No abstract available

No abstract available

[en] The possibility has been shown of improving the sensitivity and precision of determination of uranium (6) in the form of its tartrate complex by using spectropolarimetry instead of polarimetry and circular dichroism instead of optical rotatory dispersion. The method makes it possible to reduce reagent consumption, to expand a range of uranium(6) concentration, which could be determined, due to changes of the cell length and reading range. On the basis of the circular dichroism spectrum of the uranyl-tartrate complex, its symmetry has been estimated to be Dsub(4h) with the coordination number of four on the equatorial plane

[en] The possibility has been shown of significant improvement of the sensitivity and precision of determining molybdenum(6) as its tartrate complex by using spectropolarimetric measurements (instead of polarimetric ones at sodium D-line) at shorter wavelengths. Circular dichroism measurements in the region of a long-wave maximum allow the determination of 2 orders of magnitude lower molybdenum concentrations than by polarimetric analysis

[en] IR spectra of oxymethylene alkylcyclohexanones and their chelate compounds are investigated. Considered are the structure and properties of the chelates of copper, cobalt, zinc, europium, praseodymium, neodymium and the change of IR spectra during metallocycle formation. Force constants of M-O bonds are calculated for formyl cyclohexanone complexes

[en] The characteristics of solving the problem of radiative transfer through barriers with a complex geometric shape as applied to the problem of nondestructive radiation inspection are examined. A method of calculating photon radiation fields is described which is based on a successive transition from a homogeneous plane-parallel absorber to a medium with a complex geometry by gradually changing the shape of the absorber and subsequent evaluation of the effect of these changes on the radiation field by means of the theory of small perturbations

[en] Amides are synthesized from (+)-sec.-butylamine and (-)-α-phenylethylamine as well as from (+-),(+) and (-)-o-methylmandelic acids. Europium trisdipivaloylmethanate has been used for analysing the diastereomeric mixtures of the above amides by the PMR method. It is shown that the values of absolute and relative paramagnetic shifts of protons of diastereotypic groups OCH₃ depend on the composition of the diastereomeric mixture. This fact is related to the difference between the equilibrium constants of complexing paramagnetic shifting reagent - substrate for diastereomeric amides

No abstract available

[en] The ortho-palladization of R(+)-N-isopropyl-α-(2-naphthyl)ethylamine was realized under the conditions of the Cope-Friedrich reaction at an elevated temperature (64⁰C) compared with the normal temperature for the palladization of tertiary amines. It was established that the ortho-palladization of α-(2-naphthyl)ethylamines unsymmetrically substituted at the nitrogen atom is highly stereoselective and results in the fixation of the coordinated nitrogen atom of these ligands in only one of the two possible absolute configurations. On the basis of a comparative analysis of the chiral-optical and NMR characteristics of the obtained and of the previously investigated ortho-palladized compounds it was concluded that the nitrogen atom of the metallated ligand has the S/sup N/-configuration, determined by the R/sup C/-configuration of the adjacent asymmetric carbon center

[en] The Michael addition of acrylonitrile to the pyrrolidine enamine of 1-(S-α-phenyl-ethyl)-4-piperidone proceeds with the formation of a 1:1 mixture of 1-(S-α-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/sub (3)/ of the piperidone ring