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71.
72.
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
73.
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
74.
75.
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
76.
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
77.
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
78.
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
79.
Sergei Yu Burmistrov Mikhail K. Gratchev Galina I. Kurochkina Larisa K. Vasyanina Edward E. Nifantyev 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract The effect of acid-base properties of amines hydrochlorides (AH) on their catalytic activity in methanolysis of P(III)-N-ethylaniline has been studied. The analysis of Bronsted correlation equation was indicative of general acid catalysis and it was thus confirmed, that general regularities had place during alcoholysis of P(III)-amines under catalysis with AH. In addition, the increasing of alcohol polarity leads to the increasing of proton transfer degree (α) from acid catalysts to phospho(III)amine substrate and to the increasing of the positive charge at the phosphorus in the transition state. Besides, the comparison of α values indicates that in more polar methanol (in comparison with tbutanol) the catalysis is more sensitive to the acidity change of used catalysts. 相似文献
80.
Andrew A. Tolmachev Sergei P. Ivonin Alexandra A. Chaikovskaya Tamara N. Kudrya Tat'jana E. Terekovskaya 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract C-phosphorylation of pyrrole, furan, thiophene derivatives and their benzanalogs by phosphorus tribromide has been studied. Perspective methods for involving trivalent phosphorus residues at a different position of the rings have been developed. Unknown early the heterocycle's derivatives with tri- and tetracoordinated phosphorus substituents (1–5) and novel types of phosphoruscontaining heterocycles (6,7) have been obtained. 相似文献