Infrared dispersion analysis and Raman scattering spectra of taurine single crystals
| Autor: | Roberto L. Moreira, Anderson Dias, Ricardo P. S. M. Lobo |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Infrared Rays
Taurine Analytical chemistry 02 engineering and technology Dielectric Spectrum Analysis Raman 010402 general chemistry 01 natural sciences Molecular physics Analytical Chemistry Crystal symbols.namesake Electricity Dispersion (optics) Instrumentation Spectroscopy Scattering Chemistry 021001 nanoscience & nanotechnology Atomic and Molecular Physics and Optics 0104 chemical sciences Molecular vibration symbols Crystallization 0210 nano-technology Raman spectroscopy Raman scattering Monoclinic crystal system |
| Zdroj: | Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 188:276-284 |
| ISSN: | 1386-1425 |
| Popis: | A comprehensive set of optical vibrational modes of monoclinic taurine crystals was determined by Raman scattering, and infrared reflectivity and transmission spectroscopies. By using appropriate scattering/reflection geometries, the vibrational modes were resolved by polarization and the most relevant modes of the crystal could be assigned. In particular, we were able to review the symmetry of the gerade modes and to resolve ambiguities in the literature. Owing to the non-orthogonal character of Bu modes in monoclinic crystals (lying on the optic axial plane), we carried out a generalized Lorentz dispersion analysis consisting of simultaneous adjust of infrared-reflectivity spectra at various light polarization angles. The Au modes (parallel to the C2-axis) were treated within the classical Lorentz model. The behavior of off-diagonal and diagonal terms of the complex dielectric tensors and the presence of anomalous dispersion were discussed as consequences of the low symmetry of the crystal. |
| Databáze: | OpenAIRE |
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