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91.
Michael A. Pudovik Lyudmila Kibardina Alexey Trifonov Alexey Dobrynin Sergei Katsyuba Alexander Burilov 《Phosphorus, sulfur, and silicon and the related elements》2019,194(1-2):120-126
New O-phosphorylated pyridoxal derivatives have been synthesized through the reaction of azomethines with РV acid chlorides. 2-Chloro-2-thioxo-5,5-dimethyl-1,3,2-dioxaphosphinanes and diethylchlorothiophosphate have been employed as phosphorylating agents. Regardless of the nature of the phosphorylating agent, the reaction is regioselective at phenolic hydroxyl group. The structure of final products is determined by the nature of the substituent at the nitrogen atom. If R is alkyl or cycloalkyl group, the products of the reaction represent phosphorylated pyridoxal imines, whereas phosphorylated furopyridines are formed in the case R is aryl substituent. 相似文献
92.
Belyaev B. A. Tyurnev V. V. Voloshin A. S. Leksikov An. A. Galeev R. G. Shabanov V. F. 《Doklady Physics》2020,65(9):343-348
Doklady Physics - The design of a multilayer bandpass filter has been investigated, in which each of the half-wavelength resonators consists of two dielectric layers with outer strip conductor... 相似文献
93.
94.
Gated Channels and Selectivity Tuning of CO2 over N2 Sorption by Post‐Synthetic Modification of a UiO‐66‐Type Metal–Organic Framework 下载免费PDF全文
Alexander Kronast Sebastian Eckstein Dr. Peter T. Altenbuchner Dr. Konrad Hindelang Dr. Sergei I. Vagin Prof. Dr. Bernhard Rieger 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(36):12800-12807
The highly porous and stable metal–organic framework (MOF) UiO‐66 was altered using post‐synthetic modifications (PSMs). Prefunctionalization allowed the introduction of carbon double bonds into the framework through a four‐step synthesis from 2‐bromo‐1,4‐benzenedicarboxylic acid; the organic linker 2‐allyl‐1,4‐benzenedicarboxylic acid was obtained. The corresponding functionalized MOF (UiO‐66‐allyl) served as a platform for further PSMs. From UiO‐66‐allyl, epoxy, dibromide, thioether, diamine, and amino alcohol functionalities were synthesized. The abilities of these compounds to adsorb CO2 and N2 were compared, which revealed the structure–selectivity correlations. All synthesized MOFs showed profound thermal stability together with an increased ability for selective CO2 uptake and molecular gate functionalities at low temperatures. 相似文献
95.
In the present paper, the method of guiding functions is applied to study the periodic problem for a differential inclusion with a causal multioperator. At first we consider the case when the multioperator is closed and convex-valued. Then the case of a non-convex-valued and lower semicontinuous right-hand part is considered. Thereafter, the theory is extended to the case of non-smooth guiding functions. 相似文献
96.
97.
Chapyshev Sergei V. Korchagin Denis V. Ganin Yuri V. Ushakov Evgeny N. 《Chemistry of Heterocyclic Compounds》2017,53(6-7):786-790
Chemistry of Heterocyclic Compounds - Nucleophilic substitution of fluorine atoms in 2,3,5,6-tetrafluoropyridine-4-carbonitrile with sodium azide was used to obtain... 相似文献
98.
Tony Chave Sergei I. Nikitenko Dominique Granier Thomas Zemb 《Ultrasonics sonochemistry》2009,16(4):481-487
Herein, we report the sonochemical reactions with MSU-X mesoporous alumina (m-Al2O3) in aqueous solutions. Sonication (f = 20 kHz, I = 30 W cm?2, Waq = 0.67 W mL?1, T = 36–38 °C, Ar) causes significant acceleration of m-Al2O3 dissolution in the pH range of 4–11. Moreover, power ultrasound has a dramatic effect on the textural properties and phase composition of m-Al2O3. Short-time sonication at pH = 4 leads to the formation of nanorods and nanofibers of boehmite, AlO(OH). Prolonged ultrasonic treatment causes high aspect morphology transformation to aggregated nanosheets in weakly acid solutions or plated nanocrystals in alkaline solutions. Sonochemical products in alkaline medium are composed principally from boehmite and small amounts of bayerite, Al(OH)3. Silent hydrolysis of m-Al2O3 yields boehmite at pH = 4 and bayerite at pH = 11. The effect of ultrasound on the textural properties of mesoporous alumina as well as on the transformation of nanosized bayerite to boehmite can be consistently attributed to the transient strong heating of the liquid shell surrounding the cavitation bubble which caused the chemical processes similar to those occurred during hydrothermal treatment. 相似文献
99.
Aleksandr N. Kostyuk Nikolai V. Lysenko Sergei I. Dovgopoly Andrei A. Tolmachev 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1)
Abstract Introduction of benzylidene group at α-position of enamines derived from cyclic ketones substantially increases strength of C-P bond thus permitting further syntheses without splitting of the C-P bond. A wide set of phosphorylated derivatives of type (I) were prepared and their properties were studied. Combination of an enamine moiety with other nucleophilic centers such as C or N in a molecule allows to carry out cyclisation giving five- and six-membered phosphorus-containing heterocycles of types (II, III). 相似文献
100.
George N. Nikonov Anna S. Balueva Elvira I. Musina Katherine V. Kovalenko Sergei V. Bobrov 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):821-823
The methods of synthesis and space structure of phosphorus-containing compounds, in which stacking conformation is realized, are considered. It is shown that intramolecular stacking can be observed in monoheterocyclic compounds, bi-and polycyclic compounds, complexes of metals and acyclic compounds. 相似文献