NATURAL SCIENCES

Journal of fundamental
and
applied researches

Structural and dynamic models of monogidroksyuratsilsin the condensed state

2013. 2, pp. 202-210

Erman Evgeny A.  - Ph.D. (Technical Sciences), Associate Professor, Astrakhan State University, 20a Tatischev St., Astrakhan, 414056, Russian Federation, kof@aspu.ru

Smirnov Vladimir V.  - D.Sc. (Pedagogy), Associate Professor, Astrakhan State University, 20a Tatischev St., Astrakhan, 414056, Russian Federation, vsmirnov@mail.ru

Dzhalmukhambetova Yelena A.  - Ph.D. (Physics and Mathematics), Associate Professor, Astrakhan State University, 20a Tatischev St., Astrakhan, 414056, Russian Federation, alenna@list.ru

Alykova Olga M.  - Ph.D. (Pedagogy), Associate Professor, Astrakhan State University, 20a Tatishchev St., Astrakhan, 414056, Russian Federation, kof@aspu.ru

Grechukhina Oksana N.  - Ph.D. (Physics and Mathematics), Associate Professor, Astrakhan State University, 20a Tatishchev St., Astrakhan, 414056, Russian Federation, kof@aspu.ru

Gaysina Alfiya R.  - Assistant, Astrakhan State University, 20a Tatishchev St., Astrakhan, 414056, Russian Federation, gaisinaalfiya@mail.ru

Ravcheeva Natalya A.  - Assistant, Astrakhan state University, 20a Tatishchev St., Astrakhan, 414056, Russian Federation, kof@aspu.ru

On the basis of ab initio quantum calculations for the adiabatic potential in this work we propose an interpretation of the vibrational states of possible conformers of the monomers and dimers of monohydroxy uracils. Constructed the structural-dynamic models of isomers, showed signs of their spectral identification. The analysis of the conformational structure of the compound have been studied. Validated the choice of method and basis of the frequencies of fundamental vibrations and the intensities of the bands in the IR and Raman spectra astimating. The paper presents the results of numerical experiments are defined geometrical parameters of molecules, such as the valence bond lengths and angles between them. We obtain the frequency of the vibrational states and the magnitude of their integrated intensities. Indicated general patterns in the behavior of the spectral bands of different isomers. Proposed frequency that can be used to identify the isomers of the vibrational spectra of molecules. Intensity of the bands of vibrational spectra for different tautomers can differ by an order that applies for the spectral identification of tautomers. Formation of dimers leads to a frequency shift of the bands, which are interpreted as stretching and deformation vibrations of NH bonds, involved in the formation of hydrogen bonds. The calculation was produced by density functional method DFT/B3LYP with basis 6-311G** and 6-311+G**. It is shown that this method can be used for build the structural-dynamic models of this class of compounds on the basis of numerical calculations.

Key words: monohydroxy uracil,conformer,tautomer,vibrational spectra,anharmonic,adiabatic potential

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