work presents the application of a recent decomposition scheme of the Raman tensor into molecule and surface contributions to the study of the static and resonance Raman spectra of pyridine adsorbed on a Ag20 cluster, a typical probe for the theoretical study of surface-enhanced Raman scattering (SERS) spectra. The results obtained show that both the chemical and electromagnetic enhancements observed are related to changes on the polarizability and polarizability derivatives of the pyridine molecule. No significant contributions from the surface and from vibrational intermolecular coupling are found. Since similar incident lights produce remarkably different SERS spectra, the effect of excitation wavelength on the spectra of the PY-Ag20 complexes is also scrutinized. From the computed Raman excitation profiles and from the analysis of the electron density changes upon electronic transitions, it is established that the differences found can be related to the amount of electron density transferred from the silver cluster to pyridine upon excitation and to the distance between both units. These findings suggest that a proper knowledge of the effect of the excitation wavelength is necessary for obtaining a reliable theoretical interpretation of surface-enhanced Raman spectra. Springer-Verlag Berlin Heidelberg, 2015 Surface-enhanced Raman spectroscopy nationallicence Density functional theory nationallicence Adsorption nationallicence Pyridine-silver complexes nationallicence Ramos-Berdullas Nicolás Departamento de Química Física, Facultad de Química, Universidade de Vigo, 36310, Vigo, Spain aut López-Carballeira Diego Departamento de Química Física, Facultad de Química, Universidade de Vigo, 36310, Vigo, Spain aut Mandado Marcos Departamento de Química Física, Facultad de Química, Universidade de Vigo, 36310, Vigo, Spain aut Pérez-Juste Ignacio Departamento de Química Física, Facultad de Química, Universidade de Vigo, 36310, Vigo, Spain aut Theoretical Chemistry Accounts Springer Berlin Heidelberg 134/5(2015-05-01), 1-13 1432-881X 134:5<1 2015 134 214 https://doi.org/10.1007/s00214-015-1661-3 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00214-015-1661-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ramos-Berdullas Nicolás Departamento de Química Física, Facultad de Química, Universidade de Vigo, 36310, Vigo, Spain aut NATIONALLICENCE 700 1- López-Carballeira Diego Departamento de Química Física, Facultad de Química, Universidade de Vigo, 36310, Vigo, Spain aut NATIONALLICENCE 700 1- Mandado Marcos Departamento de Química Física, Facultad de Química, Universidade de Vigo, 36310, Vigo, Spain aut NATIONALLICENCE 700 1- Pérez-Juste Ignacio Departamento de Química Física, Facultad de Química, Universidade de Vigo, 36310, Vigo, Spain aut NATIONALLICENCE 773 0- Theoretical Chemistry Accounts Springer Berlin Heidelberg 134/5(2015-05-01), 1-13 1432-881X 134:5<1 2015 134 214