Izvestiya of Saratov University.
ISSN 1817-3020 (Print)
ISSN 2542-193X (Online)


frequency

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.

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 Some unpublished results are presented.

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 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.

The Influence of Hydrogen Bond on the Structure and IR Spectrum of Triphenyl Phosphite

Background and Objectives: The IR spectra of triphenyl phosphite (TPP) have been measured at temperatures of 12 and 320 K in five phase states: crystalline (monoclinic and hexagonal phases), “glacial”, amorphous and liquid. It is necessary to clarify the effect of hydrogen bonding on the structure and IR spectrum of TPP. Materials and Methods: The IR spectra were measured on the IFS-88 spectrophotometer using the OPUS software. The spectral resolution was 2 cm^(-1).