resumo
SERS of trans-3-hydroxycinnamic acid adsorbed on silver colloids have been analyzed in order to detect resonant charge transfer processes similar to a resonance Raman mechanism, involving the photoinduced transfer of an electron from the metal to the adsorbate (SERS-CT). Theoretical SERS-CT intensities for the neutral, anionic and dianionic forms have been calculated and it was found that the active SERS species corresponds to cinnamate ion linked to the metal through its carboxylate group. Moreover, it has been shown that the SERS-CT mechanism is operating in the SERS, explaining the strong enhancement of the band at ca. 1600 cm (1), assigned to the 8a mode. (C) 2008 Elsevier B.V. All rights reserved.
palavras-chave
CHARGE-TRANSFER MECHANISM; RESONANCE RAMAN; SELECTION-RULES; SPECTROSCOPY; ELECTRODE; PYRIDINE; COMPLEX; STATES
categoria
Chemistry; Physics
autores
Sardo, M; Ruano, C; Castro, JL; Lopez-Tocon, I; Ribeiro-Claro, PJA; Otero, JC
nossos autores
Mariana Isabel Coutinho Sardo
Investigador Auxiliar
Paulo Jorge Almeida Ribeiro Claro
Professor Associado com AgregaçãoGrupos
1 - Nanomateriais inorgânicos funcionais e híbridos orgânico-inorgânico
6 - simulação computacional e modelação multi-escala
agradecimentos
This work was supported by Spanish MEC (projects NAN2004-09312C03-01 and CTQ2006-02330) and the Portuguese Foundation for Science and Technology (FCT)-Laboratorio Associado CICECO. M. S. and C. R. also acknowledge FCT and MEC for their Ph. D. grants SFRH/BD/23400/2005 and BES-2007-17250, respectively.