Aqueous Knoevenagel Condensation Catalyzed by Aminopropyl-functionalized MCM-41

Since much more attention has been paid to the sustainable development, many researchers try to improve conventional chemical process and find new and more, environmentally friendly routes1. Aqueous-phase reactions are of interest as environ- mentally ben…     

红紫素-18酰亚胺衍生物的合成及其可见光谱的研究

选择脱镁叶绿酸 a甲酯为原料进行 3 位化学修饰和E环改造 .经 3 乙烯基的溴化氢加成和与联苯酚的亲核取代反应 ,完成了 3 位联苯氧基的引入 ;在碱性条件下 ,通过空气氧化将E环转变为环己二羧酸酐形成红紫素 18甲酯衍生物 ;所得氧化产物进而和盐酸羟胺反应 ,经胺解开环和再缩合成环构成N 羟基红紫素 18酰亚胺衍生物 ;对其羟基进行烷基化和酰基化 ,合成出N 取代红紫素 18酰亚胺衍生物 .同时讨论了化学结构变化对分子可见光谱的影响 .所合成新化合物的结构均经UV ,IR ,1 HNMR光谱和元素分析予以确认     

DFT computational study of the mechanism of allyl halides carbonylation catalyzed by nickel tetracarbonyl

A theoretical investigation at the DFT(B3LYP) level on the carbonylation reaction of allyl bromide catalyzed by nickel tetra-carbonyl Ni(CO)(4) is discussed. The computational results show the following: (i) Three main steps characterize the catalytic cycle: (a) an oxidative addition step, (b) a carbonylation step, and (c) a reductive elimination step where the acyl product is obtained and the catalyst is regenerated. (ii) Both Ni(CO)(3) and Ni(CO)(4) complexes can behave as "active" catalytic species. (iii) The oxidative addition leads to the formation of either eta(3) or eta(1)-allyl nickel complexes, which are involved in a fast equilibrium. (iv) The carbonylation occurs much more easily on the eta(1) than on the eta(3) intermediates.     

The benzene ring as a dipolarophile: Reactions of monosubstituted benzenes with tetracyanoethylene oxide

Summary The reaction of tetracyanoethylene oxide on one hand and toluene, chlorobenzene, fluorobenzene, anisole, and nitrobenzene, on the other, has been studied. Toluene and the halogenobenzenes yield mixtures of monoadducts, anisole yieldp-methoxyphenylmalononitrile and its dimer and nitrobenzene does not react. These results are discussed with the help of a qualitative orbital model.¹H-NMR analysis of some monoadducts has been carried out.

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Der Benzolring als Dipolarophil: Reaktionen monosubstituierter Benzole mit Tetracyanoethylenoxid

Zusammenfassung Es wurden die Reaktionen von Tetracyanoethylenoxid mit Toluol, Chlorbenzol, Fluorbenzol, Anisol und Nitrobenzol untersucht. Toluol und die Halogenbenzole ergaben Mischungen von Monoaddukten, Anisol ergabp-Methoxyphenylmalononitril und sein Dimer, Nitrobenzol zeigte keine Reaktion. Diese Resultate werden mit Hilfe eines qualitativen Orbitalmodells diskutiert. Die Analyse einiger Monoaddukte erfolgte mittels¹H-NMR-Analyse.

     

Mechanistic aspects of the Wolff-Kishner reaction. V. The cation effect on the reaction of benzophenone hydrazone in butyl carbitol and decyl alcohol

The rate of the Wolff-Kishner reaction of benzophenone hydrazone in butyl carbitol increases as the cation of the alkoxide base is varied in the order K>Na>Li>Mg. The replacement of butyl carbitol by 1-decanol also accelerates the reaction, and an additional increase is caused by the presence of crown ether. On the basis of changes in the activation parameters, it is concluded that the reactivity of the hydrazone anion increases as the contact ion pair becomes more fully solvated and dissociated.     

Substituted m-phenylene bridges as strong ferromagnetic couplers for Cu(II)-bridge-Cu(II) magnetic interactions: new perspectives

Based on a combined theoretical-experimental study, we propose that substituted m-phenylene ligands (m-N-Phi-N) can act as tuneable strong ferromagnetic couplers connecting Cu(II) ions; a new complex presenting that bridge with J close to +15 cm(-1) has been suggested and synthesized.     

真空下X2 (X=Cl、Br)与AgOCN气-固反应机理

在真空条件下完成了X2 (X=Cl、Br)与AgOCN间的气-固异相反应，利用紫外光电子能谱（PES）仪，探测与确定反应产物是XNCO (X=Cl、Br)，并推断其可能为一过渡态反应，生成中间络合物，新键产生与旧键断裂同时进行.     

Na2SeO3在Fe电极上还原和吸附机理

采用循环伏安法、恒电势电解法、恒电流阶跃法及交流阻抗法研究Na2SeO3提高锌锰合金电沉积电流效率的作用机理.证明在锌锰合金电沉积的条件下，Na2SeO3 阴极被还原为Se32－并吸附在阴极表面上，从而阻止了氢原子在阴极表面的吸附，因而减少了氢离子的阴极还原.拟定了Na2SeO3的反应和吸附机理，用交流阻抗法进一步证明了所拟机理的正确性.     

Thermodynamic excess quantities in the adsorption of sodium alkylsulfonates at the air-solution interface

Colloid and Polymer Science - Data on the surface tension of sodium alkylsulfonate solutions at different temperatures and surfactant concentrations are presented. By applying the thermodynamic...