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61.
Ulf Berg Marcia Berglund Nina Bladh Anette Svensson Magnus Stödeman 《Journal of inclusion phenomena and macrocyclic chemistry》1996,25(1-3):73-76
The properties of inclusion complexes of 1,4-di-R-bicyclo[2.2.2]octaves (R = H (1), Me (2), Cl (3), Br (4), and OH (5)) with cyclodextrins have been studied by NMR, microcalorimetry, and force-field computations. The compounds2 and3 (but not the other compounds) give dynamically stable 1:2 guest-host complexes with -cyclodextrin. Microcalorimetry of5 in water indicates a moderately strong 1:1 complex with - but weak complexes with - or -cyclodextrin. The behaviour depends on the subtle interplay size, polarity, hydrophobicity and type of solvent. 相似文献
62.
Korać Jelena Todorović Nina Zakrzewska Joanna Žižić Milan Spasojević Ivan 《Structural chemistry》2018,29(5):1533-1541
Structural Chemistry - Epinephrine (Epi) is a physiologically important catecholamine. Molecular conformation of Epi controls the interactions with other molecules and its biological effects. There... 相似文献
63.
Kraytsberg Alexander Seizin Nina Ein-Eli Yair 《Journal of Solid State Electrochemistry》2018,22(10):3303-3310
Journal of Solid State Electrochemistry - The behavior of a cubic allotropic modification of tin (α-Sn) towards lithium electrochemical alloying/de-alloying is reported for the first time. The... 相似文献
64.
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66.
Zhamilya K. Sabitova Yulia A. Oskina Nina A. Kolpakova 《Journal of Solid State Electrochemistry》2018,22(12):3717-3723
The phase structure of palladium–bismuth binary electrolytic deposit was studied. The electrodeposition of deposit components on the surface of a graphite electrode (GE) was carried out in situ. On current–voltage curves, the peak of bismuth electrooxidation, the peak of palladium electrooxidation and an additional peak at 0.15 V vs. Ag/AgCl are observed. The peak current at 0.15 V depends both on the concentration of palladium(II) ions and on that of bismuth(III) ions. The thermodynamic theory of alloys in the approximation of the theory of regular solutions was used for calculations. The mixing heat of the binary alloy components and the equilibrium potential of bismuth in the bismuth–palladium alloy are calculated. The calculated equilibrium potential of bismuth in an alloy with palladium is 0.12 V vs. Ag/AgCl which corresponds to the Bi2Pd intermetallic compound (IMC). Investigation of the surface of a GE with a palladium–bismuth deposit with use of scanning electron microscope showed that the electrolytic deposit contains bismuth, palladium and the Bi2Pd IMC. Peak at the potential of plus 0.15 V vs. Ag/AgCl is due to selective bismuth electrooxidation from the Bi2Pd IMC. 相似文献
67.
Bolm C Hildebrand JP Muñiz K Hermanns N 《Angewandte Chemie (International ed. in English)》2001,40(18):3284-3308
Addition and substitution reactions with carbon nucleophiles are fundamental processes in organic synthesis, and the development of general catalytic asymmetric variants thereof is still a major challenge today. In contrast to enantioselective alkyl transfer reactions, the corresponding arylations have not yet reached a high level of maturity. The existing protocols are either of no general applicability or are limited in terms of selectivity. This article summarizes established routes for catalytic asymmetric aryl transfer together with the latest developments in this area. The scope and limitations of this reaction are discussed. 相似文献
68.
Nikolai V. Tsvetkov Mariya E. Mikhailova Nina G. Mikusheva Alexey A. Lezov Alexander S. Gubarev Elena V. Lebedeva 《International Journal of Polymer Analysis and Characterization》2017,22(1):27-34
Conformational and dynamo-optical properties of a homologous series of poly(cetyltrimethylammonium 2-acrylamido-2-methylpropane sulfonates) with molecular masses ranging from 80 to 700?kDa were studied in chloroform solutions by viscometry, dynamic light scattering, sedimentation, and flow birefringence. The Mark–Kuhn–Houwink Equations for this polymer in chloroform were obtained; the values of hydrodynamic diameter and the Kuhn segment length as well as the value of intrinsic anisotropy of polarizability of the monomer unit were defined. 相似文献
69.
Magnesium Hexafluoridozirconates MgZrF6·5H2O,MgZrF6·2H2O,and MgZrF6: Structures,Phase Transitions,and Internal Mobility of Water Molecules 下载免费PDF全文
Andrey V. Gerasimenko Kseniya A. Gaivoronskaya Arseny B. Slobodyuk Nina A. Didenko 《无机化学与普通化学杂志》2017,643(22):1785-1792
The MgZrF6 · n H2O (n = 5, 2 and 0) compounds were studied by the methods of X‐ray diffraction and 19F, MAS 19F, and 1H NMR spectroscopy. At room temperature, the compound MgZrF6 · 5H2O has a monoclinic C‐centered unit cell and is composed of isolated chains of edge‐sharing ZrF8 dodecahedra reinforced with MgF2(H2O)4 octahedra and uncoordinated H2O molecules and characterized by a disordered system of hydrogen bonds. In the temperature range 259 to 255 K, a reversible monoclinic ? two‐domain triclinic phase transition is observed. The phase transition is accompanied with ordering of hydrogen atoms positions and the system of hydrogen bonds. The structure of MgZrF6 · 2H2O comprises a three‐dimensional framework consisting of chains of edge‐sharing ZrF8 dodecahedra linked to each other through MgF4(H2O)2 octahedra. The compound MgZrF6 belongs to the NaSbF6 type and is built from regular ZrF6 and MgF6 octahedra linked into a three‐dimensional framework through linear Zr–F–Mg bridges. The peaks in 19F MAS spectra were attributed to the fluorine structural positions. The motions of structural water molecules were studied by variable‐temperature 1H NMR spectroscopy. 相似文献
70.
Nina Gantert Sebastian Müller Serguei Popov Marina Vachkovskaia 《Journal of Theoretical Probability》2010,23(4):1002-1014
We study survival of nearest-neighbor branching random walks in random environment (BRWRE) on ℤ. A priori there are three
different regimes of survival: global survival, local survival, and strong local survival. We show that local and strong local
survival regimes coincide for BRWRE and that they can be characterized with the spectral radius of the first moment matrix
of the process. These results are generalizations of the classification of BRWRE in recurrent and transient regimes. Our main
result is a characterization of global survival that is given in terms of Lyapunov exponents of an infinite product of i.i.d.
2×2 random matrices. 相似文献