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Daniel Pinchuk Yosi Kratish Jomon Mathew Lieby Zborovsky Dmitry Bravo‐Zhivotovskii Boris Tumanskii Yitzhak Apeloig 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(22):7513-7517
The first two persistent silenyl radicals (R2C=Si.?R), with a half‐life (t1/2) of about 30 min, were generated and characterized by electron paramagnetic resonance (EPR) spectroscopy. The large hyperfine coupling constants (hfccs) (a(29Siα)=137.5–148.0 G) indicate that the unpaired electron has substantial s character. DFT calculations, which are in good agreement with the experimentally observed hfccs, predict a strongly bent structure (?C=Si?R=134.7–140.7°). In contrast, the analogous vinyl radical, R2C=C.?R (t1/2≈3 h), exhibits a small hfcc (a(13Cα)=26.6 G) and has a nearly linear geometry (?C=C?R=168.7°). 相似文献
35.
L. S. Pinchuk S. V. Zotov V. A. Gol’dade A. V. Vinogradov A. A. Okhlopkov S. A. Sleptsova 《Technical Physics》2000,45(2):179-183
The polarization mechanism of strengthening was studied in thermoplastic polymers filled with ultradisperse powders of refractory SiMeON compounds obtained by plasmachemical synthesis. Thermostimulated depolarization current measurements showed the presence of spontaneous polarization charge in the filler and in filled thermoplastic compositions. Effects of the electric polarization field of the filler particles on the strength and structure of a boundary surface layer in a thermoplastic polymer binder contacting with the filler were studied on model samples. Material in the boundary layer exhibited an increase in the strength and a change in the degree of crystallinity and in the melting temperature. 相似文献
36.
Sergei P. Ivonin Svetlana D. Kopteva Viktor N. Serdyuk Andrei A. Tolmachev Aleksandr M. Pinchuk 《Heteroatom Chemistry》2001,12(7):652-657
This study covers phosphorylation of heterocyclic analogues of N‐methyldiphenylamine with phosphorus tribromide in pyridine solution. The reaction is found to proceed regioselectively in accordance with the orienting effect of the amino group. Mono and bis‐phosphorylated derivatives of the heterocycles have been isolated and characterized. It is pointed out that the heterocyclic systems under study exhibit reduced reactivity in electrophilic phosphorylation as compared to N‐methyldiphenylamine. The results of calculations by the PM3 method are reported for the starting molecules and their σ‐complexes. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:652–657, 2001 相似文献
37.
Marchenko AP Koidan GN Kostyuk AN Tolmachev AA Kapustin EG Pinchuk AM 《The Journal of organic chemistry》2006,71(22):8633-8636
The representative of P,P,P-trichloroylides-5-methyl-2-phenyl-4-(trichlorophosphoranylidene)-2,4-dihydro-3H-pyrazol-3-one-was synthesized. Its constitution was confirmed by 1H, 13C, and 31P NMR spectroscopy and by X-ray analysis. Some chemical properties were studied and compared with ones of P,P,P-trimethylylide-5-methyl-2-phenyl-4-(trimethylphosphoranylidene)-2,4-dihydro-3H-pyrazol-3-one. DFT calculations of the model molecules were carried out. 相似文献
38.
Evgenij V. Zarudnitskii Aleksandr A. Yurchenko Anatolij S. Merkulov Marina G. Semenova Aleksandr M. Pinchuk Andrej A. Tolmachev 《Heteroatom Chemistry》2005,16(7):648-655
The reaction of phosphorus(III) halides with 6‐substituted imidazo[2,1‐b]thiazoles in the presence of bases proceeds regioselectively and affords 5‐phosphinoimidazo[2,1‐b]thiazoles, useful synthons for the preparation of various P(III) and P(V) derivatives. 5‐Phosphinoimidazo[2,1‐b]thiazoles are selectively alkylated at the phosphorus or heterocyclic nitrogen atom, depending on the alkylating agent. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:648–655, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20166 相似文献
39.
Elizaveta Konstantinova Timofey Savchuk Olga Pinchuk Ekaterina Kytina Elizaveta Ivanova Lidiya Volkova Vladimir Zaitsev Alexander Pavlikov Elena Elizarova 《Molecules (Basel, Switzerland)》2022,27(22)
Titania is very famous photocatalyst for decomposition of organic pollutants. Its photocatalytic properties significantly depend on the morphology and chemical composition of the samples. Herein, the TiO2 nanotubes/CuxO nanoheterostructures have been synthesized and the effect of heat treatment performed in molecular atmospheres of air and argon on their photoelectrochemical and photocatalytic properties has been studied. The prepared samples have a higher reaction rate constant compared to TiO2 nanotubes in the decomposition reaction of methylene blue molecules. It is established that in argon treated nanoheterostructures, the copper oxide is present in two phases, CuO and Cu2O, while in air treated ones there is only CuO. In the TiO2 nanotubes/CuxO samples, Cu2+ ions and molecular O2− radicals were detected while in TiO2 nanotubes only carbon dangling bond defects are present. The dynamics of O2− radicals under illumination are discussed. It was shown that the TiO2 nanotubes do not exhibit photocatalytic activity under visible light. The mechanism of the photocatalytic reaction on the surface of the TiO2 nanotubes/CuxO samples was proposed. It is assumed that a photocatalytic decomposition of organic molecules under visible light at the surface of the nanoheterostructures under investigation is realized mainly by the reaction of these molecules with photogenerated O2− radicals. The results obtained are completely original and indicate the high promise of the prepared photocatalysts. 相似文献
40.
Yu. Ya. Fialkov V. M. Pinchuk L. B. Shevardina S. I. Rudneva V. L. Chumak 《Theoretical and Experimental Chemistry》1985,21(3):346-349
Calculations of the spatial and electronic structures of complexes of H+ with pyridine, dimethylaniline, diphenylamine, dimethyl sulfoxide, and propylene carbonate molecules have been carried out. The ion-molecule bonding energies have been determined, and an analysis of the wave functions of the complexes has been carried out. The calculations were carried out by the SCF-MO-LCAO method in the all-valence-electron MINDO/3 approximation. The model has been confirmed by independent conductometric measurements.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 21, No. 3, pp. 362–364, May–June, 1985. 相似文献