FTIR, FT-Raman, SERS and DFT study on melamine

A joint experimental and theoretical study performed on neutral and protonated molecular forms of melamine is presented. FTIR. FT-Raman and surface-enhanced Raman scattering (SERS) in conjunction with density functional theory (DFT) calculations, were used for the characterization of the structural. vibrational and electronic properties of the neutral molecular form of melamine. The protonated molecular form was evidenced by SERS spectroscopy, and also, by the calculated Raman spectrum of the protonated endocyclic nitrogen of melamine molecule. The adsorption geometry of melamine on the silver surface was deduced based on the molecular electrostatic potential (MEP) map and SERS selection rules. (C) 2012 Elsevier B.V. All rights reserved.