CASPIAN JOURNAL
MANAGEMENT AND HIGH TECHNOLOGIES
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Read | Erman Eugene A., Elkin Michael D., Smirnov Vladimir V., Dzhalmuhambetova Elena А., Gaisina Alfiya R., Alykova Olga M. // Caspian journal : management and high technologies. — 2012. — №2. — pp. 77-85. |
Erman Eugene A. - Ph.D. (Engineering), Astrakhan State University, 414056, Russia, Astrakhan, 20a, Tatishchev st., kof@aspu.ru.
Elkin Michael D. - Sc.D. (Physics and Mathematics), Professor, Astrakhan State University, 414056, Russia, Astrakhan, 20a, Tatishchev st., elkinmd@mail.ru.
Smirnov Vladimir V. - Ph.D. (Physics and Mathematics), Astrakhan State University, 414056, Russia, Astrakhan, 20a, Tatishchev st., kof@aspu.ru.
Dzhalmuhambetova Elena А. - Ph.D. (Physics and Mathematics), Astrakhan State University, 414056, Russia, Astrakhan, 20a, Tatishchev st., alenna@list.ru.
Gaisina Alfiya R. - assistant, Astrakhan State University, 414056, Russia, Astrakhan, 20a, Tatishchev st., gaisinaalfiya@mail.ru.
Alykova Olga M. - Ph.D. (Pedagogics), Astrakhan State University, 414056, Russia, Astrakhan, 20a, Tatishchev st., kof@aspu.ru.
Structural and dynamic models of salicylic acid are proposed on the basis of ab initio quantum calculations of the geometric and electronic structure. The parameters of the adiabatic potential are determined, a vibrational states interpretation of the test compound is proposed in this work. The structural-dynamic models of its isomers are constructed, signs of their spectral identification are found. The analysis of the molecules conformational structure of the substance is made. A choice of method and basis for calculation of a fundamental vibrations frequencies and intensities of the bands in the IR and Raman spectra is justified. The technique for evaluation of anharmonicity with cubic and quartic force constants is described. The paper presents the results of numerical experiments, geometric parameters of molecules, such as the valence bond lengths and angles between them. We obtain the frequency of the vibrational states and values of their integrated intensities. The interpretation of vibration of isomers and comparison with experimental data are shown. General patterns in the behavior of the spectral bands of different isomers are given. Proposed frequency can be used to identify the isomers of the vibrational spectra of molecules. The calculation was performed quantum density functional method DFT/B3LYP. It is shown that this method can be used to modeling the geometrical parameters molecular and electronic structure of various substituted benzoic acids. It allows us to construct the structural-dynamic models of this class of compounds by numerical calculations.
Key words: salicylic acid,benzoic acid,ortho-substituted benzoic acid,isomers,vibrational spectra,IR spectra,anharmonic shift,adiabatic potential,hydrogen bonds