title: Density functional theory study on characterization of 3-chloro-1,2-benzisothiazole.
abstract: The FT-IR and FT-Raman spectra of 3-chloro-1,2-benzisothiazole (CBT) have been recorded and analyzed. Theoretical information on the optimized geometry, harmonic vibrational frequencies, infrared and Raman intensities were obtained by means of density functional theory (DFT) gradient calculations, using 6-311++G(d,p) basis set. Mulliken population analysis shows charge distribution on the molecule. Thermodynamic properties like entropy, heat capacity, zero point energy have been calculated for the molecule. The calculated HOMO and LUMO energies show the charge transfer occurs within the molecule. Stability of the molecule has been analyzed using Natural Bond Orbital (NBO) and Natural Localized Molecular Orbital (NLMO) analysis. The results of the calculations were applied to simulated spectra of the title compound, which show the excellent agreement with the observed spectra.
authors.affiliation: PG and Research Department of Physics, Periyar EVR College (Autonomous), Tiruchirappalli 620 023, India. rj_xavier@yahoo.com
authors.forename: R John
authors.initials: RJ
authors.lastname: Xavier
authors.forename: E
authors.initials: E
authors.lastname: Gobinath
mesh_terms: D054879:Halogenation; D008958:Models, Molecular; D008968:Molecular Conformation; D011789:Quantum Theory; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013844:Thiazoles / Q000737:chemistry*
chemical_list: D013844:Thiazoles; C466948:benzisothiazole