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Autori: T. Iliescu, D. Maniu, V. Chis, F.D. Irimie, Cs. Paizs and M. Tosa
Editorial: Chemical Physics, 310, p.189-199, 2005.
FT-Raman and NIR surface-enhanced Raman (SER) spectroscopies have been applied to the vibrational characterization of non-natural b-amino acids, 3-amino-3-(furan-2yl)-propionic acid and 3-amino-3-[(5-benzothiazole-2yl)-furan-2yl]-propionic acid.
Semiempirical and density-functional theory (DFT) calculations on both amino acids in their zwitterionic forms have been performed in order to find the optimized structure and to compute the vibrational spectra. The NIR SER spectra in silver hydrosol
and Ag-coated filter paper have been recorded, compared and analyzed. Good SER spectra were obtained at the pH values where dipolar ion structures are present proving the chemisorption of b-amino acid molecules on the silver surface via positively charged
NH3 group. The carboxylate anion of both b-amino acids are parallel oriented, whereas the plane of rings is oriented perpendicular to the silver surface.
2004 Elsevier B.V. All rights reserved.
Cuvinte cheie: FT-Raman; DFT calculations; SERS; b-Amino acids