排序方式: 共有41条查询结果,搜索用时 701 毫秒
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M.?V.?LobanovEmail author E.?B.?Pomakhina A.?I.?Rebrov A.?L.?Krasovskiy A.?A.?Yaroslavov K.?A.?Shashkeev B.?Ph.?Pavlyuk 《Russian Journal of Applied Chemistry》2018,91(1):40-48
A simple method that was used to obtain stabilized ZnO nanoparticles and their dispersions in water is presented. It yields anisotropic (trigonal prismatic) nanocrystals with dimensions below 50 nm. The Partial Profile Relaxation (PPR) technique was applied in the analysis of X-ray diffraction data with complex anisotropic broadening. Ethylene diamine catalyzed silanization was utilized for the covalent surface functionalization, which allowed us to obtain stable waterborne dispersions when aminosilanes were used. The difference in the surface structure of ZnO nanoparticles for different variants of functionalization was investigated by 29Si NMR spectroscopy. The combination of X-ray diffraction and dynamic light scattering data indicates minimal degree of particle agglomeration in the dispersions. 相似文献
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V. G. Krasovskiy E. A. Chernikova L. M. Glukhov G. I. Kapustin A. A. Koroteev 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2018,92(12):2379-2385
Two series of imidazolium ionic liquids with the bis(trifluoromethylsulfonyl)imide anion were synthesized, which differ by the presence of a hydroxyl group at the ω-position of the alkyl substituent in the cation structure (nC = 2–8). The properties of the liquids were studied by DSC, TGA, and IR and NMR spectroscopy. Their thermal stability was studied, and the melting points, viscosity, and volatility in vacuum were measured. The effect of OH groups in the structure of the ionic liquid on its properties was evaluated. 相似文献
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Despotopoulou C Bauer RC Krasovskiy A Mayer P Stryker JM Knochel P 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(8):2499-2506
A single Br/Mg exchange of 1,2-dibromocyclopentene with iPrMgCl LiCl provides the corresponding beta-bromocyclopentenylmagnesium reagent, which can then be reacted with various electrophiles (yields: 65-82 %). In the presence of a secondary alkylmagnesium halide and Li2CuCl4 (2 mol %), these 2-bromoalkenylmagnesium compounds undergo bromine substitution and can then further react with electrophiles to give 1,2-difunctionalised cyclopentenes (63-79 %). The mechanism of this process is discussed. 相似文献
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Deyko A Hessey SG Licence P Chernikova EA Krasovskiy VG Kustov LM Jones RG 《Physical chemistry chemical physics : PCCP》2012,14(9):3181-3193
The enthalpies of vaporisation, Δ(vap)H(298), of seven ionic liquids (ILs) (four imidazoliums, a pyridinium, a phosphonium and an isouronium) have been determined by temperature programmed desorption using line of sight mass spectrometry. They were: 1-ethyl-3-methylimidazolium bis(pentafluoroethyl)phosphinate, [C(2)C(1)Im][PO(2)(C(2)F(5))(2)]; 1-butyl-3-methylimidazolium octylsulfate, [C(4)C(1)Im][C(8)OSO(3)]; 1-butyl-3-methylimidazolium tetrafluoroborate, [C(4)C(1)Im][BF(4)]; 1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate, [C(6)C(1)Im][FAP]; 1-butylpyridinium methylsulfate, [C(4)Py][C(1)OSO(3)]; trihexyl(tetradecyl)phosphonium tetrafluoroborate, [P(6,6,6,14)][BF(4)] and O-ethyl-N,N,N',N'-tetramethylisouronium trifluoromethanesulfonate, [C(2)(C(1))(4)iU][TfO]. The values were found to be consistent with a previously proposed, predictive, model in which Δ(vap)H(298) is decomposed into a Coulombic component (computable from the IL density) and van der Waals components from the anion and cation. Two previously predicted values of Δ(vap)H(298) were found to be within 6 kJ mol(-1) of the measured experimental values. Values for the van der Waals components are tabulated for eleven cations and twelve anions. Predictions are made for Δ(vap)H(298) for 13 ILs with as yet unmeasured Δ(vap)H(298) values (using experimental molar volumes), and for a further 44 ILs using estimated molar volumes. 相似文献
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Acyclic functionalized alkenyl iodides are converted with high stereoselectivity to the corresponding functionalized alkenylmagnesium derivatives by the reaction with i-PrMgCl.LiCl between -40 and -20 degrees C. Functional groups such as a nitrile, chloride, iodide, and ester are readily tolerated. The conversion of an alkenyl iodide bearing a keto group to the corresponding silylated cyanohydrin allows preparation of the corresponding Grignard reagent affording, after acylation and deprotection, unsaturated 1,4-diketones. 相似文献