IR, Raman, SERS and computational study of 2-(benzylsulfanyl)-3,5-dinitrobenzoic acid

Abstract FT-IR and FT-Raman spectra of 2-(benzylsulfanyl)-3,5-dinitrobenzoic acid were recorded and analyzed. SERS spectra were recorded in silver colloid, silver electrode and silver substrate. The vibrational wavenumbers were computed using HF and DFT quantum chemical calculation methods. The data obtained from wavenumber calculations are used to assign vibrational bands obtained in infrared and Raman spectra as well as in SERS of the studied molecule. Potential energy distribution was done using GAR2PED program. The geometrical parameters of the title compound are in agreement with the reported similar derivatives. The presence of phenyl ring modes in the SERS spectra suggests a tilted orientation with respect to the metal surface in all cases. In all the three SERS spectra the NO 2 moiety shows an enhancement, which indicates the interaction with the metal surface. The first hyperpolarizability is high and the title compound is an attractive object for future studies of nonlinear optics.