Physical properties and inclusion interactions of new stilbazolium salts: experimental versus theoretical study

The experimental and theoretical spectroscopic and spectrometric elucidation in solid-state and gas-phase on the interacting ionic species of applied oriented synthetic derivatives on the base of the stilbazolium salts as molecular template was reported. The correlation between the molecular structure, and vibrational properties within THz-regime (10-0.3 THz) was performed. The collective vibrations, and gas-phase stabilized ionic species were comprehensive studied by the Raman spectroscopy and matrix-assisted laser desorption/ionization mass spectrometry, using the embedded organic dyes in host matrixes. The performed solid-state quantum chemical calculations contributed to further understanding of the nature of the guest–host interacting systems as well as to explain the observed optical phenomena within the THz-region.     

Synthesis,molecular structure,and absolute configuration of 1-α-pheitylethyl-3-(2-cyanoethyl)-4-piperidone

The Michael addition of acrylonitrile to the pyrrolidine enamine of 1-(S--phenyl-ethyl)-4-piperidone proceeds with the formation of. a 1:1 mixture of l-(S--phenyl ethyl)-3-(2-cyanoethyl)-4-piperidone diastereomers. A diastereomer isolated in pure form was shown by x-ray diffraction structural analysis to have S-configuration of the new chiral center at C₍₃₎ of the piperidone ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp, 1656–1662, December, 1985.     

Selective precipitation of rare earth orthophosphates with hydrogen peroxide from phosphoric acid solutions

It has been shown for the first time that the use of hydrogen peroxide allows precipitation of rare earth orthophosphates (La–Tb) from phosphoric acid solutions at temperatures below 100°C. Either anhydrous or hydrated orthophosphates with monazite or rhabdophane structure, respectively, can be obtained depending on rare earth element position in lanthanide series and precipitation conditions (orthophosphoric acid and hydrogen peroxide concentration). Hydrated orthophosphates with rhabdophane structure can be prepared by precipitation with hydrogen peroxide for all studied rare earth elements.     

On the penetration of a rotating impactor into an elastic-plastic medium

This research is devoted to the modeling of high-speed rectilinear penetration of a rigid axisymmetric body (impactor with a flat bluntness) into an elastic–plastic media with account for its rotation about the axis of symmetry. The body has an arbitrary shape of the meridian. The resistance to the motion is represented as the sum of the body drag and the contribution of friction. The dynamic system governing the body motion is derived and the qualitative and numerical analysis of the projectile movement and perforation of a slab are performed. The problem of shape optimization of impactor with a flat bluntness is studied using evolutionary algorithm.     

Temperature dynamics of triglycine sulfate domain structure according to atomic force microscopy and dielectric spectroscopy data

A hydrogen-containing ferroelectric triglycine sulfate (TGS) was comprehensively studied with an atomic force microscopy (AFM) and dielectric spectroscopy. The domain structure dynamics was in situ investigated with piezoresponse force microscopy (PFM) during heating and cooling the TGS crystal near phase transition. Relaxation dependencies of domain boundaries general perimeter and domain dimensions were obtained. TGS dielectric spectra measured at the frequency range from 10 to 10¹¹ Hz were analyzed on basis of significant contribution of conductivity into the dielectric response of ferroelectrics and a good agreement with the experimental data was received. It allows us to obtain more information about temperature dynamics of the domain structure.     

Quantum-Chemical Calculations of the Reaction of Haloalkynes with Grignard Compounds

Two pathways of the reactions of methylmagnesium bromide with 1-chloro- and 1-bromo-3-methoxymethyl-1-propynes were simulated by the MNDO quantum-chemical method. The calculations predict initial coordination of magnesium to the C atom of the triple bond, which determines predominant nucleophilic substitution of the halogen atom according to the addition-elimination pattern.     

Effect of H/D-isotope substitution on the solubility and solvation thermodynamics of krypton in methanol solutions of carbamide

The solubility of gaseous krypton in CO(NH₂)₂—CH₃OH (CD₃OH) and CO(ND₂)₂—CH₃OD solutions with carbamide concentrations of up to 1.5 solvomolality units (0.026 mole fractions) was measured at 278, 288, 298, 308, and 318 K and at a partial gas pressure of 101325 Pa. The thermodynamic functions of dissolution (solvation) of krypton and the standard Setchenov coefficients were calculated. The solvation of Kr molecules increases upon deuterium substitution and with an increase in the temperature and carbamide concentration. In these solutions, specific contacts between the carbamide and methanol molecules play the predominant role.