title: Vibrational spectral investigation, NBO, first hyperpolarizability and UV-Vis spectral analysis of 3,5-dichlorobenzonitrile and m-bromobenzonitrile by ab initio and density functional theory methods.
abstract: The FT-IR and FT-Raman spectra of 3,5-dichlorobenzonitrile and m-bromobenzonitrile have been recorded in the region 4000-400 cm(-1) and 3500-50 cm(-1), respectively. The optimized geometry, wave numbers and intensity of vibrational bonds of title molecules are obtained by ab initio and DFT level of theory with complete relaxation in the potential energy surface using 6-311++G(d, p) basis set. A complete vibrational assignments aided by the theoretical harmonic frequency, analysis have been proposed. The harmonic vibrational frequencies calculated have been compared with experimental FT-IR and FT-Raman spectra. The observed and calculated frequencies are found to be in good agreement. Stability of the molecule arising from hyperconjugative interactions, charge delocalization have been analyzed using natural bond orbital (NBO) analysis. The UV-Vis spectral analysis of the molecules has also been done which confirms the charge transfer of the molecules. Furthermore, the first hyperpolarizability and total dipole moment of the molecules have been calculated.
authors.affiliation: PG & Research Department of Physics, Periyar EVR College, Tiruchirappalli 620 023, India. Electronic address: josenthil74@gmail.com.
authors.forename: J
authors.initials: J
authors.lastname: Senthil kumar
authors.affiliation: Department of Physics, JJ College of Engineering and Technology, Tiruchirappalli 620 009, India.
authors.forename: S
authors.initials: S
authors.lastname: Jeyavijayan
authors.affiliation: Department of Physics, Government Arts College, Tiruchirappalli 620 022, India.
authors.forename: M
authors.initials: M
authors.lastname: Arivazhagan
mesh_terms: D008958:Models, Molecular; D008968:Molecular Conformation; D009570:Nitriles / Q000737:chemistry*; D011789:Quantum Theory; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013816:Thermodynamics; D014732:Vibration
chemical_list: C583554:2-bromobenzonitrile; C543727:3,5-dichlorobenzonitrile; D009570:Nitriles
keywords: 3,5-Dichlorobenzonitrile; FT-IR; FT-Raman; NBO; m-Bromobenzonitrile