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Calculation of Structure and IR Spectrum of the 2,3-di-O-nytro-methyl-β-D-Glucopyranoside Molecule by Density Functional Method

Structural-dynamic models of the 2,3-di-O-nytro-methyl-β-Dglucopyranoside 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.

IR Spectra of Triphenyl Phosphite and Their Interpretation by Molecular Modeling

Background and Objectives: IR spectra of triphenyl phosphite (TPhPh) were measured in liquid (at 320 K), glassy and glacial phases and in hexagonal (metastable) and monoclinic (stable) crystal phases at 12 K. The observed differences in the spectra is a consequence of the implementation of the conformers of different types in the sample. To substantiate this hypothesis, structurally dynamic models of the three most probable conformers (I –III) were built. The conformers are different in angles of rotation of the phenyl rings around the C-O bonds.

Molecular Modeling and Vibrational Spectra of 4,4,’-clorobenzophenone

Vibrational infrared and Raman spectra of 4,4’-chlorobenzophenone have been measured at room temperature in the ranges 400–3200 and 0–3200 cm−1 respectively. Modeling of structure and vibrational spectra has been performed by a density functional theory method B3LYP/6-31+g(d) and 6-31-g(d). Energy, structure, components of the dipole moment and polarizability tensor, force constants, frequencies of normal modes in harmonic approximation and their intensities in the IR and Raman activity have been calculated. Interpretation of measured spectra is given.

IR Spectra of Cyclohexanol, Structural-Dynamic Models of Molecule

In wide temperature range IR spectra of cyclohexanol in different phase state (plastic phase, crystal phases II, III) have been measured in range 600–3600 см–1. Using density functional method B3LYP/6-31G structural – dynamic models of conformers of cyclohexanol molecule, which differs from each other by orientation of hydroxyl group relatively carbonic ring and cyclohexan, have been constructed. The energy, structure, dipole moments, polarizabilities and the frequencies of the normal modes in harmonic approximation and IR intensities have been calculated.

A History of One «Artefact»

A history of the phenomenon of fast oscillations of amplitude and momentary frequency of a signal (pulse) propagating in dispersive media is presented. This history is divided on three periods: first, from its discovery in 60-th of XX Century, second, its oblivion up to the end of XX C., and third – its open discussion from the end of XX C. to present days. A theory of the analytical signal is critically discussed. Some unpublished results are presented.

Influence of the H-bonding to the Structure and Vibrational Spectrum of 2,3-di-O-nytro-methyl-β-D-glucopyranoside

Structural-dynamic models of 2,3-di-O-nytro-methyl-β-D-glucopyranoside and its H-complexes were constructed by density functional method using the functional B3LYP in the 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 spectrum of the 2,3-di-O-nytromethyl-β-D-glucopyranoside and ethanol complexes is presented in range 600–3700 cm–1.

Hydrogen Bonding and its Influence on the Structure and Vibrational Spectra of Cyclohexanol

In the range of 600–3600 cm–1 in a wide range of temperatures, in different phase states (plastic phase I, the crystalline phase II and III) IR spectra of cyclohexanol have been measured. Using method of density functional theory (B3LYP) in the basis of 6-31G (d) the structural-dynamic models of conformers of cyclohexanol molecules differing from each other by orientation of hydroxyl group relatively carbonic ring and H-complexes with different structures, which presumably realized in polymorphic modification of cyclohexanol, have been constructed.

On the Аnalytical Signal and Yu. N. Zajko Article «A History of One "Artefact"»

The erroneous claims, made in the paper [1] (article of Yu. N. Zayko in «Izvestia of Saratov University. New Ser. Ser. Physics». 2012. Vol. 12, iss. 1. P. 3–11) have been discussed.

 

IR Spectra of Salol and theirs Interpretation by Molecular Modeling

IR spectra of salol have been measured at stable and metastable phases at temperature range from 11 to 298 K. IR spectra are different. We suggest that conformational mobility of salol and influence of H-bonding are responsible for the differences.