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341.
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343.
A new synthetic route was developed to three-module type potential hydrophobic agents, with the molecule consisting of an N-[3-(triethoxysilyl)propyl]amide anchor part (I), a connecting unit formed upon 1,3-propansultone ring cleavage (II), and a polyfluoroheptyloxy functional hydrophobic spacer (III). Proceeding from commercially available polyfluorinated heptanols 1a and 1b and 1,3-propanesultone 3, potassium sulfonates 4a and 4b were prepared. The reaction of 4a and 4b with phosphorus oxychloride resulted in the first synthesis of fluorine-containing sulfonyl chlorides 5a and 5b, which were reacted with 3-aminopropyltriethoxysilane 6 to give the target N-[3-(triethoxysilyl)propyl]-3-(polyfluoroheptyloxy)propane-1-sulfonamides 7a and 7b. The structures of the compounds were proved by NMR spectroscopy, mass spectrometry, and elemental analysis. The studies of their hydrophobizing properties are in progress. 相似文献
344.
Erik Čižmár Daniela Šoltésová Olga N. Kazheva Grigorii G. Alexandrov Andrey V. Kravchenko Lyubov A. Chekulaeva Irina D. Kosenko Igor B. Sivaev Vladimir I. Bregadze Alexey V. Fedorchenko Vladimir A. Starodub Lev I. Buravov Oleg A. Dyachenko Alexander Feher 《Transition Metal Chemistry》2018,43(7):647-655
The synthesis of a radical-cation salt based on a derivative of tetrathiafulvalene, (ET)2[3,3′-Cr(1,2-C2B9H11)2] (ET?=?bis(ethylenedithio)tetrathiafulvalenium), was accomplished by electrochemical anodic oxidation of ET in the presence of (Me4N)[3,3´-Cr(1,2-C2B9H11)2] in the galvanostatic regime. An electric conductivity σ (293 K)?=?7 × 10?3 Ohm?1 cm?1 with semiconductor activation energy Ea???0.1 eV in the range of 127–300 K was observed. The crystal structure of (ET)2[3,3′-Cr(1,2-C2B9H11)2] was determined by X-ray diffraction at 173 K, revealing the presence of structural tetramers in radical-cation stacks. The magnetic properties of the complex were investigated in the temperature range 1.8–300 K using magnetometry and EPR, showing that the magnetic structure of (ET)2[3,3′-Cr(1,2-C2B9H11)2] consists of two independent magnetic subsystems. Cation radicals form a rectangular magnetic lattice in the ab-plane with significant antiferromagnetic exchange interactions. The chromium bis(dicarbollide) anions are characterized by unusually strong positive zero-field splitting of the Cr(III) ions, which was confirmed by ab initio calculations. 相似文献
345.
V. D. Dyachenko O. S. Bityukova A. D. Dyachenko O. V. Shishkin 《Russian Journal of General Chemistry》2011,81(5):944-955
Reaction of cyanoacetanilides with 3,3-bis(methylthio)-2-cyano-N-arylacrylamides proceeds to form isomeric N,1-diaryl-1,6-dihydropyridine-3-carboxamides. A single crystal consisting of 2-amino-4-methylthio-N-(2-methoxyphenyl)-6-oxo-1-phenyl-5-cyano-1,6-dihydropyridine-3-carboxamide and 2-amino-4-methylthio-1-(2-methoxyphenyl)-6-oxo-N-phenyl-5-cyano-1,6-dihydropyridine-3-carboxamide was studied by XRD. 相似文献
346.
V. D. Dyachenko O. S. Bityukova A. D. Dyachenko 《Russian Journal of Organic Chemistry》2011,47(9):1335-1340
New functionally substituted 2-oxo- and 2-thioxonicotinic acid amides and nitriles were synthesized by condensation of 3,3-bis(methylsulfanyl)acrylonitriles
with CH acids according to the SNVin pattern. 相似文献
347.
The condensation of 1-acyl-2-(morpholin-4-yl)cycloalkenes with 3-amino-1-phenyl-1H-pyrazol-5(4H)-ones gave the corresponding 2,3,6,7,8,9-hexahydropyrazolo[3,4-c]isoquinoline and 3,6,7,8,9,10-hexahydrocyclohepta[ d]pyrazolo[3,4-b]pyridine derivatives. Alkylation of 2,3,6,7,8,9-hexahydropyrazolo[3,4-c]-isoquinolines with alkyl halides occurred at the nitrogen atom in the 3-position. The structure of 7-methyl-2,5-diphenyl-2,3,6,7,8,9-hexahydro-1H-pyrazolo[3,4-c]isoquinolin-1-one was proved by X-ray analysis. 相似文献
348.
Periodic traveling waves are numerically computed in a constant vorticity flow subject to the force of gravity. The Stokes wave problem is formulated via a conformal mapping as a nonlinear pseudodifferential equation, involving a periodic Hilbert transform for a strip, and solved by the Newton‐GMRES method. For strong positive vorticity, in the finite or infinite depth, overhanging profiles are found as the amplitude increases and tend to a touching wave, whose surface contacts itself at the trough line, enclosing an air bubble; numerical solutions become unphysical as the amplitude increases further and make a gap in the wave speed versus amplitude plane; another touching wave takes over and physical solutions follow along the fold in the wave speed versus amplitude plane until they ultimately tend to an extreme wave, which exhibits a corner at the crest. Touching waves connected to zero amplitude are found to approach the limiting Crapper wave as the strength of positive vorticity increases unboundedly, while touching waves connected to the extreme waves approach the rigid body rotation of a fluid disk. 相似文献
349.
We study the stability of Stokes waves in an ideal fluid of infinite depth. The perturbations that are either coperiodic with a Stokes wave (superharmonics) or integer multiples of its period (subharmonics) are considered. The eigenvalue problem is formulated using the conformal canonical Hamiltonian variables and admits numerical solution in a matrix-free manner. We find that the operator matrix of the eigenvalue problem can be factored into a product of two operators: a self-adjoint operator and an operator inverted analytically. Moreover, the self-adjoint operator matrix is efficiently inverted by a Krylov-space-based method and enjoys spectral accuracy. Application of the operator matrix associated with the eigenvalue problem requires only flops, where N is the number of Fourier modes needed to resolve a Stokes wave. Additionally, due to the matrix-free approach, storage for the matrix of coefficients is no longer required. The new method is based on the shift-invert technique, and its application is illustrated in the classic examples of the Benjamin–Feir and the superharmonic instabilities. Simulations confirm numerical results of preceding works and recent theoretical work for the Benjamin–Feir instability (for small amplitude waves), and new results for large amplitude waves are shown. 相似文献