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111.
Muthipeedika Nibin Joy Nikolai Beliaev Tetyana V. Beryozkina Vasiliy A. Bakulev 《Journal of heterocyclic chemistry》2020,57(8):3173-3185
In this paper, we report an efficient and versatile methodology for the synthesis of a series of novel heteroaryl-1,2,3-triazoles connected to 4-methylcoumarin (4-methyl-2H-chromen-2-one) via oxymethylene linker. The desired molecules were accessed by both two-step synthesis and the one-pot copper catalyzed cycloaddition reaction of heteroaromatic azides with coumarin containing acetylenes. The developed protocol was found to be facile and effective for preparing a series of novel heteroaryl-1,2,3-triazole-coumarin conjugates in excellent yields. Practical utility of one-pot protocol has been confirmed by the successful gram-scale synthesis of 1,3-Dimethyl-6-(4-[([4-methyl-2-oxo-2H-chromen-7-yl]oxy)methyl]-1H-1,2,3-triazol-1-yl)pyrimidine-2,4(1H,3H)-dione. 相似文献
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Nataliya Kutsevol Tatyana Zheltonozhskaya Nataliya Melnik Jean-Michel Guenet Vladimir Syromyatnikov 《Macromolecular Symposia》2003,203(1):201-206
Conformational changes have been studied in intramolecular polymer-polymer complexes (intraPC) of graft copolymers of poly(acrylamide) and poly(vinyl alcohol) (PVA-g-PAA) with various numbers of grafts (4-42) per molecule as a function of temperature and copolymer concentration. It is shown that the magnitude of conformational change depends on the grafts content while the temperature range over which the conformation changes occur is essentially determined by copolymer concentration. The conformational changes are reversible on heating and cooling. 相似文献
114.
Natalya Permyakova Tatyana Zheltonozhskaya Nikolay Strilchyk Nina Zagdanskaya Lesya Momot Vladimir Syromyatnikov 《Macromolecular Symposia》2003,203(1):247-258
Complex formation in the model three-component system, including polymer-polymer complex of poly(styrene-alt-maleic acid) (PSMA) and poly(ethylene oxide) (PEO), and also silica sol (SiO2) in aqueous solution as a function of molecular weight of PEO and the order of component mixing, were investigated. The degree of binding of PSMA links with PEO and SiO2 as well as the Gibbs energy of formation of the polymer-polymer complex and polymer-colloid complexes were defined. It was shown that the main factor of stabilization of the structure is hydrogen bonds. The conditions of three-component polymer-colloid system are practically independent of the order of component mixing. The spontaneous formation of polymer-colloid complexes between chemically complementary polymers and small dispersed particles is considered as the main reason for the abnormally high binding ability of colloid particles to the polymer-polymer complex. 相似文献
115.
Ol'ga Demchenko Nataliya Kutsevol Tatyana Zheltonozhskaya Vladimir Syromyatnikov 《Macromolecular Symposia》2001,166(1):117-122
The issue of applying the usual concepts of polymer compatibility to nonstoichiometric PVA/PAA mixtures of chemically complementary poly(vinyl alcohol) and poly(acrylamide), which form in water solution InterPC (intermolecular polymer complex) stabilyzed by H‐bonds, and PAA to PVA graft copolymers (PVA‐PAAN) with different grafted chains number N, that are IntraPC (intramolecular polymer complexes) is discussed. PVA and PAA are compatible on molecular level. At the same time PVA/PAA mixture (50/50 W/W) is characterized by heterogeneous structure consists of InterPC with ϕchar=9gPVA/gPAA and the excess of unconnected PAA. In the case of IntraPC, yet, only PVA‐PAAN, where N=25, is characterized by a single glass transition temperature (Tg). At larger values of N separate PAA domains form giving rise to the corresponding Tg. These results are discussed in view of IntraPC structure peculiarities as a function of N investigated by IR spectroscopy. 相似文献
116.
Vladislav Yu. Kudrya Valeriy M. Yashchuk Ludmila P. Paskal Tetyana B. Zheltonozhskaya Ol'ga V. Demchenko 《Macromolecular Symposia》2001,166(1):249-254
Sorbtion of some impurities from aqueous solutions by polymer complex poly(vinylalcohol) with poly(acrylamide) grafted copolymers (PVA‐PAAN) was studied by means of spectrophotometry and steady‐state fluorescence methods. The experiments showed that the PVA‐PAAN films effectively sorbs impurities molecules of average benzene ring from water. Simultaneously, the processes of polymer films dissolving in water take place. The thermal annealing (with the help of special methods) PVA‐PAAN film gives a possibility to obtain non‐dissolving polymer films which possess high sorbtion ability. Such films are proposed to be used as the sensors with optical response. 相似文献