Vibrational study of tolazoline hydrochloride by using FTIR-Raman and DFT calculations

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2011-09, Vol.79 (5), p.1710-1714
• Main Authors: Contreras, C.D., Ledesma, A.E., Zinczuk, J., Brandán, S.A.
• Format: Article
• Language: English
• Subjects: DFT calculations; Force field; Molecular structure; Tolazoline hydrochloride; Vibrational spectra
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2011.05.041

[Display omitted] ► A complete assignment of the observed spectral features is proposed. ► Three intense bands were detected in the IR spectrum of the protonated species. ► The SQM force field was obtained for the protonated form. ► The topological properties for the protonated form were studied. ► The charge-transfer for the protonated form of tolazoline hydrochloride was studied. Quantum mechanical (QM) calculations have been carried out in order to study the tolazoline hydrochloride theoretical structure and vibrational properties. This compound was characterized by infrared and Raman spectroscopies in the solid phase. For a complete assignment of the IR and Raman spectra, the density functional theory (DFT) calculations were combined with Pulay's Scaled Quantum Mechanics Force Field (SQMFF) methodology in order to fit the theoretical frequency values to the experimental ones. An agreement between theoretical and available experimental results was found. Three intense bands in the infrared spectrum characteristic of the protonated species of the compound were detected. Also, the possible charge-transfer and the topological properties for both benzyl and imidazoline rings were studied by means of Natural Bond Orbital (NBO) and Atoms in Molecules theory (AIM) investigation.