排序方式: 共有62条查询结果,搜索用时 15 毫秒
21.
Alexey N. Egorochkin Olga V. Kuznetsova Nadiya M. Khamaletdinova Yury A. Kurskii Lada G. Domratcheva‐Lvova Georgy A. Domrachev 《Magnetic resonance in chemistry : MRC》2009,47(9):782-790
The literature data on substituent influence on the 51V, 55Mn, 57Fe, 59Co, 61Ni, 95Mo, 103Rh, 183W, 187Os and 195Pt NMR chemical shifts (δ) and on J (M, P; M = Mn, Fe, Mo, Rh, W, Os) coupling constants have been analyzed for 30 series of the organometallic complexes. It has been established for the first time that the δ and J values depend on the inductive, resonance and polarizability effects of substituents. The polarizability effect is caused by the partial charge on the central M atom. The contribution of this effect ranges from 3 to 86%. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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Alexey N. Egorochkin Olga V. Kuznetsova Nadiya M. Khamaletdinova Lada G. Domratcheva‐Lvova 《Magnetic resonance in chemistry : MRC》2012,50(1):40-51
The literature data on substituent influence on the nuclear quadrupole resonance frequencies (ν), quadrupole coupling constants (e2Qq ? h? 1), and asymmetry parameters (η) for 36 series of the H‐complexes, charge–transfer complexes, transition metal complexes and other donor–acceptor complexes have been considered, using the correlation analysis. Generally the ν, e2Qq ? h? 1, and η values were first established to depend on the inductive, resonance, polarizability, and steric effects of substituents. The presence or otherwise of certain effects as well as relation between their contributions are determined by the type of series. The polarizability effect owes its existence to the appearance of an excess charge on the indicator centre as a result of the complexation. The contribution of this effect ranges up to 75%. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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Eskandar Kolvari Mohammad Ali Zolfigol Nadiya Koukabi Maryam Gilandust Abdol-Vahid Kordi 《Journal of the Iranian Chemical Society》2013,10(6):1183-1191
An environmentally friendly method is described for the preparation of substituted quinoline and quinoxaline derivatives using Zr(OTf)4 as an efficient catalyst. The method is based on using 1,3-diketones, ketones and 2-aminoaryl ketones under solvent-free conditions and also on using 1,2-diketone, 1,2-diamine in EtOH/H2O at room temperature for quinloine and quinoxaline synthesis, respectively. The advantages in using this method, include its environmental friendliness, simple operating process and good yields. 相似文献
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A simple and efficient procedure for the synthesis of iodoarenes is developed which involves the sequential diazotization–iodination of aromatic amines with sodium nitrite, nanomagnetic supported sulfonic acid, and potassium iodide under solvent-free conditions at room temperature. 相似文献
25.
Agasti SS Caldwell ST Cooke G Jordan BJ Kennedy A Kryvokhyzha N Rabani G Rana S Sanyal A Rotello VM 《Chemical communications (Cambridge, England)》2008,(35):4123-4125
Three generations of water-soluble flavin dendrons have been synthesized and the role dendrimer generation has on the physical and catalytic properties of these assemblies has been investigated. 相似文献
26.
Aleksandra A. Chaikovskaya Yurii V. Dmytriv Nadiya V. Shevchuk Radomyr V. Smaliy Aleksander M. Pinchuk Andrey A. Tolmachev 《Heteroatom Chemistry》2009,20(4):235-239
A N → C3 migration of the dichlorophosphino group has been revealed in the phosphorylation of unsubstituted indole with phosphorus trichloride. Several 3‐phosphorylated NH‐indole derivatives have thus been obtained and N‐acylation of one of the products has been performed. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:235–239, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20540 相似文献
27.
Sydorenko N Zificsak CA Gerasyuto AI Hsung RP 《Organic & biomolecular chemistry》2005,3(11):2140-2144
Total syntheses of indoloquinolizidine alkaloid (+/-)-, R-(+)-, and S-(-)-deplancheine are described here. The synthesis features an enantioselective intramolecular formal aza-[3 + 3] cycloaddition for the construction of the quinolizidine CD-ring. This application serves to introduce a new synthetic strategy for the synthesis of indoloquinolizidine alkaloids. 相似文献
28.
Belyakova LA Besarab LN Roik NV Lyashenko DY Vlasova NN Golovkova LP Chuiko AA 《Journal of colloid and interface science》2006,294(1):11-20
Silicas chemically modified with attached aminopropyl, imidazolyl, and trimethylsilyl groups, with adsorptive and coordinative grafted hemin were synthesized. Adsorption of some bile acids on the surface of hydroxylated silica, synthesized siliceous adsorbents and cholestyramine has been studied. It was found that the main contribution to the total adsorption is caused by electrostatic attraction between anions of bile acids and positively charged sites of the surface of modified silica and also by dispersion interactions between steroid skeleton of bile acids and functional groups of modified silicon dioxides. It was established that the kinetic parameters of adsorption and adsorptive capacity for all investigated siliceous adsorbents exceed similar characteristics for cholestyramine. The best of synthesized adsorbents is hemin-containing adsorbent IX, and the sequence of increase in its adsorptive capacity in relation to bile acids corresponds to the following series: I < III < II, IV < VI < V < VIII < VII < IX. 相似文献
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