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Surface‐enhanced resonance Raman and hyper‐Raman spectroscopy of water‐soluble substituted stilbene and distyrylbenzene chromophores
Author(s) -
Leng Weinan,
Woo Han Young,
Vak Doojin,
Bazan Guillermo C.,
Myers Kelley Anne
Publication year - 2006
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.1467
Subject(s) - raman spectroscopy , chemistry , chromophore , photochemistry , resonance (particle physics) , resonance raman spectroscopy , acceptor , borohydride , aqueous solution , organic chemistry , catalysis , physics , particle physics , optics , condensed matter physics
Surface‐enhanced Raman spectra (SERS) are presented for two water‐soluble, donor–donor‐ or donor–acceptor‐substituted phenylene vinylene derivatives adsorbed on the surfaces of colloidal silver nanoparticles. The normally water‐insoluble, substituted stilbene and distyrylbenzene chromophores have been modified by attaching trimethylammoniumalkyl chains to the amino donor group, creating both aqueous solubility and a net positive charge that facilitates binding to citrate‐ or borohydride‐reduced silver colloids. A symmetrically donor‐substituted distyrylbenzene exhibits strong electronically pre‐resonant SERS spectra that are not highly dependent on excitation wavelength and are qualitatively similar to the solution‐phase resonance Raman (RR) spectra. A donor–acceptor‐substituted stilbene exhibits weaker SERS enhancement despite being fully electronically resonant. The spectra vary considerably with excitation wavelength and show new lines not present in the solution‐phase spectra, which are attributed to a photoproduct formed on the surface. Two‐photon resonant hyper‐Raman spectra are also presented for the donor–acceptor stilbene, both with and without surface enhancement. Copyright © 2006 John Wiley & Sons, Ltd.