Pyridine N-oxide/trichloroacetic acid complex in acetonitrile: FTIR spectra, anharmonic calculations and computations of 1–3D potential surfaces of O–H vibrations
| Autor: | Valdas Sablinskas, Vytautas Balevicius, G. A. Pitsevich, V. Pogorelov, A. E. Malevich, E.N. Kozlovskaya, I. Doroshenko |
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| Rok vydání: | 2014 |
| Předmět: |
Models
Molecular Acetonitriles Proton Pyridines Chemistry Hydrogen bond Anharmonicity Analytical chemistry Infrared spectroscopy Molecular physics Potential energy Atomic and Molecular Physics and Optics Analytical Chemistry Vibration chemistry.chemical_compound Spectroscopy Fourier Transform Infrared Pyridine Trichloroacetic Acid Physics::Chemical Physics Acetonitrile Instrumentation Spectroscopy |
| Zdroj: | Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 120:585-594 |
| ISSN: | 1386-1425 |
| DOI: | 10.1016/j.saa.2013.12.008 |
| Popis: | FTIR spectra of pyridine N-oxide and trichloroacetic acid H-bonded complex in acetonitrile were studied at 20 and 50 °C. The calculations of equilibrium configurations of the complex and their IR spectra in harmonic- and anharmonic approximations were carried out at the level of B3LYP/cc-pVTZ/PCM. However both approximations turned out to be incompetent determining the frequency of the O–Н stretching vibration. In order to reveal the causes of essential discrepancies between calculated and experimental data one-, two- and three-dimensional potential energy surfaces (PES) of the O–H…O bridge proton motion in the frame of fixed other atoms in the complex were calculated. The frequencies of O–H…O stretching and bending vibrations were calculated by numerical solution of the Schrodinger equation. It is shown that only the approach of proton motion on the 3D PES allows obtaining a good agreement between the calculated and the experimental values of the frequencies of the О–Н stretching vibrations. |
| Databáze: | OpenAIRE |
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