94 research outputs found
Synthesis of Regular Polyhexene in Perfluoromethylcyclohexane
This work was supported by the Russian Science Foundation (Ref. № 18-13-00365)
Synthesis of 5-Methyl-1,2,4-Triazolo[1,5-а]Pyrimidin-7(4H)-One-a Semi-Product of the Synthesis of Antiviral Drug Triazide® in the Conditions of Microwave Excitation
This work was supported by the Russian Science Foundation (Ref. № 18-13-00365)
Hemilability of phosphine-thioether ligands coordinated to trinuclear Mo3S4 cluster and its effect on hydrogenation catalysis
Ligand-exchange reactions of [Mo3S4(tu)8(H2O)]Cl44H2O (tu = thiourea) with
(PhCH2CH2)2PCH2CH2SR ligands, where R = Ph (PS1), pentyl (PS2) or Pr (PS3) afford new
complexes isolated as [Mo3S4Cl3(PS1)3]PF6 ([1]PF6), [Mo3S4Cl3(PS2)3]PF6 ([2]PF6) and
[Mo3S4Cl3(PS3)3]PF6 ([3]PF6) salts in 30-50% yields as the major reaction products. The crystal
structures of [1]PF6 and [2]PF6 were determined by X-ray diffraction (XRD) analysis. Each of
the three phosphine-thioether ligands is coordinated in a bidentate chelating mode to a different
molybdenum atom of the Mo3S4 trinuclear cluster, herewith all the phosphorus atoms of the
phosphino-thioether ligand are located trans to the capping sulfur (3-S). A second product that
forms in the reaction of [Mo3S4(tu)8(H2O)]Cl44H2O with PS1 corresponds to the neutral
[Mo3S4Cl4(PS1)2(PS1*)] complex. Its XRD analysis reveals both bidentate (PS1) and
monodentate (PS1*) coordinating modes of the same ligand. In the latter mode the phosphinethioether
is coordinated to a Mo atom only via the P atom. All compounds were characterized by
1H, 31P{1H} NMR, electrospray-ionization (ESI) mass spectrometry and cyclic voltammetry
(CV). Reactions of [1]PF6, [2]PF6 and [3]PF6 with an excess of Bu4NCl in CD2Cl2 were followed
by 31P{1H} NMR. The spectra indicate equilibrium between cationic [Mo3S4Cl3(PSn)3]
+
and
neutral [Mo3S4Cl4(PSn)2(PSn*)] (n = 1, 2) species. The equilibrium constants were determined
as 2.5 ± 0.2103
, 43 ± 2 М
-1
and 30 ± 2 М
-1
(at 25°C) for [1]PF6, [2]PF6 and [3]PF6, indicating
quantitative differences in hemilabile behavior of the phosphino-thioether ligands, depending on
the substituent at sulfur. Clusters [1]PF6, [2]PF6 and [3]PF6 were tested as catalysts in reduction
of nitrobenzene to aniline with Ph2SiH2 under mild conditions. Significant differencies in the
catalytic activity were observed, which can be attributed to different hemilabile behavior of the
PS1 and PS2/PS3 ligands
ЭКСПЕДИЦИОННЫЕ РАДИОЭКОЛОГИЧЕСКИЕ ИССЛЕДОВАНИЯ В ЯПОНСКОМ МОРЕ И СЕВЕРО-ЗАПАДНОЙ ЧАСТИ ТИХОГО ОКЕАНА ПОСЛЕ АВАРИИ НА ЯПОНСКОЙ АЭС «ФУКУСИМА-1»: ПРЕДВАРИТЕЛЬНЫЕ РЕЗУЛЬТАТЫ
In the period from April 22 until May 20, 2011, an expedition aboard the research vessel “Pavel Gordienko” (Russian Federation) was carried out to the Sea of Japan and the Kuril-Kamchatka region of the Pacific Ocean. The main aim of the expedition was to study radioactive contamination of the atmospheric air and sea water after the accident at the NPP “Fukushima-1” in Japan. This paper provides preliminary results on the activity concentration of 137Cs and 134Cs in twenty four samples of sea water. The activity concentrations of 131I, 137Cs, 134Cs, and 7Be for twenty nine samples of atmospheric aerosols, which were sampled during the expedition, are also given. Despite the preliminary character of the results of this study, a generic conclusion on a negligible radiological impact of the anthropogenic gamma-ray-emitting radionuclides for the Far-Eastern sea areas of Russia can be reached. The investigations have been supported by a grant from the Russian Geographical Society.В период с 22 апреля по 20 мая 2011 г. на научно-исследовательском судне «Павел Гордиенко» (Российская Федерация) было проведено экспедиционное обследование Японского моря и Курило-Камчатского района Тихого океана. Основной целью экспедиции являлось исследование радиоактивного загрязнения воздушной и водной среды после аварии на АЭС «Фукусима-1» в Японии. В данной статье представлены предварительные результаты оценки содержания 137Cs и 134Cs в двадцати четырех пробах морской воды. Кроме этого, даны результаты определения содержания 131I, 137Cs, 134Cs, и 7Be в двадцати девяти пробах атмосферных аэрозолей, отобранных в рейсе. Несмотря на предварительный характер полученных результатов, проведенные исследования позволяют прийти к общему заключению о пренебрежимо малом влиянии изученных техногенных гамма-излучающих радионуклидов на радиационную обстановку в районах российского побережья Дальнего Востока. Грант на проведение исследований был выделен Попечительским советом Русского географического общества
QUANTITATIVE DETERMINATION OF VITAMINS A, D3 AND E IN PREMIXES «MAUERVIT» AND «GRANDVITAM» BY ULTRA HPLC
A convenient method for analyzing the content of vitamins A, D3 and E in premixes has been developed (the tests were carried out using the example of the premixes «Mauervit» and «randvitam») using ultra HPLC. The necessary changes of the procedure have been made in comparison with the ones presented previously in GOST R 50928-96 due to the presence in the premix components hampering analysis (in particular, Tween 80). The developed procedure has been tested in terms of specificity, accuracy and precision. In addition, the possibility of using a simpler procedure for the analysis of vitamins extract, used as raw material for premix production, has been demonstrated
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