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51.
The first cyclic unsaturated S-functional derivatives of 4,4-diphenyl-3,4-dihydro-2H-1,4-thiasiline, S-oxide, S,S-dioxide, and S-sulfonimide, were prepared. Oxidation of the hydrolytically less stable 4,4-dimethyl-3,4-dihydro-2H-1,4-thiasiline leads to the corresponding sulfoxide and sulfone along with the ring opening products, siloxanes containing the sulfoxide or sulfonyl group. 相似文献
52.
The thermal sila-Pummerer rearrangement of diastereomeric 2,3,3-trimethyl-1,3-thiasilinane S-oxides was studied. Introduction of the methyl group in the 2 position of 3,3-trimethyl-3-thiasilinane S-oxide slows down the rearrangement. When heated in CCl4, the trans isomer (2-Meeq, SOeq) converts into the cis isomer (2-Meeq, SOax) which rapidly rearranges into 2,2,7-trimethyl-1,6,2-oxathiasilepane. On the contrary, the isomeric 2,4,4-trimethyl-1,4-thiasilinane S-oxide is thermally stable up to 160°C in DMSO. The inversion at the sulfur atom in 2,3,3-trimethyl-1,3-thiasilinane S-oxides and 2,4,4-trimethyl-1,4-thiasilinane S-oxides under the action of triethyloxonium tetrafluoroborate was studied. The trans isomer of 2,3,3-trimethyl-1,3-thiasilinane S-oxide (2-Meeq, SOeq) forms with Et3O+BF 4 ? a salt which decomposes in two ways. The first involves recovery of the starting sulfoxide due to Sn2 substitution at the carbon atom of the ethoxy group, and the second, convertion into the cis isomer (2-Meeq, SOax) which rearranges into 2,2,7-trimethyl-1,6,2-oxathiasilepane. Under the same conditions, the cis isomer of 2,3,3-trimethyl-1,3-thiasilinane S-oxide (2-Meeq, SOeq) decomposes to form siloxanes. trans-2,4,4-Trimethyl-4-thiasilinane S-oxide (2-Meeq, SOeq) under the action of Et3O+BF 4 ? convers into the cis isomer (2-Meeq, SOax). The B3LYP/6-311G(d,p) theoretical analysis showed that the thermal inversion at the sulfur atom in the compounds studied has a high energy barrier. 相似文献
53.
A mathematical model is proposed for a frequency-modulated signal in the form of a system of Gaussian peaks randomly distributed in time. An analytic expression is obtained for continuous wavelet transform (CWT) of the model signal. For signals with time-varying sequence of peaks, the main ridge of the skeleton characterized by frequency ν max MFB (t) is analyzed. The value of ν max MFB (t) is determined for any instant t from the condition of the CWT maximum in the spectral range of the main frequency band (MFB). Double CWT of function ν max MFB (t) is calculated for a frequency-modulated signal with a transition regions of smooth frequency variation (trend) as well as with varying frequency oscillations relative to the trend. The duration of transition periods of the signal is determined using spectral integrals E ν(t). The instants of emergence and decay of low-frequency spectral components of the signal are determined. The double CWT method can be used for analyzing cardiac rhythms and neural activity, as well as nonstationary processes in quantum radio physics and astronomy. 相似文献
54.
O. P. Suslova I. V. Karpov A. V. Radievskii 《Russian Journal of Physical Chemistry B, Focus on Physics》2013,7(5):652-655
An analysis of the results of lidar observations in the lower atmosphere and observations of the total electron content in the ionosphere (TEC) in Kaliningrad (53°N, 22°E) during the period of solar terminator passage is presented. The observations at troposphere altitudes were performed with a two-wavelength atmospheric lidar (532 and 1064 nm). The ionospheric TEC was determined using signals from GLO-NASS navigation satellites. The observations in the lower atmosphere were performed in February and March 2012, starting ~1 h before sunrise and ending ~1–2 h after sunrise, whereas ionospheric observations were performed continuously throughout the day. Analysis of the spectrum of the observed parameters showed that, during solar terminator passage, the lower atmosphere and ionosphere parameters vary with periods of 4–6 min. Variations of the parameters in the atmosphere with these periods are associated with the propagation of acoustic-gravity waves (AGW). Analysis of the experimental results shows that AGW arise in the lower atmosphere and propagate vertically to ionospheric altitudes. It is assumed that AGW with these periods can be efficiently excited in the lower atmosphere and play an important role in the dynamic interactions between the lower and upper atmosphere. 相似文献
55.
Russian Journal of General Chemistry - 相似文献
56.
Suslova E. E. Sokolova T. N. Lomova T. N. Zaitseva S. V. Zdanovich S. A. 《Russian Journal of Coordination Chemistry》2003,29(8):540-544
Spectrophotometric and quantum-chemical data showed that (hydroxo)aluminium(III)tetra(4-chloro)phthalocyanine forms one protonated form (trans-dication) in aqueous concentrated H2SO4. The kinetics of the protonated complex dissociation across the Al–N bonds is studied. The effect of the halogen substitution in the aluminium phthalocyanine macrocycle on its basicity and stability is discussed. 相似文献
57.
B. A. Shainyan E. N. Suslova Yu. N. Kokryatskii O. B. Sobolev 《Russian Journal of Applied Chemistry》2012,85(7):1095-1099
Chemistry and aftereffects of the processes proceeding when a refrigerant (ethylene glycol or diethylene glycol) enters galvanic acid baths were studied. 相似文献
58.
O. V. Kosareva M. E. Klyueva T. N. Lomova E. E. Suslova 《Russian Journal of General Chemistry》2005,75(3):461-467
The acid-induced dissociation of copper(II) porphyrin complexes with a high degree of meso- and β-substitution in the ligand was studied. The copper(II) complexes with octaethylporphyrins containing 0, 1, 2, 3, and 4 meso-phenyl substituents were ranked with respect to the stability. Octaβ-alkyl and unsymmetrical meso-phenyl substitution affects not only the quantitative characteristics of dissociation of the complexes but also the kinetic relationships of the process.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 3, 2005, pp. 497–503.Original Russian Text Copyright © 2005 by Kosareva, Klyueva, Lomova, Suslova. 相似文献
59.
Russian Journal of General Chemistry - The DFT and MP2 theoretical conformational analysis of the recently synthesized (1,1′-phenyl-1,1′-silacyclohex-1-yl)disiloxane has revealed the... 相似文献
60.
G. V. Kryshtal' É. P. Serebryakov L. M. Suslova L. A. Yanovskaya 《Russian Chemical Bulletin》1990,39(6):1277-1279
The steric selectivity of the Horner-Emmons reaction between isovaleraldehyde and 3-carboethoxy-2-methyl-2-propenylphosphonates depends on the structure of the alkoxy substituants at the phosphorus atom. The use of five- and six-membered cyclic phosphonates permits us to prepare esters of3,7-dimethyl- 2,4-octadienoic acids with the predominance of the 2Z,4E isomer.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1414–1417, June, 1990. 相似文献