CASPIAN JOURNAL
MANAGEMENT AND HIGH TECHNOLOGIES
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Read | Elkin Mihail D., Nuralieva Diana M., Dzhalmuhambetova Elena A., Gaisina Alfiya R., Alykova Olga M. // Caspian journal : management and high technologies. — 2012. — №1. — pp. 110-118. |
Elkin Mihail D. - Doctor of Physics, Professor, Astrakhan State University, 414056, Russia, Astrakhan, Tatishcheva 20a, elkinmd@mail.ru.
Nuralieva Diana M. - postgraduate student, Astrakhan State University, 414056, Russia, Astrakhan, Tatishcheva 20 a, kof1@aspu.ru.
Dzhalmuhambetova Elena A. - Ph.D., Astrakhan State University, 414056, Russia, Astrakhan, Tatishcheva 20a, alenna@list.ru.
Gaisina Alfiya R. - Assistant, Astrakhan State University, 414056, Russia, Astrakhan, Tatishcheva 20a, gaisinaalfiya@mail.ru.
Alykova Olga M. - Ph.D., Astrakhan State University, 414056, Russia, Astrakhan, Tatishcheva 20a, kof@aspu.ru.
This work is devoted to the construction of structural-dynamic models of carboxylic acid dimers compounds. The geometric parameters of molecules are defined for researching compounds, such as a valence bond lengths and angles between them. A method is described for evaluation of the anharmonic shift of bands in vibrational spectra of polycyclic compounds based on the results of ab initio quantum calculations for the adiabatic potential – cubic and quartic force constants. The frequencies of the vibrational spectra and their integrated intensities are obtained. Modeling of molecular geometry and anharmonic vibrational spectra was carried out under the suggestion of planar configuration of the compounds. The calculation was performed by density functional quantum method DFT/B3LYP with different basis. A complete interpretation of the fundamental vibrational states of the compounds is carried out. Accounting for polarization and diffusion effects of the atomic basis does not impact on the interpretation of vibrational spectra. Analysis of the adiabatic potential parameters suggests and the anharmonic shift was carried out . A modeling results of the studied compounds were compared with the available experimental data on vibrational spectra of the investigated compounds. It can be concluded that predictive quantum calculations for the adiabatic potential of carboxylic acid dimers is reliable and give the possibility of their spectral identification.
Key words: vibrational spectra,molecular spectra,IR-spectra,anharmonicity of vibration,carboxylic acid,carboxylic acid dimers,adiabatic potential,intermolecular interaction,intramolecular interaction,force constants