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Naumov N. G. Artemkina S. B. Virovets A. V. Fedorov V. E. 《Russian Journal of Coordination Chemistry》2004,30(11):792-799
The [{Mn(H2O)3}2{Re6Se8(CN)6}] · 3.3H2O complex was produced on slow evaporation of an aqueous solution containing the salt of a cluster complex K4Re6Se8(CN)6 · 3.5H2O and a 23-fold excess of Mn2+. The cluster complexes [Re6Se8(CN)6]4– are linked in a crystal into the charged coordination layers [{Mn(H2O)3}4{Re6Se8(CN)6}3]4–
2 through the Mn2+ cations. The Mn2+ cations are coordinated in a layer by three cyano nitrogen atoms of the cluster complexes; the Mn–N bond lengths are 2.13(4) and 2.21(2) Å. Each [Re6Se8(CN)6]4– anion is bonded to three manganese cations Mn(1). The anions are bonded additionally to the Mn(2) cations disordered over two close positions. 相似文献
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V. V. Shcherbakov Yu. M. Artemkina E. N. Korotkova 《Russian Journal of Inorganic Chemistry》2014,59(9):922-926
An analysis has been performed of the dielectric characteristics and high-frequency (hf) electrical conductivity (EC) of aqueous solutions of NaCl. A method of the estimation of the static dielectric constant and of the time of dipole relaxation of concentrated aqueous solutions of NaCl in a wide range of concentrations and temperatures has been suggested. It has been shown that the limiting hf EC of the solutions and the hf EC at the frequency of 2455 MHz decrease with increasing salt concentration and differently change with increasing temperature: the limiting hf EC increases, whereas the hf EC at the frequency of 2455 MHz decreases. The decrease in the hf EC leads to a reduction of the rate of the hf heating of the NaCl solution with increasing salt concentration. 相似文献
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S. B. Artemkina N. G. Naumov A. V. Virovets V. E. Fedorov 《Russian Journal of Coordination Chemistry》2013,39(1):1-5
A solid solution Mo6 ? x Nb x I11 (x = 1.1–1.5) containing cluster cores {Mo5NbI8} is obtained by the high-temperature reaction of molybdenum, niobium, and iodine (550°C, 70 h, quartz ampule). According to the X-ray diffraction data, heating at 800°C in a molybdenum container results in the decomposition of the solution to Mo6I12 and Nb6I11. According to the X-ray structure analysis data, the compounds are isostructural to the high-spin modification Nb6I11 (space group Pccn). The presence of Nb atoms in the structure changes the structural type from the layered (Mo6I12) to framework structure, noticeably increases the metalmetal distances (2.661–2.716 Å, 2.695 Å) Mo6 octahedron with the retention of the distance from the metal (M) to the μ3-“capped” I atoms, and strongly elongates the M6-I-M6 bridges almost to the value observed in Nb6I11. 相似文献
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A relation has been found to exist between the limiting equivalent electrical conductivity of inorganic salt solutions, viscosity, temperature, and dielectric properties of the solvent. As temperature rises, the limiting equivalent electrical conductivity of aqueous solution of an inorganic salt has been shown to increase in direct proportion to the ratio of the dielectric permittivity to the dipole dielectric relaxation time, i.e., the limiting high-frequency electrical conductivity of the polar solvent. Expressions have been derived to be used in ascertaining the limiting equivalent electrical conductivities of inorganic salt solutions proceeding from the dielectric properties of the solvent. 相似文献
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V. V. Shcherbakov Yu. M. Artemkina 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2013,87(6):1048-1051
The behavior of the limiting high-frequency (HF) conductivity of water, methanol, ethanol, and propanol in a wide temperature range is considered. As the temperature is increased to its critical value, the static permittivity and the dipole relaxation time of the polar solvents decrease monotonically; however, the limiting HF conductivity, which is determined by their ratio, passes through a maximum. The maximum is explained by differences in the behavior of the temperature dependences of the relative temperature coefficients (RTCs) of static permittivity and the dipole relaxation time. It is shown that the maximum on the temperature dependence of the limiting HF conductivity corresponds to the equality of the RTCs of static permittivity and the dipole relaxation time. It is noted that in the temperature range corresponding to the maximum limiting HF conductivities of water and alcohols, the temperature dependences of the ion product of water and the conductivity of the considered polar solvents and solutions of inorganic salts in them also pass through maxima. 相似文献
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Overtone spectrum of o, m and p-nitrobenzaldehydes and p-chlorobenzaldehyde has been studied in 2000–12000 cm−1 region. Vibrational frequencies and anharmonicity constants for aryl as well as alkyl CH stretch vibrations have been determined.
We have also determined the internuclear distances for the aryl CH bond in the different molecules. The small variation observed
in these distances is an indication of the substitution effect.
It is observed that in the case of p-disubstituted benzens, the shift in aryl CH bond is proportional to sum of the Hammet σ of the substituents. However in the
case of o-disubstituted benzenes it is only 80% of the para-substituted shift. 相似文献
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The specific electrical conductivity (EC) of concentrated aqueous solutions of tartaric and oxalic acids was measured in the
range 15–90°C. Specific electrical conductivity versus concentration and temperature relationships were analyzed for the acids
studied in this work and for formic, acetic, propanoic, butanoic, chloroacetic, dichloroacetic, and trichloroacetic acids,
as well as for aqueous ammonia. As the electrolyte concentration increases, the EC passes through a maximum whose position
is independent of temperature. The maximal EC value of an aqueous solution of an associated electrolyte for a given temperature
and the concentration corresponding to this maximal EC were used as generalizing parameters. Over the entire ranges of the
temperatures and concentrations studied, normalized EC values (normalized EC is the ratio of the current EC to its maximal
value for a given temperature) for all electrolytes considered fall on one curve provided that the argument is a normalized
concentration (which is the ratio of the current solution concentration to its value at which specific EC has a maximal value). 相似文献
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