The effect of hydrogen bonding on the structure and vibrational spectra of 2-benzylphenol has been studied. IR spectra were measured in the range 400 – 4000 cm-1 in the temperature range 11 – 335 K in stable and metastable phases solid-crystalline and liquid. Structural-dynamic models of the most stable in crystalline phase conformer of the 2-benzylphenol molecule and its H-complexes: a chain associate fragment and a cyclic tetramer, were constructed using the B3LYP/6-31g(d) density functional theory method. The parameters of adiabatic potentials are calculated: minimum energy, optimal geometry, force constants, dipole moment. Frequencies and forms of normal oscillations and their intensity in IR spectra are calculated. Based on the analysis of the results of modeling and measurements, conclusions were made about the structure of 2-benzylphenol samples and an interpretation of its IR spectra was given.

Radiation-induced formation of defects in binary crystals with significantly different atomic masses has been studied. The classical molecular dynamics method is used for a modified model that is an alternative for that with pair collisions. A computer program realizing the Verlet algorithm in the framework of the molecular dynamics approach is developed. The results obtained testify to the existence of a certain interval of incident particle energies, at which the so-called “heavy” clusters, i.e. clusters composed of heavier atoms, can be formed.

Влияние водородной связи на структуру и

Теоретическая и математическая физика Л. М. Бабков и др.ИК спектры трифенилфосфита и их интерпретация

L.M. BABKOV, J. BARAN, N.A. DAVYDOVA, I.V. IVLIEVA, E.A. PONEZHA, V.YA REZNICHENKO 3 1 Faculty of Physics, Saratov State University (83, Astrakhanskaya Str., Saratov 410026, Russia) 2 Institute of Low Temperature and Structure Research, PAS (2, Okolna Str., Wroclaw 50-950, Poland) 3 Institute of Physics, Nat. Acad. of Sci. of Ukraine (46, Prosp. Nauky, Kyiv 03028, Ukraine; e-mail: davydova@iop.kiev.ua) 4 Bogolyubov Institute for Theoretical Physics, Nat. Acad. of Sci. of Ukraine (14b, Metrologichna Str., Kyiv 03680, Ukraine)

МОЛЕКУЛЯРНОЕ МОДЕЛИРОВАНИЕ И КОЛЕБАТЕЛЬНЫЕ СПЕКТРЫ 4,4'-ХЛОРБЕНЗОФЕНОНА Л. М. Бабков 1

In situ IR spectroscopic investigation of the structural changes during the glaciation and crystallization processes in triphenyl phosphite (TPP) is performed in the 400-4000 cm(-1) spectral range. The 6-31G(d) basis set at the B3LYP level of the density functional theory has been applied to the calculation of the energies, dipole moments, geometric parameters, harmonic vibrational frequencies, and infrared intensities for different conformers of TPP. It is shown that at least five conformers differed by the bond lengths P-O and C-O and by angles in O-P-O, C-O-P, and P-O-C-C can be realized. The conclusion about probable conformational structures of different phases of TPP is drawn.

The structures of isolated 2,3-di-O-nitromethyl-β-D-glucopyranoside and its H-bonded complexes were modeled using density functional method B3LYP/6-31G(d). Their IR spectra were calculated in the harmonic approximation. It was concluded based on the modeling results that the H-bond affected the structure and IR spectrum of 2,3-di-Onitromethyl-β-D-glucopyranoside. The IR spectrum measured in the range 600–3700 cm–1 at room temperature was interpreted.

Structural-dynamic models of 2,3-di-O-nitro-methyl-β-D-glucopyranoside and its H-complexes have been obtained using density functional method. B3LYP hybrid functional and 6-31G (d) basis have been applied. Energies, structures, dipole moments, polarizabilities, frequencies of normal modes in harmonic approximation and IR intensities have been obtained. IR spectra of the complexes of 2,3-di-O-nitro-methyl-β-D-glucopyranoside and ethanol has been interpreted in 600-3700 cm–1 region. Taking into account the results of simulation we have interpreted IR spectrum of the sample in region 600-3700 cm-1, and determined the structure of the sample.

Structural-dynamic models of the 2,3-di-O-nytro-methyl-β-D-glucopyranoside molecule are constructed by density functional method in basis 6-31G(d). Energies, structures, dipole moments, polarizabilities, frequencies of normal modes in harmonic approximation and IR intensities have been calculated. Interpretation of IR absorption spectrum is presented in range 600–3700 cm–1. Advantages of model, which was constructed, compared with model, which bases on using valence-force field method and valency-optical theory, are discussed

The IR spectrum and structure of methyl-β-D-glucopyranoside have been studied theoretically taking into account the influence on them of the hydrogen bond formed in the sample. Density-functional theory with the B3LYP functional in basis 6-31G(d) was used to minimize the energies and calculate the structures, electro-optical parameters, force constants, frequencies of normal harmonic vibrations, and intensities in IR spectra of the simplest H-bonded dimeric complexes of methyl-β-D-glucopyranoside. The calculated spectra of H-bonded complexes were compared with those of the free molecule and the experimental spectrum in the range 400–3700 cm–1. Conclusions about the structure of methyl-β-D-glucopyranoside were made. The interpretation of its IR spectrum was refined.

A theoretical study has been made of the structure and IR spectrum of methyl-β-D-glucopyranoside with allowance for the influence of a hydrogen bond on them. Structural dynamic models of a free methyl-β-D-glucopyranoside molecule and its simplest complexes with the hydrogen bond, which represent variously structured dimmers, have been constructed by a density-functional method using a B3LYP functional in a 6-31G (d) basis. Energies have been minimized; structures, electrooptical parameters, force constants, and frequencies of normal modes in a harmonic approximation and their intensities in IR spectra have been calculated; hydrogen-bond energy has been evaluated. From the calculation results, the IR spectrum of a methyl-β-D-glucopyranoside sample has been interpreted and the conclusions on its structure and spectrum formation, and also on the capabilities of the employed method of density-functional theory have been drawn.

Using a density functional B3LYP/6-31G(d) method, the geometry, electro-optical parameters, quartic force field, and vibrational spectra (IR and Raman) of 2-biphenylmethanol have been calculated. A vibrational analysis was performed. The resulting IR and Raman spectra were interpreted in detail.

Structural-dynamic models of the methyl-β-D-glucopyranoside molecule are constructed by density functional method in bases 6-31 G(d), 6-31+G (d, p). Energies, structures, dipole moments, polarizabilities, frequencies of normal modes in harmonic approximation and IR intensities have been calculated. Interpretation of IR absorption spectrum is presented in range 400-3700 cm-1. Advantages of model, which was constructed, compared with model, which bases on using valence-force field method and valency-optical theory, are discussed