FT-IR, FT-Raman spectra, and DFT computations of the vibrational spectra and molecular geometry of chlorzoxazone.

Far-IR, mid-IR, and FT-Raman spectra of the chlorzoxazone (CZX) were recorded. The observed vibrational wavenumbers were analyzed and assigned to different normal modes of vibration of the molecule. Density functional calculations were performed to support wavenumber assignments of the observed bands. The equilibrium geometry and harmonic wavenumbers of CZX were calculated by the DFT B3LYP method. All tautomeric forms and dimer form of CZX were determined and optimized. Additionally, experimental FT-IR spectrum in ethanol solution was recorded and compared with solid phase experimental data for the first time. The combination of the DFT B3LYP with polarized continuum model (PCM) was employed to characterize the solvent effects in ethanol solution.

HF and DFT studies of the structure and vibrational spectra of 8-hydroxyquinoline and its mercury(II) halide complexes.

The geometry, frequency and intensity of the vibrational bands of 8-hydroxyquinoline (8-HOQ) were obtained by HF and density functional theory (DFT) with BLYP and B3LYP functionals and 6-31G(d) as the basis set. The optimized bond lengths and bond angles are in good agreement with the X-ray data. The vibrational spectra of 8-HOQ which is calculated by the HF and DFT methods, reproduces the vibrational wavenumbers and intensities with an accuracy, which allows reliable vibrational assignments. Complexes of the type Hg(8-HOQ)X(2) [where X = Cl , Br] have been studied in the 4000-200 cm(-1) region, and assignment of all the observed bands were made. The analysis of the infrared spectra indicates that there are some structure-spectra correlations.