FT-IR, FT-Raman, surface enhanced Raman scattering and computational study of 2-(p-fluorobenzyl)-6-nitrobenzoxazole

FT-IR and FT-Raman spectra of 2-(p-fluorobenzyl)-6-nitrobenzoxazole were recorded and analyzed. A surface enhanced Raman scattering spectrum (SERS) was recorded in silver colloid. Using Gaussian03 set of quantum chemistry codes, the vibrational wavenumbers and corresponding vibrational assignments were examined theoretically. The presence of CH2 and NO2 bands in the SERS spectrum indicates the nearness of these groups to the metal surface, which affects the orientation and metal molecule interaction. From the SERS study, it is inferred that the para substituted phenyl ring is more tilted while the tri-substituted phenyl ring assumes a nearly perpendicular orientation with respect to the metal surface. The results indicate that the B3LYP method is able to provide satisfactory results for predicting vibrational wavenumbers and structural parameters. The calculated first hyperpolarizability is comparable with the reported values of similar derivatives. The geometrical parameters of the title compound are in agreement with that of similar derivatives. (C) 2012 Elsevier B.V. All rights reserved.