Surface-enhanced Raman spectra of 2,2'-bipyridine molecules adsorbed on rough silver surfaces were obtained. The spectra are interpreted in terms of two adsorbed species, one of which closely resembles the classical [Ag(bipy)(2)](+) complex. The spectral features of the second adsorbate indicate the existence of 2,2'-bipyridine in the cis conformation oriented orthogonally to the surface. A thiol self-assembled monolayer, preadsorbed on the active surface, was used as a nanometric spacer to avoid the direct interaction of the molecules with silver. The same spectral features of the cis conformer are present even in this last case. The results are in agreement with an adsorption-induced transition of the thermodynamically stable trans conformation of the 2,2'-bipyridine molecule. Copyright (C) 1999 John Whey & Sons, Ltd.
Adsorption-induced conformational transition in 2,2 '-bipyridine on silver surfaces: a surface-enhanced Raman scattering study
COMPAGNINI, Giuseppe Romano;MARLETTA, Giovanni
1999-01-01
Abstract
Surface-enhanced Raman spectra of 2,2'-bipyridine molecules adsorbed on rough silver surfaces were obtained. The spectra are interpreted in terms of two adsorbed species, one of which closely resembles the classical [Ag(bipy)(2)](+) complex. The spectral features of the second adsorbate indicate the existence of 2,2'-bipyridine in the cis conformation oriented orthogonally to the surface. A thiol self-assembled monolayer, preadsorbed on the active surface, was used as a nanometric spacer to avoid the direct interaction of the molecules with silver. The same spectral features of the cis conformer are present even in this last case. The results are in agreement with an adsorption-induced transition of the thermodynamically stable trans conformation of the 2,2'-bipyridine molecule. Copyright (C) 1999 John Whey & Sons, Ltd.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
