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121.
Based on density functional calculations, the mechanism and the energetic course of the chemical vapor deposition (CVD) reaction of TiCl4 with NH3 were studied at the level of B3LYP with 6-311g(d) basis set. Furthermore, the polymerization processes of dimerization, trimerization and tetramerization were investigated. The calculation results indicate that the formation of polymers is favored at the elimination reaction. On the basis of the calculated energetics, a possible mechanism of the reduction reaction has been proposed. 相似文献
122.
Glukhareva T. V. Morzherin Yu. Yu. Dyudya L. V. Malysheva K. V. Tkachev A. V. Padva A. Bakulev V. A. 《Russian Chemical Bulletin》2004,53(6):1311-1317
A method for the synthesis of previously inaccessible 5-dialkylamino-substituted 1,2,3-thiadiazole-4-carbaldehydes was developed. Ring transformation in these compounds induced by primary aliphatic and aromatic amines, hydroxylamines, and N-substituted hydrazines resulted in the synthesis of a broad range of 1,2,3-triazole-4-carbothioamide. 相似文献
123.
The kinetics of electroreduction of Pd(II) complexes with -alanine, Pd(ala)2, is studied on a rotating Pd disk electrode in solutions of pH 8–13 containing large excess of -alanine and various supporting electrolytes (NaF, Na2SO4, NaClO4). On a Pd electrode, complexes Pd(ala)2 undergo reduction at potentials much more negative than on an Hg electrode. This is attributed to the chemisorption of water on the Pd electrode, which hampers adsorption of Pd(ala)2 that take part in the slow electrochemical stage. As with the Hg electrode, perchlorate ions hinder the Pd(ala)2 reduction on a Pd electrode. Studying adsorption of Pd(ala)2 on a Pd electrode is hampered by parallel processes of hydrogen adsorption and absorption. 相似文献
124.
在358K下用200ml/min的空气氧化碱性悬浮液合成了MFe_2O_(4+δ)(δ≥0,M=Fe、Co、Ni、Mn),并在573K下用40ml/min的H_2还原MFe_2O_(4+δ)制备了氧缺位铁酸盐MFe_2O_(4-δ)(δ>0)。用XRD、Mssbauer谱等测试方法对铁酸盐的结构进行了表征,考察了铁酸盐的组成及第二金属组分(Co、Ni、Mn)对铁酸盐还原性能的影响。在H_2还原3h内,铁酸盐氧缺位程度随还原时间增加而增大,晶格常数也相应增大;5h以上,铁酸盐将被还原为MO-FeO或α-Fe,晶格常数几乎不变。按Fe、Co、Ni、Mn顺序,MO与FeO的相互作用能力、MO-FeO固溶体的稳定性及铁酸盐还原为MO-FeO的能力均增强,MO-FeO进一步还原为α-Fe的能力却减弱。 相似文献
125.
Fedushkin I. L. Nevodchikov V. I. Bochkarev M. N. Dechert S. Schumann H. 《Russian Chemical Bulletin》2003,52(1):154-159
Reduction of 2,5-di-tert-butylcyclopentadienone with two equivalents of thulium diiodide in tetrahydrofuran afforded the binuclear thulium(iii) complex with the cyclopentadienyl oxide ligand, viz., TmI2(THF)2[5-But
2C5H2O]TmI2(THF)3 (1). Shielding of the carbonyl carbon atom with two tert-butyl substituents prevents pinacolization of the ketyl radical anions that formed upon one-electron reduction of cyclopentadienone. The reaction of thulium diiodide with an excess of pyridine in tetrahydrofuran gave a product of reductive coupling of two pyridine radical anions, viz., [TmI2(C5H5N)4]2(2-N2C10H10) (2). The structures of complexes 1 and 2 were established by single-crystal X-ray diffraction analysis. 相似文献
126.
Scientific research training is an essential part of undergraduate learning, which plays an important role in improving students' knowledge utilization and scientific literacy. Taking the participation process of "Energy conservation and emission reduction competition" as an example, this paper briefly introduces the undergraduate scientific research training of students majoring in polymer materials and engineering from their own perspective, and the way to combine the discipline and school characteristics to reflect the thinking of engineering students in scientific research and practical application. 相似文献
127.
A convenient and efficient preparation of Stryker's reagent, [Ph3PCuH]6, under homogeneous conditions using silanes as the reducing agent is detailed. The reaction time can be reduced to 1-2 h, and high yields of Stryker's reagent can be routinely achieved. The same method has been extended to the synthesis of [Ph3PCuD]6 using Ph2SiD2. 相似文献
128.
LI Chun-Bao Chen Yi LI Song-Lin ZHANG Wen-Qin CUI Yi JI Xiu-Jie ZHENG Peng-Wu 《结构化学》2002,21(5):470-472
1 INTRODUCTION (9S,13R,14S)-7,8-Didehydro-3,7-dimethoxy-4-hydroxy-17-methylmorphinan-6-one I is an impor- tant natural product that was used to ease pain, decrease blood pressure and diminish inflammation. In order to study the stereochemistry of the reduction of I with potassium boronhydride, the crystal structure of the title compound II was determined by X-ray diffraction method. 2 EXPERIMENTAL 2. 1 Instrument The melting point was measured on a Yanagimoto MP-500 apparatus… 相似文献
129.
Sizov A. I. Zvukova T. M. Belsky V. K. Bulychev B. M. 《Russian Chemical Bulletin》2001,50(11):2200-2202
The heterometallic zirconocene(iii) aluminum hydride complex (Cp2ZrH)2HAlCl2·C4H8O2·C6H6 was synthesized by reduction of Cp2ZrCl2 with lithium aluminum hydride in the presence of Cp2TiBH4 and 1,4-dioxane, and its structure was established by X-ray diffraction analysis. 相似文献
130.
Bartelt等 [1] 于 1 989年首次从穆勒果蝇 (Drosophila mulleric)的雄性成虫体内分离出其聚集信息素 ,并确证其主要生物活性的成分为 (S) -构型的 2 -乙酰氧基十三烷 (1 ) ,而 (R) -构型无生物活性 .1 999年Hillbur等 [2 ,3 ] 发现碗豆瘿蚊 (Contarinia pisi)的雌性性信息素主要成分中也含有 (1 ) ,其对碗豆瘿蚊雄虫具有很强的性引诱作用 .有关 (1 )的合成报道较多的为酶促反应合成法 [4~ 7] .我们曾以 1 -苯砜基 - 2 -丙酮为原料经酶促还原反应合成了目标产物 ,此法尽管合成路线短 ,光学产率较高 ,但反应原料不易购得 ,且使用两摩尔比… 相似文献