title: Use of vibrational spectroscopy to study 2-[4-(N-dodecanoylamino)phenyl]-5-(4-nitrophenyl)-1,3,4-oxadiazole: a combined theoretical and experimental approach.
abstract: Quantum chemical calculations of geometric structure and vibrational wavenumbers of 2-[4-(N-dodecanoylamino)phenyl]-5-(4-nitrophenyl)-1,3,4-oxadiazole (AF51) were carried out by using density functional theory (DFT/B3LYP/6-311G(d,p) method. The fundamental vibrational modes were characterized depending on their potential energy distribution (PED). In order to predict the reactive sites for electrophilic and nucleophilic attacks of the title molecule, electrostatic potential surface has been plotted. The UV absorption spectrum was examined in chloroform solvent and compared with the calculated one in gas phase as well as in solvent environment using TD-DFT/ PCM approach. The (1)H NMR spectra was recorded. Comparison between the experimental and the theoretical results is satisfactory. The thermodynamic properties of the title compound at different temperatures have been calculated. A relationship between molecular structural features, non-linear responses and hyperpolarizability of AF51 has been established using vibrational spectra with emphasis on the role of intramolecular charge transfer mechanism in such organic NLO materials.
authors.affiliation: Department of Applied Physics, Institute of Engineering and Technology, MJP Rohilkhand University, Bareilly, India.
authors.forename: Saba
authors.initials: S
authors.lastname: Bee
authors.forename: Parag
authors.initials: P
authors.lastname: Agarwal
authors.forename: Archana
authors.initials: A
authors.lastname: Gupta
authors.forename: Poonam
authors.initials: P
authors.lastname: Tandon
mesh_terms: D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009596:Nitrophenols / Q000737:chemistry*; D010069:Oxadiazoles / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman
chemical_list: D009596:Nitrophenols; D010069:Oxadiazoles; C583463:1,3,4-oxadiazole; C024719:4-nitrophenyl
keywords: Density functional theory; FT-Raman; HOMO–LUMO energy gap; IR; Non-linear optics; UV analysis